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Reprogramming the NiTi expander: an alternative to conventional rapid and slow maxillary expansion modalities for the treatment of patients with cleft lip and palate

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Reprogramming the NiTi expander: an alternative to conventional rapid and slow maxillary expansion modalities for the treatment of patients with cleft lip and palate

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Reprogramming the NiTi Expander:
An Alternative to Conventional Rapid and
Slow Maxillary Expansion Modalities for
the Treatment of Patients with Cleft Lip
and Palate

by
Ana Torres Moneu

A Thesis Presented to the Faculty of the Graduate School of the University of
Southern California in Partial Fulfillment of the Requirements for the Degree
Master of Science in Craniofacial Biology

Los Angeles, May 2018
2
Acknowledgements

I would like to thank Dr. Stephen Yen. Your knowledge, guidance, and mentoring throughout
the creation of this project has been priceless.

Special thanks to Dr. Daniela Garib, Dr. Priscila Ayub, and Dr. Ibtesam AlYazeedi, who
provided part of the data for our study.

I also thank Dr. Hongsheng Tong and Dr. John Pham, who together with Dr. Yen, wrote a
Coulter Foundation Grant that funded the Bender Soarer-X equipment and the NiTi
Expanders for this study.

Finally, I would also like to thank my family for all the support and encouragement
throughout my journey in dental school and orthodontic residency. Mom, Dad, Cristina, and
Paula, I love you.

3
Table of Contents

1. Abstract……………………………………………………………………………...4
2. Introduction………………………………………………………………………….6
a. Background and Significance……………………………………….………8
i. Classification of Clefts……………………………………………..10
• Type 2 Cleft: Cleft Lip and Palate (CLP)………………….13
ii. Development of the Lip, Nose and Primary Palate………………..14
iii. Development of the Secondary Palate……………………………..16
iv. Etiology………………….………………….……………………...18
v. Clinical Presentations………………….…………………………...21
vi. Diagnosis………………….………………….…………………….22
vii. Treatment………………….………………….……………………22
b. Orthodontic Preparation for the Alveolar Bone Graft……………………...33
i. Slow versus Rapid Maxillary Expansion…………………………..33
ii. The Problems that a Patient with CLP Faces………………………34
iii. Period of Stabilization after Expansion…………………………….35
c. The Programmable NiTi Expander…………………..…………………….37
d. Aim of the Study………………….………………….…………………….41
3. Material and Methods………………….………………….………………….……42
a. Sample………………….………………….………………….……………43
b. Measurements………………….………………….……………………….52
c. Statistical Analysis………………….………………….…………………..54
4. Results………………….………………….………………….……………………56
5. Discussion………………….………………….………………….………………..74
6. Conclusions………………….………………….………………….………………84
7. References………………….………………….………………….………………..86
8. Appendix………………….………………….………………….…………………95
a. List of Figures………………….………………….……………………….96
b. List of Tables………………….………………….………………………..99
c. Sample of Consent Form…………………….………………….………...100
d. Sample of Assent Form………………….………………….…………….104
e. Tables with Data………………….………………….…………………...106
4
1. ABSTRACT

Introduction
The NiTi expander is a novel appliance that has several advantages over the other methods
of expansion, such as shape memory, reprogrammability, surgical field non-interference, and
cost. The aim of this study was to analyze the dentoalveolar effects of the NiTi expander in
patients with complete unilateral cleft lip and palate (UCLP) and compare them to the effects
of the current methods of expansion.

Material and Methods
This clinical trial has a sample of 71 patients with complete UCLP, ages 7-14 years, who
were divided in three groups and had expansion with Quad-Helix (QH, Group 1), Rapid
Palatal Expander (RPE, Group 2), or NiTi expander (Group 3) prior to the secondary alveolar
bone graft surgery. Occlusal changes were measured in digital models that were obtained
pre-expansion (T1) and 6 months post-expansion at the time of appliance removal (T2).

Results
There were no statistically significant differences between the three groups at T1 (p<0.05).
All three expanders were capable of expanding the maxillary arch in patients with complete
UCLP. There were statistically significant differences between the groups in posterior
expansion, arch perimeter, and buccal tipping of the first molars (p<0.05). The NiTi expander
and QH were able to produce a differential expansion with more anterior than posterior
expansion; while the RPE over-expanded the posterior segments. Arch perimeter increased
in all groups, but the increase was greater in RPE (6,08mm), followed by NiTi (4.89 mm),
and then QH (2.63 mm). The RPE tipped the first molars buccally 4.39º, the NiTi was able
to control the buccal inclination and tip the molars palatally 3.49º by torqueing the lingual
sheaths, and the QH showed no statistically significant change in buccal tipping.
Complications occurred in 10% of the patients and included detachment of the lingual sheath,
5
wire breakage, non-activation if the SS arms were considerably readapted after
reprogramming the appliance, and wire embedment into the palatal tissue if the expander size
was too large to begin with.

Conclusions
Due to the successful expansion results obtained in this study, ability to customize the NiTi
expander with reprogramming, lack of interference with the surgical field and its reduced
cost, the NiTi expander is a great appliance to provide expansion prior to alveolar bone graft
surgery in patients with complete UCLP, as it adapts to their needs and should be considered
the appliance of choice for the treatment of these patients.

6

2. INTRODUCTION

7
The importance of orthodontic treatment in patients with cleft lip with or without cleft palate
(CL/P) has been a topic of interest because this anomaly is the most common craniofacial
anomaly in the human being and one of the most common birth anomalies reported. The
orthodontic treatment of patients with CL/P is often a challenge for the orthodontist, as these
patients present with differences and limitations in their anatomy and physiology that could
limit or alter the treatment results.

A variety of rapid and slow expansion modalities have been described in the literature and
their different mechanics and outcomes have been compared extensively in patients without
clefts. However, few studies have precisely compared rapid to slow maxillary expansion
modalities in patients with CL/P and no study has compared the NiTi expander to other
appliances in patients with CL/P.

The combination of two previously independently described technologies, the NiTi expander
and the Bender Soarer-X electrical reprogramming of NiTi wires, offers distinctive
advantages over conventional expansion appliances for the orthodontic treatment of patients
with CL/P because of the ability to customize expansion to the patient with minimal patient
visits. This is the first study to analyze the effects of the reprogrammable NiTi expander in
patients with CL/P.

The purpose of this study is to analyze the dentoalveolar effects of the programmable NiTi
expander in patients with complete UCLP (unilateral cleft lip and palate) and compare the
results to the ones of two conventional expansion appliances, the Rapid Palatal Expander
(RPE) and the Quad-Helix (QH). If proven to have similar treatment outcomes, the
programmable NiTi Expander could be an alternative to the RPE and QH for the treatment
of patients with CL/P that can make their treatment more efficient and predictable.

8
a. Background and Significance

There are four general types of developmental pathology leading to structural defects:
malformation, deformation, disruption and dysplasia (Jones et al., 2013).
1. Malformation: poor formation of tissue. Example: cleft palate.
2. Deformation: unusual forces on normal tissue cause an alteration. May be secondary
to extrinsic forces, such as uterine constraint on a normal fetus, or to intrinsic forces
related to a more primary malformation. Example: superior and posterior positioning
of tongue due to micrognathic mandible.
3. Disruption: result of breakdown of previously normal tissue. Example: amniotic band
constriction.
4. Dysplasia: lack of normal organization of cells into tissue. Example: Hamartoma,
fibrous dysplasia.

There are many types of malformation depending on the nature of the poor formation (Jones
et al., 2013):
1. Incomplete morphogenesis: lack of development, hypoplasia, incomplete separation,
incomplete closure, incomplete septation, incomplete migration of mesoderm,
incomplete rotation, incomplete resolution of early form, and persistence of earlier
location.
2. Aberrant form: occasional anomaly.
3. Accessory tissue: additional tissue or structures.
4. Functional defects: functional defects resulting from primary malformations.

A cleft is a type of incomplete malformation, where there is a lack or incomplete fusion
between structures during development. There are different developmental fields and their
normal fusion is supposed to happen during the embryonic stage of pregnancy. When the
process of fusion is interrupted, a cleft can occur and depending on when development is
disturbed, the cleft will affect one structure or another. Clefts involve a great variety of
structures and their severity varies considerably, affecting soft tissue, bony structures, or both
in different degrees. The most common presentation is unilateral, but cleft lip can present as
9
bilateral clefts. Although there is a pattern for all the clefts and they tend to follow the same
line of fusion, their clinical presentation is never the same between two patients.

According to Kjaer (Kjaer, 2010), she describes five different developmental fields in the
craniofacial complex (Figure 1): frontonasal, maxillary, palatine, mandibular, and cerebellar
fields. The location of the cleft will depend on which developmental fields are affected.

A

B
{
C
{
Figure 1. Developmental fields
A) Schematic drawings of the different cranial fields. Top row, from left to right: the frontonasal,
maxillary, and palatine fields. Bottom row, left: the mandibular field, right: the cerebellar field.
B and C) Different developmental fields are marked on the radiographs. Green: cerebellar and
cervical spine. Purple: theca. Light and dark blue: mandibular. Yellow: frontonasal. Red: maxillary.
Orange: palatine. Note that sella turcica is a borderline region between many fields.

Images from (Kjaer, 2010)
10
Classification of Clefts
Human development occurs in a well-planned and sequential manner; thus, depending on
when development is disturbed, the cleft can alter the formation of surrounding structures
and tissues.

There have been several attempts to classify craniofacial clefts, but the Tessier classification
is the most generally accepted classification (Figure 2). It was first described in 1976 by Dr.
Paul Tessier (Tessier, 1976), a French plastic surgeon considered pioneer of modern
craniofacial surgery. The classification ranges from 0 to 14 and is centered on the orbit, which
separates the facial structure and the cranium. The facial clefts are numbered from 0 to 7 and
the cranial clefts from 8 to 14 in a counter clockwise rotation (Tessier, 1976).

Figure 2: Tessier classification of facial and cranial clefts: Localization on the soft tissues (a) and
skeleton (b). Dotted lines are either uncertain locations or uncertain clefts. Image from: (David, Moore
and Cooter, 1989)

11
A total of 15 different Tessier clefts can be distributed into 4 groups, based on their position
(Fearon, 2008; Tessier, 1976):

I. Midline clefts (Tessier clefts 0, 14 and 30): they divide the face vertically
through the midline. Tessier 0 goes through the maxilla and the nose, Tessier 14
through the nose and the frontal bone, and Tessier 30 through the tongue, lower
lip and mandible.

II. Paramedian clefts (Tessier clefts 1, 2, 12, and 13): similar to the midline clefts,
but further away from the midline of the face. Tessier 1 and 2 go through the
maxilla and the nose, with number 2 being further away from the midline than
number 1. Tessier 12 and 13 are the extents of number 2 and 1 respectively and
go through the nose and the frontal bone, both between the midline and the orbit
with number 12 further away from the midline than number 13. Type 2 is a cleft
of the lip, alveolus, and palate (CLP), which is the most frequent cleft.

III. Orbital clefts (Tessier clefts 3, 4, 5, 9, 10, and 11): all these clefts affect the
orbit. Numbers 3, 4, and 5 go through the maxilla to the floor of the orbit.
Numbers 9, 10, and 11 are the extents of numbers 5, 4, and 3 respectively and
affect the frontal bone in the area of the upper part of the orbit, with number 9
further away from the midline than number 10, which is further away than 11.

IV. Lateral clefts (Tessier clefts 6, 7, and 8): these clefts are horizontal. Number 6
and 8 affect the orbit and cheek bone, with number 8 starting higher in the orbit
than number 6. Number 7 goes from the commissure of the mouth towards the
ear in either direction.

12

Table 1. Equivalence of Tessier to Fearon’s classification of clefts.

Tessier Number Type of Cleft
0-14
30
Midline clefts
1-13
2-12
Paramedian clefts
Type 2: CLP (most frequent cleft)
3-11
4-10
5-9
Orbital clefts
6-7-8 Lateral clefts
Figure 3. Fearon’s surgical classification of clefts: median clefts, paramedian
clefts, orbital clefts, and lateral clefts. Image from (Fearon, 2008).
13
Type 2 Cleft: Cleft Lip and Palate (CLP)

The most frequent presentation of orofacial clefting is cleft lip with or without cleft palate
(CL/P) (Gibson and Shetye, 2017; Yoon et al., 2000), the Tessier 2 cleft, which is an anomaly
that results from altered embryonic development that has been attribute to genetic,
environmental or combined causes. CL/P are a world-wide problem that occur on average in
1:700 live births (Dixon et al., 2011; Stone, 2013). Its prevalence varies within ethnic groups,
and varies according to geographic origin, environmental exposures and socioeconomic
status (Dixon et al., 2011). The Native Americans (Atabascan and Navajo Indians) are the
group with the highest incidence with 1:267 live births (Stone, 2013), followed by the Asians
with 1:500 live births (Dixon et al., 2011). The birth prevalence among Caucasians is 1:1000
(Dixon et al., 2011) and the least affected individuals are the African Americans with 1:2500
live births (Dixon et al., 2011). The combined presentations of CL/P make it the most
common craniofacial birth defect in the humans and one of the most common birth anomalies
reported, with a higher prevalence than Down Syndrome (Parker et al., 2010).

The frequency of CL/P also differs by sex, side, and type. CL/P occurs two times more
frequently in males than females (2:1 male to female), while isolated CP occurs in females
twice as often than in males (1:2 male to female). About 75% of the affected individuals have
a cleft lip (50% combined CLP and 25% isolated CL), while the other 25% are isolated CP
(Stone, 2013). Unilateral clefts are more common than bilateral clefts with a ratio of 4:1, and
for unilateral clefts, about two thirds occur on the left side of the face (2:1 left to right) (Dixon
et al., 2011).

Historically, clefts of the lip and/or palate were generally divided into two groups: isolated
cleft palate (CP) vs. cleft lip with or without cleft palate (CL/P) (Dixon et al., 2011; Mossey
et al., 2009). However, recent studies have suggested that isolated cleft lip (CL) might have
unique etiologic features (Dixon et al., 2011). This subdivision of CL/P is consistent with the
different developmental origins of the lip and primary palate and secondary palate (Dixon et
al., 2011).

14
Development of the Lip, Nose and Primary Palate
The face develops from neural crest cell migration into branchial arches of the face. During
the 5th-10th week of pregnancy four primordia that surround a central depression, the
primitive oral pi (Figure 4):
1. The frontonasal process, is a single process that migrated over the top of the head
to a position located above the oral pit and has one medial and lateral nasal
prominence on each side.
2. Two maxillary processes developed laterally toward the midline nasal process. It
is lateral to the oral pit, which arise from the 1
st
pharyngeal arch.
3. The mandibular prominence located below the pit, which arises from the 1
st

pharyngeal arch develops laterally and meets at the midline.

Late in the 4
th
week, nasal placodes develop bilaterally at the lower margin of the frontonasal
process, which become recesses and form the nasal pits. As the pits deepen, they form the
nostril including the median and lateral nasal processes. Over the next few weeks, the lateral
structures of the face grow exponentially, thus pushing the maxillary, as well as the lateral
and medial nasal prominences towards the midline. During the 6
th
-8
th
week, the two medial
nasal processes merge in the midline to form the intermaxillary segment. This will later form
the philtrum, primary palate and tip of the nose (Figure 5). The maxillary processes don’t
meet at the midline, instead, they meet the medial nasal prominences. As the maxillary and
medial nasal processes come into contact, they fuse to form a "nasal fin". A lack of fusion
between them results in a cleft lip (Figure 5). Finally, the nose forms from the frontonasal
process, medial nasal processes (2), and lateral nasal processes (2) (Figure 4).

As suggested, the primary palate which later becomes the premaxilla, is related
developmentally more to the midline structures of lip than to the majority of the hard and
soft palate forming the palatal shelves. Therefore, it is possible to have a cleft in the alveolus
along with a cleft lip, while the rest of the palate is intact (Grosen et al., 2010).
15

A

B

Figure 4. Development of the face: median nasal prominences(yellow), lateral nasal
prominences (blue), maxillary prominences (red).

Images from: https://web.duke.edu/anatomy/embryology/craniofacial/craniofacial.html
Figure 5. Representation of the developmental fields in the palate and face.
A) Schematic drawing of the human palate indicating the frontonasal (yellow), maxillary (red), and palatine (orange)
fields. B) Field contours on a photograph of a child aged 2 months with a cleft lip. The colors are the same as in image
A, additionally the mandibular field is marked in blue. Note that the cleft lip is located at the border region between the
frontonasal and maxillary field. Images from (Kjaer, 2010)

16
Development of the Secondary Palate
The secondary palate involves hard and soft palate and its fusion occurs later in gestation,
between 8-12 weeks of development. It forms from two outgrowths of the maxillary
prominences called the palatine shelves. There are five steps in palatine shelf positioning that
lead to the closure of the secondary palate:
1. Step 1: Earlier in development, the palatine shelves project downward on either
side of the tongue (Figure 6), because tongue occupies the space between the
palatine shelves.
2. Step 2: As the embryo develops, there is vertical growth of the mandible, resulting
in a downward repositioning of the tongue.
3. Step 3. This downward movement of the tongue allows the palatine shelves, to
upright like a drawbridge and grow towards the midline.
4. Step 4. After the shelves assume a horizontal position overlying the tongue, there
is a final growth spurt causing them to make contact in the midline.
5. Step 5: The contact of the palatine shelves in the midline leads to closure and
fusion of the secondary palate, through a process of epithelial-mesenchymal
transformation of leading edge epithelial cells. The fusion of the processes
completes the development of the maxillary and palatine developmental fields
(Figure 5):
a. Initial closure or fusion of lateral palatine shelves first occurs immediately
posterior to the median palatine process (primary palate).
b. After that, closure takes place gradually over several weeks in a posterior
direction by the merging of the two lateral palatine processes. When
merging, the depth of the groove separating the processes is diminished.

In order for the secondary palate to fuse, the tongue has to descend to let the palatine
processes come together. Interruption of the movements of facial processes during palate
formation results in failure of fusion of the palatine shelves and a cleft palate. This failure
can result from disturbances of the process in any of the above-mentioned steps, not only at
step 5. For example, a failure in the downward growth or positioning of the mandible at step
2 can interfere with the downward repositioning of the tongue. If the tongue does not descend
correctly, it will be a physical barrier and fusion of the palate will be altered, causing a cleft
17
in the secondary palate.

The closure of the secondary palate follows that of the primary palate by 2 weeks, which is
why an interference with lip closure often interferes with palatal closure. About 60% of
individuals with cleft lip also have cleft palate.

A

B

C

Figure 6. Closure of the secondary palate
A. Palatine shelves projecting down vertically on either side of the tongue. The tongue is positioned
higher than the palatine shelves.
B. Palatine shelves positioned higher than the tongue after vertical growth of the mandible and
downward movement of the tongue has occurred.
C. Palatine shelves have fused in the midline, separating the oral and nasal cavities.

18
Etiology:

It is important to distinguish between clefts associated with a syndrome (syndromic clefts)
and those that have no other apparent cognitive or structural abnormalities associated
(isolated non-syndromic clefts). In addition to cleft lip and palate, syndromic clefts have
additional minor and/or major malformations that occur together with the cleft. Their
syndromes can follow a single gene inheritance pattern as described by Mendel (Gibson and
Shetye, 2017). It is estimated that 30% of the CL/P and 50% of the isolated CP are present
as part of a syndrome (Dixon et al., 2011). There have been more than 500 Mendelian
syndromes associated with CL/P that can be reviewed at OMIN (the Online Mendelian
Inheritance in Man), as well as other syndromes arising of chromosomal or
environmental/teratogenic effects (Dixon et al., 2011).

The majority of CL/P (70%) are isolated non-syndromic entities (Dixon et al., 2011). The
etiology of isolated CL/P has been extensively studied; nevertheless, the genetic mechanism
of this complex multigenic birth defect is not known. Non-syndromic CL/P are thought to
follow a multifactorial model of inheritance and may occur secondary to multiple
environmental and genetic risk factors that accumulate to a point that crosses the threshold
line for phenotypic expression (Dixon et al., 2011; Grosen et al., 2010; Murray, 2002). The
majority of patients have no identifiable cause, because it is very difficult to determine
specific etiologic factors, as the defects arise in early stages of embryological development
and have a complex etiology with multiple genes having major and minor roles, as well as
environmental factors and variable recurrence rates (Dixon et al., 2011). There is little
evidence for a clear-cut Mendelian inheritance and most cases appear sporadic (Jugessur et
al., 2009).

According to Murray’s group at the University of Iowa(Dixon et al., 2011), there are at least
eleven genes with a confirmed or likely role in non-syndromic CL/P and others that have
been related and intensively studied but have no convincing evidence yet (Table 2) (Dixon
et al., 2011). Furthermore, more genes are likely to be identified by global approach
association studies using SNP markers.

19
Table 2. Genes with a role in non-syndromic CLP. (This table is a replication from Table 2
in (Dixon et al., 2011))

Class / Gene Evidence*
Confirmed
IRF6 GWA, LD, L, M
8q24 locus GWA, LD
VAX1 GWA, LD
Likely
MSX1 LD, M
FOXE1 L, LD, M
MYH9 LD
MAFB GWA
ABCA4 (locus only) GWA
17q22 locus GWA
BMP4 M
FGFR2 M
Intensively
Studied
TGFA LD
TGFB3 LD, M
MTHFR LD
GSTT1 LD
PDGFC LD, M
FGF8 M
PVRL1 M, LD
SUMO1 M
CRISPLD2 LD

*GWA= Genome-wide association, LD=Candidate Gene Association, L = Linkage, M = Mutation Detection

Genetic diagnosis and determination of cleft etiology is very important to be able to provide
parents with counseling regarding the recurrence risk in future pregnancies, other possible
anomalies associated, as well as prognosis of their child with a facial cleft. A great range in
20
phenotypic expression suggests that analyzing and classifying the different phenotypes is
important to further understand the genetic heterogeneity underlying non-syndromic CL/P
(Marazita et al., 2009). Subdivision by phenotypes could include phenotypic features like
dental anomalies, lip pits, defects of the orbicularis oris muscle, brain variants, speech or
cognitive differences, submucous CP, ankyloglossia, and bifid uvula (Dixon et al., 2011).

Although the percentage of cases directly linked to genetic factors is estimated to be about
40%, all clefts appear to show a familial tendency with incomplete penetrance (Stone, 2013).
Thus, family history is a strong risk factor for development of a CL/P and not only the
affected individuals, but also their “unaffected” family members, should be screened in order
to determine other phenotypic features present that could give a better understanding of the
genetic component of the cleft within each family. Furthermore, a family member without
clefts with a phenotypic feature present could be a genetic marker for incomplete penetrance
and thus a risk factor for a future child with CL/P.

Environmental factors also play a role in the development of CL/P, especially if combined
with genetic factors. The best short term preventive measures should be directed to eliminate
these environmental/teratogen factors, which include maternal smoking, alcohol
consumption, exposure to teratogen medications, stress, maternal obesity, infections, and
exposure to ionizing radiation, during the first trimester of pregnancy, which is the time of
lip and palate formation (Dixon et al., 2011; Murray, 2002; Shi et al., 2007; 2008). Folate
deficiency has also been suggested to increase the risk for CL/P (Grosen et al., 2010; Wehby
and Murray, 2010); however, studies regarding this matter still remain controversial (Wilcox
et al., 2007). Further studies about nutrients and micronutrient deficiency need to be
performed to determine the roles of zinc deficiency in oral clefts, cholesterol deficiency in
facial clefts, and multivitamins supplements in cleft prevention (Dixon et al., 2011).

To better characterize etiologies and provide access to better clinical care and prevention, it
will be necessary to integrate genetic and environmental risks using epigenetics, systems
biology, gene expression and epidemiology (Dixon et al., 2011).

21
Clinical Presentations of CL/P:

The severity of a CL/P varies between individuals, ranging from a simple skin “notch” or
small bridle in the oral mucosa to a complete cleft. Complete clefts (Figure 7) affect both the
primary and secondary palate, thus resulting in a cleft lip, alveolar bone, hard and soft palate.
Unilateral clefts occur four times more than bilateral ones (4:1). Bilateral clefts are more
severe and the patient has the vomer exposed, which is usually covered by mucosa that can
get irritated and break down, leading to pain for baby when feeding.

Incomplete clefts (Figure 8) vary on its presentation and affect the primary or secondary
palate only, which can also be completely or partially affected. Different types of incomplete
clefts are cleft lip (CL), cleft palate (CP), and partially affected CL or CP, such as bifid uvula,
submucosal cleft, and partial alveolar cleft.

A

B

A

B

C

D

Figure 7. Complete forms of CLP. A) Unilateral; B) Bilateral
Figure 8. Different forms of incomplete CLP. A) Isolated cleft lip; B) Submucosal cleft; C) Bifid uvula; D) Isolated cleft palate.

22
A bifid uvula (Figure 8 C) is a partial cleft of the palate that affects the soft palate only. A
submucosal cleft (Figure 8 B), which is a cleft that affects only the bony structures of the
palate and has therefore intact soft tissue. Usually it is possible to recognize a clear zone in
the midline called “zona elucida”, which is the cleft of the bony structures being seen through
the mucosa of the soft palate, as well as a palpable notch at posterior border of the hard palate.

Diagnosis

A CL/P is usually diagnosed in a routine prenatal ultrasound when it involves the lip. Isolated
CP might be a more difficult to diagnose prenatally, because it can only be seen if the fetus
opens his/her mouth, for example to yawn. Diagnosing a cleft prenatally is advantageous to
be able to prepare the parents and provide them with information and counseling (Johnson
and R Sandy, 2003; Vig and Mercado, 2015). However, sometimes they are not accurately
diagnosed until the patient is born, for example if the fetus does not turn or covers his mouth,
or if he/she does not open the mouth in an isolated CP.

It is important to explore the whole craniofacial complex very carefully in order not to miss
other features or affected structures when the CL/P is first detected. Pediatricians and
geneticists need to identify whether other anomalies are present, in order to determine if it is
a sporadic cleft or if it is part of a syndrome. When three or more minor malformations such
as a cleft lip and palate occur in a given newborn, over 90% will also have a major
malformation which can be life-threatening.

Treatment

Treatment of patients with a CL/P is usually carried out in stages while the patient is actively
growing. Successful rehabilitation requires a team approach of different but collaborating
dental and medical specialties (Pan et al., 2007; Yang, Pan, Qian and Wang, 2012; Raju et
al., 2014; Grosen et al., 2010; Abdoney, 1995; Gibson and Shetye, 2017) (Vig and Mercado,
2015). Several studies conducted in the United Kingdom showed an improvement in facial
23
appearance, dentoalveolar relationships, speech, self-confidence and length of hospital stay,
after centralization of CL/P care support compared to before, which is why this is the most
common approach today (Al-Ghatam et al., 2015; Fitzsimons et al., 2012; Gibson and Shetye,
2017; Sell et al., 2015; Waylen et al., 2015). Different members and roles of the cleft team
are the following:

• Pediatrician: initial systemic examination, monitoring growth and development,
treatment and re-assessment of associated medical condition.

• Geneticist: genetic diagnosis, determination of cleft etiology, recurrence risk and
prognosis counseling.

• Nurses: frequently act as team coordinators, patient education and support,
monitoring growth and development.

• Surgeons (plastic, oral and maxillofacial): lip adhesion, primary repair surgeries
(cheiloplasty, nasoplasty, gingivoperiosteoplasty, palatoplasty), alveolar bone graft,
surgical intervention for velopharyngeal dysfunction, and orthognathic surgery.

• Otolaryngologist (ENT): most patients can develop hearing problems due to middle
ear infections, secondary to fluid accumulation. The otolaryngologist will have to
perform regular hearing tests and monitor for middle ear disease. The patients may
need to undergo surgical procedures such as myringotomies for the placement of
tympanic tubes. Regular follow up examinations during adolescence are important,
as well as maintenance of hearing assistance devices.

• Speech therapist: speech might be affected due to anatomical reasons, as well as
secondary to hearing problems. A good evaluation of articulation, resonance,
phonation / voice, and language development is important to determine if speech
therapy or other treatments are indicated.

• Psychologist / social worker: their role is important to promote the well-being of the
24
patient and family members and for the treatment of emotional, learning,
developmental, and adjustment disorders. It can help the patient to overcome difficult
social situations, such as being teased at school, and prevent them from suffering from
decreased self-confidence and depression. Patients can also have learning problems
or developmental delay (Gibson and Shetye, 2017).

• Pediatric dentist: promoting oral hygiene instructions to the patient and the family
members, treatment of pathology of the dentition. These patients have an increased
prevalence of dental anomalies and are in high risk of caries due to long periods of
orthodontic treatment and multiple surgeries in the oral region (Akcam et al., 2010;
Gibson and Shetye, 2017).

• Orthodontist: as members of the cleft team, orthodontists are going to intervene at
different stages of development of CL/P patients. The treatment modalities are
diverse and include: nasoalveolar molding to facilitate the lip repair at an early age,
orthodontic expansion prior to the alveolar bone graft surgery, comprehensive
orthodontic treatment to correct crowding and maxillary hypoplasia, and in some
cases orthognathic surgery (Abdoney, 1995; Pan et al., 2007; Vasant et al., 2009;
Yang et al., 2012).

• Prosthetic / restorative dentist: replacement of missing teeth and / or fabrication of
removable appliances for fistula obturation or the treatment of velopharyngeal
dysfunction (Gibson and Shetye, 2017).

The following is the typical sequence of the treatment of a sporadic CLP with no other
anomalies associated and will be described in detail below. The treatment and timeline are
based on the patient’s age and development and may vary depending on the characteristics
and development of each patient.
1. Pregnancy: diagnosis, information and support
2. Age 0-3 months: feeding assistance, weight gain and nasoalveolar molding (NAM)
3. Age 3-4 months: cheiloplasty (lip repair)
4. Age 9-12 months: palatoplasty (palate repair) and myringotomy
25
5. Age 1-3 years: speech development
6. Age 3-7 years: regular team visits
7. Age 7-12 years: first phase of orthodontic treatment and alveolar bone graft
8. Teenage years: second phase of orthodontic treatment and cosmetic dentistry
9. End of growth: orthognathic surgery, dental implants and rhinoplasty

An initial evaluation by a pediatrician is required shortly after birth to rule out other
anomalies present. Patients with syndromic clefts may need medical evaluation and treatment
of other symptoms or defects in addition to the cleft.

1. Pregnancy: Diagnosis, Information and Support
If the cleft has been identified by ultrasound it is important to explain to the parents what is
going on, give them the information, and prepare them for what is coming.

2. Age 0-3 Months: Feeding Assistance, Weight Gain and Nasoalveolar Molding (NAM)
The baby and family will meet the craniofacial team pediatrician and nurses to learn about
feeding considerations, such as position of the baby, special bottles, etc. At one month the
team pediatrician and nurses will evaluate the baby regularly to ensure that it is gaining
weight and developing properly. It is important to make sure that they stay in their percentile.

Some babies need to undergo nasoalveolar molding (NAM) treatment prior to cleft lip repair
surgery. NAM is an adjunctive neonatal therapy for the facilitation of the surgical lip closure.
This technique consists of an acrylic intraoral appliance with nasal stents used to mold the
nasal cartilages, premaxilla, and alveolar ridges into a normal shape and position during the
neonatal period to approximate the alveolar segments, reducing the severity of the deformity
prior to surgery and thereby enabling the surgeon to achieve a better repair and perform a
gingivoperiosteoplasty successfully (Figure 9) (Grayson, Santiago, Brecht and Cutting, 1999;
Shetye and Grayson, 2017). It takes advantage of the malleability of immature nasal cartilage
and its ability to maintain a permanent correction of its form (Grayson et al., 1999). The
presence of a high level of hyaluronic acid in the infant helps to mold the tissue. In bilateral
clefts it also lengthens the columnella through constant stretch by gradually elongating the
nasal stents (Lee et al., 2008), creating more soft tissue for the lip repair and therefore
26
reducing the resultant scar tissue (Shetye and Grayson, 2017). The baby is seen for weekly
adjustments of the appliance bring the alveolar segments together and elongate the soft tissue
at the columnella (Shetye and Grayson, 2017).

Long term studies have shown better lip and nasal form, as well as less scar tissue in patients
that underwent NAM therapy, which reduced the number of surgical revisions for nasal and
labial deformities, excessive scar tissue, and oronasal fistulas (Barillas et al., 2009; Maull et
al., 1999; Patel et al., 2015; Peanchitlertkajorn et al., 2018; Vig and Mercado, 2015).
Additionally, Santiago et al. (Santiago et al., 1998) found that 60% of the patients that
received NAM therapy and gingivoperiosteoplasty did not need a secondary alveolar bone
graft surgery and the other 40% although needing a secondary alveolar bone graft, had more
bone remaining in the graft site compared to those who did not have a gingivoperiosteoplasty
due to too distant alveolar segments (Santiago et al., 1998; Sato et al., 2008).

A

B

C

Figure 9. NAM Appliance.
A. Diagram of a patient with bilateral CLP wearing a NAM appliance. Image from
http://www.eotruebloodillustration.com/cleft-lip/
B. Image of a baby with bilateral CLP wearing a NAM appliance. Image from:
http://www.cleftopedia.com/pre-surgical-techniques/nam/
C. NAM appliance. Image from:
http://www.webring.org/l/rd?ring=wide;id=61;url=http%3A%2F%2Fouremily%2Eblogspot%2Ecom%2F2004
%2F05%2F

27
3. Age 3-4 months: Cheiloplasty (Lip Repair)
The lip repair is performed after NAM, usually at approximately 3 months of age, because
surgery and anesthesia become safer. The rule of 10s is usually a good estimate of whether
the baby is ready for the cleft lip repair surgery: when its weight is 10 pounds and
Hemoglobin 10 grams, which usually happens around 10 weeks of age. Ideally, the distance
from the nasal columnella to the apex of cupid’s bow should be 10 mm.

4. Age 9-12 Months: Palatoplasty (Palate Repair) and Myringotomy
Palate repair is usually performed at 9-12 months of age. Due to the cleft, the palatal muscles
need to be disinserted and reattached to restore function. To repair the cleft palate, the
surgeon needs to reattach the muscles and close the mucosa, but does not need to perform a
bone graft in the area. It is important that a two-layer closure is performed in the hard palate
(nasal mucosa and oral mucosa) and a three-layer closure in the soft palate (nasal mucosa,
muscle, oral mucosa) to avoid an oronasal fistula. It is better if the child can drink from a cup
already by the time of palate repair, to avoid nipples or anything into the mouth that could
break the sutures.

From an anesthesia point of view, it is helpful for the baby to weigh 20 lbs for longer
operations. Repair of the palate is timed to minimize the potential growth risks, and to allow
for the production of normal speech when the patient is just beginning to develop the ability
to produce sounds for which the palate is necessary (Abdoney, 1995). Speech development
occurs around 10 months, which is why this is a good time to operate the palate. The physical
change that the surgery produces is only part of the correction. The speech therapist has to
“reprogram” the patient and teach them how to produce the new sounds with the post-surgical
anatomy.

Sometimes the babies can develop hearing problems, which can also lead to speech problems.
Besides being important for speech production, the muscle tensor velli palatine also helps to
depressurize and clear fluids of the middle ear (Gibson and Shetye, 2017). The tympanic
membrane is an epithelium layer that separates the external from the internal ear drum
(Figure 10). A Eustachian tube connects the inner ear canal to the mouth and its function is
to maintain the pressure inside the ear drum equal to the pressure of the environment. When
28
the palate is intact, the tensor velli palatine opens the Eustachian tube when we swallow and
the pressure inside the ear drum equalizes the pressure outside the ear drum. If the palatal
muscles are not functional in controlling the opening of the Eustachian tube in the posterior
pharynx as in a patient with a cleft palate, there is inefficient Eustachian tube function, which
leads to fluid buildup and ear infections. If the middle ear space fills with liquid, the tympanic
membrane will not function properly, which will lead to the ear bones not functioning
properly as well, causing the patient hearing problems, which can also affect speech
development.

Patients need to be assessed for fluid buildup by an otoloaryngologists prior to palatoplasty.
If indicated, a myringotomy (Figure 10) can be performed at the time of palatoplasty to place
pressure equalizing ear tubes in the Eustachian tube to drain the fluid and prevent infections,
as well as hearing loss (Gibson and Shetye, 2017).

5. Age 1-3 Years: Speech Development
During this time patients are usually evaluated every 6 months until they are 3 years old, then
annually until treatment is completed. Between the ages of 1-3 years the patient continues to
develop speech and needs to be followed closely by speech therapists to determine if they
have velopharyngeal insufficiency. Depending on how the speech is, treatment might involve
Figure 10. A. Anatomy of the ear; B. Diagram of a myringotomy.
Images from http://craniofacialteamtexas.com/cleft-lip-and-cleft-palate/what-causes-cleft-lips-and-palates/
29
speech therapy or additional surgery, such as a pharyngeal graft. Dental evaluations and
treatment should also be performed every 6 months beginning at 1 year of age.

6. Age 3-7 Years: Regular Team Visits
Patients should have annual cleft team visits to do a full evaluation, including speech
assessment and dental checkups. Some patients will need revision surgeries for the lip or
nose for esthetic and social reasons (Grosen et al., 2010).

7. Age 7-12 Years: First Phase of Orthodontic Treatment and Alveolar Bone Graft
Between the ages of 7-12 years, the patients whose clefts include the alveolus will undergo
orthodontic expansion and alveolar bone graft surgery to repair it. The objective of maxillary
expansion is to increase the transverse width of the maxillary dental arch at the apical base
with minimal dental tipping of the posterior teeth within the alveolus. This procedure was
first described for the non-cleft patient in the 19
th
century and later reintroduced by Haas
(Haas, 1961). The technique consists on an appliance, which transmits forces to the teeth and
supporting structures to separate mechanically the maxillary halves at the midpalatal suture.
The rate of expansion depends on the appliance used, the amount of force it transmits, the
number of activations per day, and the stage of development and maturity of the patient.

For the patient with a complete cleft lip and palate, once the maxillary segments are expanded
and aligned into an archform, the alveolar bone graft surgery will be performed by an oral or
plastic surgeon, typically using autologous bone from the iliac crest, which is an area of
abundant cancellous bone and the gold standard in the 21
st
century (Bergland et al., 1986;
Vig and Mercado, 2015) (Figure 11). The bone graft should be the width of the alveolar ridge
and the height of the maxilla to the level of the nasal floor. Suture closures are used to seal
the nasal and oral mucosa in order to hold the bone graft between the oral and nasal cavities.

The timing of this surgery depends on many factors, such as the transverse width of the
maxilla, the archform, the timing of the eruption of the permanent teeth in the area of the
cleft, and whether the alveolar segments are collapsed into the cleft space or not. Orthodontic
assessment of dental development is important to determine the timing of the alveolar bone
graft surgery, with the goal of performing the graft early enough to allow the erupting
30
permanent teeth to have good alveolar support, but as late as possible to limit the negative
side effects on the growth and development of the maxilla (Gibson and Shetye, 2017;
Wirthlin, 2017). Several studies have shown greater success if the graft is performed before
the maxillary canine adjacent to the cleft erupts, so that it erupts through the graft and brings
bone with it (Gibson and Shetye, 2017; Enemark, Sindet-Pedersen and Bundgaard, 1987;
Freihofer et al., 1993; Turvey, Vig, Moriarty and Hoke, 1984; Bergland, Semb and Abyholm,
1986; Newlands, 2000; Meyer and Mølsted, 2013; Vig and Mercado, 2015). If the canine
erupts prior to the bone graft, it will make the surgical access difficult and predispose the
tooth to loss of periodontal attachment in the area of the cleft site after orthodontic movement
(Wirthlin, 2017). Therefore, most centers advocate secondary alveolar bone grafting when
the unerupted canine of the cleft side has one half to two thirds of its root developed (Wirthlin,
2017). This timing of a bone graft can change if a lateral incisor is erupting into the cleft
space requiring an earlier bone graft.

The goals of the alveolar bone graft are:
1. Provide bony continuity between the cleft segments
2. Stabilize the width of the palate
3. Closure of the remaining soft tissue fistulas adjacent to the cleft
4. Provide support to the nose
5. Provide adequate bone to support the eruption of the permanent teeth (usually the
canine), and orthodontic tooth movement.

It is very important that no tooth alignment with braces is attempted next to the cleft space
before the bone graft is performed, because this root movement out of the alveolar bone could
result in loss of periodontal attachment in the teeth adjacent to the cleft site (Vig and
Mercado, 2015).
31

8. Teenage years: Second Phase of Orthodontic Treatment and Cosmetic Dentistry
The second phase of orthodontic treatment consists of comprehensive treatment to correct
the crowding and occlusion with full fixed appliances and the maxillary hypoplasia with
growth modification or orthognathic surgery depending on the severity of the discrepancy.
Thus, some of these patients may be treated by facemask and/or orthodontics alone, while
others with larger skeletal discrepancies will require orthognathic surgery (Daskalogiannakis
and Mehta, 2009; Gibson and Shetye, 2017; Vig and Mercado, 2015). The introduction of
bone-anchored auxiliaries, such as miniscrews and miniplates, enable the treatment of
moderate discrepancies without orthognathic surgery (Baek et al., 2010; De Clerck et al.,
2009; Vig and Mercado, 2015). If the patient needs orthognathic surgery, this second phase
of orthodontics may be delayed until they are finished growing.

Treatment of missing lateral incisors can be performed by mesializing the canine into the
lateral incisor space (canine substitution) or by replacing the missing teeth with an implant
after completion of orthodontic treatment (Vig and Mercado, 2015; Wermker et al., 2014).
In case of planning dental implants, these will have to be delayed until the patient finished
growth as well. A temporary solution, such as a Maryland bridge, can be offered to the patient
until implants are possible.

Iliac crest Alveolar cleft
Bone graft
Figure 11: Secondary alveolar bone graft surgery being performed. Bone harvested from the iliac crest of the
same patient. (Images from the Children’s Hospital Los Angeles)
32
9. End of Growth: Orthognathic Surgery, Dental Implants and Rhinoplasty
As mentioned above, if the patient requires orthognathic surgery this procedure will be
delayed until the end of growth. To prepare the dentition for the surgery, presurgical
orthodontic treatment will be necessary to decompensate arches (usually 1-1.5 years of
length), as well as postsurgical orthodontic treatment for detailing (6 months of length). The
surgery can involve the maxilla (LeFort I) or both jaws (Lefort I + Bilateral Sagittal Split
Osteotomy or Intraoral Vertical Ramus Osteotomy). Good communication between the
orthodontist and oral surgeon is critical, as many decisions have to be made together. Lingual
sheaths can help to maintain post-surgical transverse expansion with transpalatal arches.

After completion of growth and orthodontic treatment, more aggressive prosthodontic
restorations and implants can be performed to replace missing teeth and ensure optimal
function and esthetics (Wermker et al., 2014).

The final stage in the treatment of many patients with CL/P is the rhinoplasty, which is also
delayed until the patient finishes growth (Vig and Mercado, 2015). Other lip revision
surgeries can also be performed at this point (Vig and Mercado, 2015).

Of the different treatment stages for cleft lip and palate, the present study focuses on the
preparation for alveolar bone graft surgery with orthodontic expansion, which will be
reviewed below.

33
b. Orthodontic Preparation for the Alveolar Bone Graft

Slow versus Rapid Maxillary Expansion

Different orthodontic appliances can be used to provide this expansion with rapid and slow
procedures. Rapid maxillary expansion (RME) uses heavy forces for a short period of time,
usually 1-3 weeks, depending on the amount of expansion desired and the frequency of daily
activations (Ciambotti et al., 2001; Hicks, 1978; Zimring and Isaacson, 1965). These type of
expansion requires patient cooperation activating the expansion screw and might induce
patient discomfort (Ciambotti et al., 2001). On the other hand, slow maxillary expansion
(SME) uses lighter forces for a longer period of time, which has been shown to allow for a
more physiological adjustment to the separation of the sutures with less potential for relapse
(Ciambotti et al., 2001; Storey, 1973). It is widely accepted that both RME and SME lead to
a combined skeletal and dentoalveolar effect (Figure 12). Thus, increased dental arch width
is usually a combination of skeletal widening of the maxilla, tooth movement, alveolar bone
bending, and differences in the rotational plane of the maxilla during expansion (Ciambotti
et al., 2001; Haas, 1961; Isaacson and Murphy, 1964; Krebs, 2009). The proportion of
skeletal vs. dental movement is dependent on the rate of expansion and the age of the patient
during treatment (Ciambotti et al., 2001; Cotton, 1978; Hicks, 1978; Krebs, 2009). However,
it is still a common belief that in patients without CLP, SME predominantly leads to more
dentoalveolar than skeletal effects (Lagravère et al., 2005; Pan et al., 2007). In the literature,
some authors have stated that, in order to achieve a skeletal expansion effect in individuals
without CLP, the appliance should produce forces greater than 120 N (Chaconas and Caputo,
1982; Zimring and Isaacson, 1965).

Figure 12. Skeletal and dental effects of RME and SME.
Image from: https://www.slideshare.net/indiandentalacademy/slow-maxillary-
expansion-with-extra-slides-cosmetic-dentistry-courses
34
The Problems that a Patient with CLP Faces

The literature suggests that growth and morphology of the upper arch is adversely affected
by the cleft itself, scar tissue secondary to cleft lip and cleft palate surgeries, and muscle
strain predisposes patients with CLP patients to have a class III malocclusion as a
consequence of the deficient growth in the midface (Abdoney, 1995; Aizenbud et al., 2012;
Al-Gunaid et al., 2008; Bardach, 1990; da Silva Filho et al., 1992; Garib et al., 2014; Isaacson
and Murphy, 1964; Ishikawa et al., 1998; Raju et al., 2014; Ross, 1970; Yang et al., 2012).
As a result, orthodontic expansion is needed in many patients with CLP, as they usually
present with deficiency in the maxillary arch width and alveolar segments that are collapsed
into the cleft space (Aizenbud et al., 2012; da Silva Filho et al., 1992; Garib et al., 2014; Pan
et al., 2007) (Figure 13). Typically, during the ages of 7-13 years, the maxilla is
orthodontically expanded to regain an archform and align the teeth away from the cleft site,
in order to provide an additional amount of space in the cleft region for placement of the bone
graft and thus prepare the maxilla for this procedure (Aizenbud et al., 2012; Vasant, Menon
and Kannan, 2009; Gibson and Shetye, 2017). These patients have their palatal suture
irregular or absent and the alveolar segments are not fused by bone, so the fibrous tissues in
the alveolar cleft are more easily expanded. Usually more expansion is needed in the anterior
than the posterior region, because the alveolar segments are collapsed into the space of the
cleft (Aizenbud et al., 2012; da Silva Filho et al., 1992; Garib et al., 2014). The goal of the
expansion is to regain the arch form and coordinate the transverse dimension of the maxillary
to the mandibular arch, independently of the antero-posterior discrepancy, as the class III
malocclusion will present with relative posterior cross bites. Tooth alignment should be
postponed until the second phase of orthodontic treatment to avoid iatrogenically bringing
the roots out of the bone. The first phase of orthodontic treatment is only to align the
segments.

35

It has been shown that slow expansion leads to a combined orthodontic and orthopedic effect
in patients with CLP (Holberg et al., 2007; Subtelny, 1955; Vasant et al., 2009). In 2007,
Holberg et al. (Holberg et al., 2007) used finite elements analysis (FEA) and found that forces
below 5N are capable of producing a skeletal effect in the midface of patients with CLP due
to their anatomical characteristics. In the 1950’s, Reitan (Reitan, 1951) stated that the
expansion using a Quad-Helix (QH) could generate transverse forces of approximately 5N.
While these forces would not be enough to produce true skeletal effects in patients without
CLP, they would be enough to produce those effects in patients with CLP according to the
findings of Holberg et al.’s study. In other words, the lack of bony continuity between the
cleft segments allows for easier expansion of the segments. Many craniofacial teams perform
SME with QH as their standard of care in patients with CLP (Tindlund et al., 1993). On the
contrary, some authors advocate RME in patients with CLP claiming that it minimizes the
dentoalveolar effects and efficiently produces skeletal effects (Freitas et al., 2012).

Period of Stabilization after Expansion

Regardless of the appliance used, the displaced maxillary segments require a period of
stabilization in order to allow sutural reorganization and stabilization, as well as dissipation
of accumulated residual forces at the contiguous articulations of the maxilla (Hicks, 1978;
Yang et al., 2012). In the patient with cleft lip and palate, this stabilization period consists of
Arch alignment with
anterior expansion
Collapsed into
cleft space
Bone graft
Figure 13: Effect of maxillary expansion to regain the archform in patients with CLP with collapsed
alveolar segments. Once the archform is regained, there will be room for the alveolar bone graft.

36
leaving the expander passively in place for 3-6 months (Yang et al., 2012). During this period
of retention, the teeth tend to upright slightly, as a compensation to the expansion (Hicks,
1978). In his study, Hicks reported that the maxillary segments showed no mean net change
during the stabilization period and stated that the molar angular relationships returned almost
to the pretreatment values, suggesting that the increases in linear arch width observed toward
the end of treatment were due to bodily translation, rather than an increasing rate of facial
tipping of posterior teeth (Hicks, 1978). Cotton observed a similar response in a monkey
maintained in fixed retention (Cotton, 1978). In Hicks’ study, the patients that did not
undergo retention, had lost 45% of the width gain in the first three weeks following expansion
and 69% by the 34th week (Hicks, 1978). Cotton reported that two monkeys that received no
retention showed 16% and 30% of skeletal relapse (Cotton, 1978).

This retention period is particularly important in patients with CLP, because reorganization
of suture is not the only factor causing relapse (Yang et al., 2012). Muscle strain and pressure
of the surrounding musculature, palatal scar contraction, and rotation of bone segments may
be important factors that could cause more relapse compared to patients without clefts,
affecting the long-term stability of the expansion (Isaacson and Murphy, 1964; Yang et al.,
2012). The literature suggests that an insufficient retention period can lead to great or
complete skeletal relapse (Hicks, 1978; Li and Lin, 2007; Nicholson and Plint, 1989;
Robertson and Fish, 1972; Rune et al., 1980; Vlachos, 1996; Yang et al., 2012).

However, both rapid and slow maxillary expanders tend to be relatively bulky and occupy
the whole surface of the palate, interfering with a palatine flap approach for the secondary
alveolar bone graft surgery if the appliance remains in place. If performing the surgery during
the retention period, the surgeon will have to use a buccal surgical approach, which does not
allow full access to the palate and might reduce the success of the surgery. If a palatine access
is desired, the appliance will have to be removed and replaced by a modified transpalatal arch
(TPA) with arms to hold the buccal segments, which will again increase laboratory cost and
require additional visits, or the surgery will have to be postponed until after the retention
period.

37
c. The Programmable NiTi Expander:

A third method of expansion using the NiTi expander (Nickel-Titanium Expander; Ortho
Organizers, Inc., San Marcos, California) has been described to overcome the limitations of
conventional expansion devices, such as the need for patient cooperation, the intermittent
nature of their force application, and the necessity of laboratory work for its production. This
appliance is a type of slow maxillary expander that was first described by Arndt in 1993
(Arndt, 1993). It is temperature-activated and has the ability to produce light, continuous
pressure on the midpalatal suture while simultaneously uprighting, rotating and distalizing
the maxillary molars (Arndt, 1993).

Description of expander (Figure 14):
The NiTi expander is composed of a central 0.040’’ Nickel-Titanium wire in form of a
rounded W (NiTi loop) connected 0.036’’ stainless steel (SS) wire arms that can be adapted
to the dentition (Arndt, 1993; Marzban and Nanda, 1999; Raju et al., 2014). The wire of the
NiTi loop is curved up in the vertical plane as well, to follow the vault of the palate. Between
the SS arms and the NiTi loop there is a NiTi connecting wire that allows differential
expansion. Where the SS arm and the connecting wire come together, there is a connecting
pad with a hook and a rectangular blade that can be inserted in the lingual sheaths spot-
welded to the molar bands.

NiTi loop
Stainless
steel arms
Insertion pad
Connecting
wire
Figure 14: Description of the NiTi expander components: the NiTi loop: 0.040’’. Stainless steel arms:
0.036’’. On the right there is an image of the instructions attached to the appliance. (Nickel-Titanium
Expander; Ortho Organizers, Inc., San Marcos, California)

38
This modified appliance has several advantages compared to the ones that are being used
today:

1. Temperature dependent shape memory: the shape memory and transition temperature
properties of the appliance make frequent activations unnecessary as the expansion
proceeds slowly and continuously until it reaches the programmed limit. The super-
elastic properties of this alloy allows a light continuous force of 180-300g during
expansion (Airoldi et al., 1997; Arndt, 1993; CG et al., 2013; Donohue et al., 2004;
Ferrario et al., 2003; Karaman, 2002; Marzban and Nanda, 1999; Miura et al., 1986;
Raju et al., 2014; Wang et al., 2009). The transition temperature of the NiTi
component of the expander is 94ºF (=34,4ºC) (Arndt, 1993; Marzban and Nanda,
1999; Raju et al., 2014). At temperatures higher than the transition temperature,
interatomic forces bind the atoms more tightly, producing a stiffer metal (Corbett,
1997). On the contrary, at lower temperatures, the forces weaken, making the metal
more flexible (Corbett, 1997). Therefore, cooling down the appliance just before its
insertion allows easy manipulation, because the expander undergoes a martensitic
transformation and becomes super-elastic, allowing an easier cementation (Abdoney,
1995). The expander will return to its original dimension as the temperature rises once
placed in the mouth.

2. Amount of expansion can be predicted: the appliance is processed into a set shape to
which it constantly tends to return after deformation (Arndt, 1993). Because it comes
in different sizes (26-47 mm) (Arndt, 1993), proper appliance size selection will
determine the amount of expansion that each expander can produce, allowing the
clinician to predict the amount of expansion at the time of appliance selection and
delivery (Karaman, 2002).

3. No risk of overexpansion: since the expander is configured to the desired width
depending on the size selected, the activation will end at the final range of the
expander. At this point, the appliance will be passive and there will be no risk of
overexpansion.

39
4. Less number of appointments: frequent visits to the orthodontist are not needed, as
reactivation is not necessary. Therefore, less number of appointments are required.
Prefabrication also eliminates extra appointments as the appliance can be delivered
in one visit and does not require laboratory fabrication (Arndt, 1993; Marzban and
Nanda, 1999; Raju et al., 2014).

5. Non-interference with surgical field: the NiTi expander does not need to be removed
prior to the ABG surgery, as it does not interfere with the surgical field. Thus, the
surgeon can extend a surgical flap to the palate without interference from the
appliance, avoiding the need for a second lingual holding arch appliance to replace a
conventional RME or SME appliance.

6. Cost: prefabrication eliminates the laboratory cost to fabricate and multiple visits to
take impressions and deliver an expander; thus, reducing the overall cost and saving
chair time (Marzban and Nanda, 1999; Raju et al., 2014). Also, the fact that it can be
left in place during the surgery instead of having to be replaced by a transpalatal arch
(TPA) also eliminates the laboratory costs of fabrication of a second appliance. It is
possible to place the expander in one visit without dental impressions.

The expansion rate will vary among patients between 1-3 months depending on the age and
severity of constriction (Marzban and Nanda, 1999).

Different versions of the NiTi expander are in the market and have been used in cleft and
non-cleft patients around the world (Abdoney, 1995; Arndt, 1993; CG et al., 2013; Donohue
et al., 2004; Ferrario et al., 2003; Karaman, 2002; Raju et al., 2014). However, most of the
articles that describe the use of the NiTi expander in patients with CL/P are case reports.
There are only a few controlled studies analyzing the dentoalveolar effects of the NiTi
expander and fewer that compare these effects to those of other appliances, and all of them
have been done in patients without clefts.

Karaman (Karaman, 2002) analyzed the sagittal, vertical and transverse effects of the NiTi
expander in 16 patients without clefts and reported that the crossbites and molar rotations
40
were corrected in all patients, the first molars moved distally, no patient complained about
pain or discomfort, less patient cooperation was needed, the appliance was hygienic and
could be placed chair side without requiring laboratory procedures and that it did not require
patient/parent cooperation for its activation. For all these reasons he concluded that the NiTi
expander could be a good alternative to SME or RME for the treatment of transverse
discrepancies (Karaman, 2002).

In 2001, Ciambotti (Ciambotti et al., 2001) compared the effects of RPE and NiTi expanders
in 25 patients without clefts and concluded that both RPE and NiTi expanders were capable
of expanding the maxillary dentition and the alveolar process and that they were equally
capable of correcting posterior crossbites. They also stated that the radiographic evidence of
suture separation was more obvious in the RPE group and that the NiTi appliance tipped the
molars buccally to a greater extent and caused more distal molar rotation. However,
incomplete details about appliance activation did not really allow to draw definitive
conclusions about the comparison. Donohue et al. 2004 (Donohue et al., 2004) compared
NiTi expander and QH in 33 consecutive patients without clefts and concluded that both
appliances were equally efficient maxillary expanders in terms of magnitude and rate of
expansion, but the NiTi expander produced significantly less discomfort. The cost of the
appliances itself was similar, but while a single appliance was always appropriate to expand
all QH patients, a second appliance was required when a NiTi patient needed more than 6
mm of expansion, thus increasing the cost (Donohue et al., 2004).

The only study that we found in the literature comparing RME and SME in patients with
clefts was the one by Vasant et al. 2009 (Vasant et al., 2009), where no differences were
observed between both expansion modalities. However, their sample was small (n=20, two
groups of 10) and it mixed unilateral with bilateral CLP (Vasant et al., 2009). Furthermore,
the power analysis was not presented and only the changes in the maxillary permanent first
molars were assessed (Vasant et al., 2009).

We were unaware of previous controlled studies analyzing the effects of the NiTi expander
in patients with CL/P and comparing them to other SME or RME appliances in these patients.

41
Aim of the Study:

Currently there is no agreement regarding which type of appliance should be used for the
orthodontic expansion in patients with CLP. Some centers use rapid maxillary expansion,
while others prefer to use slow expansion, typically with a QH appliance (Aizenbud et al.,
2012; Tindlund et al., 1993; Vasant et al., 2009). The lack of scientific literature comparing
the three methods of expansion is the basis for this research.

The goal of the present study is to evaluate the dentoalveolar effects after expansion with the
NiTi expander in patients with complete unilateral cleft lip and palate (UCLP) and compare
them to the effects of RPE and QH.

The null hypothesis (H0) states that there are no differences in the dentoalveolar effects of
among the appliances in terms of transverse measurements, arch length, arch perimeter,
palatal depth, and posterior tipping of maxillary teeth in patients with complete UCLP.

42

3. MATERIAL
AND METHODS

43
a. Sample

This study was approved by the Institutional Review Board (IRB), University of Southern
California (CHLA-14-00262) and its purpose was explained to the patient and guardian.
Verbal and written informed consent and assent were obtained from each participant and
guardian (appendix pages 100-105). Sample size calculation was performed to detect a
minimum difference of 0.5 mm in maxillary width measurements, with a standard deviation
of 0.8 mm at a significance level of 5% with a power of 80%, it was necessary to have a
minimum of 19 subjects in each group.

The sample consisted of patients with complete UCLP, who had expansion before the
secondary alveolar bone graft surgery. The inclusion criteria were:
1. Non-syndromic complete UCLP with history of lip and palate repair performed in
early infancy
2. Initial age 7-14 years
3. Mixed dentition with completely erupted maxillary permanent first molars
4. Presence of collapsed alveolar segments and maxillary constriction with need for
expansion prior to secondary alveolar bone graft surgery
5. No history of previous orthodontic intervention
6. No history of previous bone graft surgery

The study was an intercenter clinical trial between the Children’s Hospital Los Angeles –
University of Southern California (Center 1) and the Hospital for Rehabilitation of
Craniofacial Anomalies of the University of São Paulo in Bauru, Brazil (Center 2) and was
divided in two parts. The first part involved one group of SME with a QH appliance treated
at Center 1 and one group of rapid maxillary expansion (RME) treated at Center 2.

The second part of the study consisted on the addition of a third group of SME with the NiTi
expander after the first part was completed. Thus, the present study will examine the third
group: slow expansion with the NiTi expander, and the results will be compared to the other
two groups.

44
Group 1 (QH): 29 consecutive patients (15 males and 14 females) of Center 1 treated with
SME using a QH appliance (Figure 15). The mean initial age was 10.7 years.

Delivery of the appliance: Bands were adapted on the maxillary permanent first molars for
all patients. Impressions with the bands pinned to fix the bands in the alginate impression
were used to provide a laboratory model for soldering the QH wires to the molar bands. If
the molars were in crossbite, the posterior molars were widened to match the width of the
lower mandibular molars. If the maxillary first molars were not in posterior crossbite as in
most of the cases, then the expanders were widened to provide anterior expansion by pulling
the wire canine loops apart into an over-expanded position. The expanded wire looked like
a W because the quad helix needed enough tension to obtain and maintain the correct
maxillary arch form. The patients were seen six weeks after the delivery of the QH to check
the expansion and evaluate reactivation. If needed, the expander was reactivated by removing
one band, expanding the wire and recementing the loose molar band. The usual time for
expansion was three months.

Group 2 (RPE): 22 consecutive patients (13 males and 9 females) from Center 2 treated
with rapid maxillary expansion with a Hyrax-type expander (Figure 16). The mean initial age
was 9.9 years.

Figure 15. Quad-Helix expander used for expansion of the patients in group 1 in Center 1.
Image from: https://dentagama.com/news/thumb-sucking-appliances
45
Delivery of the appliance: Bands were adapted to the first permanent molars or deciduous
second molars and circumferential clasps bonded to the deciduous canines. The appliance
was activated 1 complete turn a day (approximately 0.8 mm/day) until a slight overcorrection
with the palatal cusps of maxillary first molars in contact with buccal cusps of mandibular
first molars (Ballanti et al., 2010; 2009). The active expansion period varied between 7 and
14 days depending on the severity of arch constriction.

Group 3 (NiTi): 19 consecutive patients (8 males and 11 females) of Center 1 treated with
SME using the NiTi expander. The mean initial age was 9.4 years.

Delivery of the appliance:
1. Fitting bands and welding lingual sheaths: bands should be fitted in the maxillary
first molars the same way as for any appliance (Marzban and Nanda, 1999; Raju et
al., 2014). The molar should be completely erupted to avoid interference of the lingual
sheath with the palatal mucosa. Lingual sheaths should be welded on the palatal side
and should have a hook attached to them to be able to tie the expander to the lingual
sheath with a SS tie and avoid its disinsertion. The best position for the lingual sheaths
to be welded is as occlusal as possible, to avoid any interference from the hook with
the mucosa, which could block a wire loop from engaging the lingual sheath hook.
(Figure 17).
Figure 16. Hyrax-type rapid palatal expander used for expansion of the
patients in group 2 at Center 2.
Image from: http://www.odlortho.com/product-category/expansion/

46

2. Selecting the size of the expander: the sizes that the manufacturer supplies range
from 26mm to 44mm. Marzban and Nanda (Marzban and Nanda, 1999) suggested
measuring the mandibular intermolar width at the central fossae for non-cleft patients
(Figure 18A). However, patients with CLP usually have a flatter palatal vault after
palatal surgery and therefore, a superiorly positioned NiTi wire loop can impinge the
roof of the palate and embed in the palatal tissue. A considerably smaller size of the
expander should be selected so that the expander will flatten as it is widened for
reprogramming. The smaller expander is reshaped in the outstretched position by
reprogramming the NiTi wires with the Bender Soarer-X equipment (Tomy Incor,
Japan) (Figure 18B and C).

Figure 17: Welding lingual sheaths to the bands. Note that the lingual
sheath has been welded as occlusal as possible in the image on the right.
Figure 18: Selecting and reprogramming the NiTi expander. A) Selecting the size, B) Bender Soarer-X equipment
(Tomy Incor, Japan) with two pliers that transmit electric current (1), a panel to adjust the intensity of the current
and heat level (2), and the infrared sensor that allows the current transmission (3). C) Pliers positioned in one of the
NiTi segments and ready to have the electric current transmitted to reprogram the expander.
A B
(1)
(2)
(3)
(4)
C
M
B
47

3. Adapting the SS arms (Figure 19): the SS arms should be adapted to the lateral
segments of the dentition as needed. According to the manufacturer, it is not a
problem if the SS arms do not contact the second bicuspids or second primary molars
at delivery, because as the molars rotate once the expansion starts taking place, they
will contact. If the wire arms need adapting after the expander is inserted, then the
appliance should be removed to check for adequate expansion. If this recheck is not
done, the correction of the SS arms after insertion could make the appliance passive.

4. Reprogramming/activating the NiTi Expander: the expander dimensions can be
individualized for each patient. The NiTi loop wire is held by two bird beak pliers in
the corrected position and then the electric current is applied to wires segment
between the pliers. To reprogram the appliance, the Bender Soarer-X equipment
transmits heat to the NiTi wire loop through electric current. (Figure 18C). The
machine only transmits current to the appliance when the appliance is held by both
pliers above the area of the infrared sensor (Figure 18B). The amount of current and
applied heat level can be adjusted. Setting number 8 is 0.360 V, 0.4 micro Ampere,
is enough to reprogram the expander (Figure 20).
Figure 19: Adapting the SS arms to the lateral segments of the
maxillary dentition using a bird beak plier and a three prong plier.
48

To determine the desired maxillary arch width, the maxillary intermolar and
intercanine widths of the maxillary teeth should be compared to the mandibular model
for arch coordination (Figure 21). In the desired archwidth, the mandibular first
molars central fossae and the center of the buccolingual dimension of the mandibular
canines should match the intermolar distance between the palatal cusp of the
permanent maxillary first molars and the fossae of the permanent maxillary canines.
To reprogram the NiTi expander to the desired width, an additional 3-4 mm will be
added to these measurements for overcorrection to compensate for relapse due to
dental tipping (Donohue et al., 2004; Karaman, 2002; Marzban and Nanda, 1999;
Raju et al., 2014).

Upper intercanine distance = 27 mm Lower intercanine distance = 30 mm
Figure 20: Measuring the intensity of the current of setting number 8 of the Bender Soarer-X equipment
with a digital multimeter.
Figure 21: Measuring the maxillary and mandibular intercanine distance in one of the patients of the study. In
this case the upper intercanine distance is 27 mm and the lower 30 mm, which means that the upper needs to
be increased by 3 mm plus 4 mm of overcorrection, for a total of 7 mm.
49
If the maxillary first molars have an adequate transverse dimension, the expander
should be widened to provide anterior expansion only. Differential expansion to
widen anterior canines more than the posterior molar can be done by a hinge-like
rotation at the central NiTi loop and connecting NiTi wires. If the lingual sheath and
the expander blades do not line up, the NiTi wires need to be twisted slightly and
reprogrammed to adjust for the inclination of the palatal cusps. The Bender Soarer-X
wire reshaper allows the amount of expansion on each area to be customized to each
patient’s needs, enabling differential expansion if desired. Figure 22 compares an
expander before and after reprogrammation to show the difference in the width and
depth of the appliance.

5. Delivering the appliance: the rectangular blades attached to the pads should be
inserted into the lingual sheaths. To facilitate insertion, the NiTi expander can be
cooled down below its transition temperature to increase flexibility (Corbett, 1997;
A
B
Figure 22: Comparison of an expander before reprogrammation (left expander) and after being widened with
the Bender Soarer-X equipment (right expander). A) Note the difference between the width of both expanders
and the shape difference of the NiTi loop. B) Posterior views from NiTi Expander before and after being
reprogrammed, note the flatter configuration of the widened expander on the right image.
50
Karaman, 2002; Marzban and Nanda, 1999; Raju et al., 2014). After both sides are
inserted, the operator needs to check that the expender is not impinging the tissue of
the palate. If the tissue has clearance, the appliance can be tied to the hook of the
lingual sheath with a SS ligature on each side to prevent removal or accidental
dislodging. If the expander is indeed impinging the tissue of the palate, a smaller
expander should be selected and adapted again, to achieve a flatter configuration of
the appliance during reprogramming (Figure 22B).

Once all the above-mentioned steps are completed, the appliance will be active in the mouth.
The expansion will proceed slowly and continuously until it reaches the programmed limit
at the final range of the expander. At this point, the appliance will be passive and there will
be no risk of overexpansion. The expansion rate will vary among patients between 1-3
months depending on the age and severity of constriction (Marzban and Nanda, 1999). To
determine whether the desired width has been achieved, the intercanine and intermolar
distances should be measured again clinically and compared to the goal measurements. If
unsure whether the expander is still active or not, the orthodontist can remove the expander
from the lingual sheaths to check the expansion. When the desired expansion has been
achieved, the patient is referred to the oral or plastic surgeon for the alveolar bone graft
surgery. Marzban and Nanda (Marzban and Nanda, 1999) suggested a retention period of 50-
100% of the expansion time. Because the NiTi expander does not interfere with the surgical
field of the secondary ABG surgery, removal of the appliance is not necessary prior to the
surgery. There is no delay of surgery due to extra appliances.

Treatment sequence

Patients from all groups had lip repair performed at 3-5 months of age and palate repair at
about 12 months of age. Maxillary expansion was performed before secondary alveolar bone
graft surgery. After the active expansion phase, there was a retention period of 6 months
(Ballanti et al., 2009; 2010). The patients underwent the surgical procedure during the
retention period of the expansion, typically at 3 months after the end of the active expansion.
For the NiTi and RPE groups the retention was done by keeping the appliance in place. For
51
the QH group the appliance was replaced by a modified TPA.

Occlusal and dentoalveolar changes were measured in digital models obtained at pre-
expansion (T1) and 6 months post-expansion at the time of appliance removal (T2). The pre
and post expansion plaster models with standard trimming were scanned with a 3Shape R700
3D laser scanner (3Shape A/S, Copenhagen, Denmark).

The image was saved in STL format, compatible with Windows and other specific software
of tridimensional images. All measurements were performed by one investigator of each
center using the software OrthoAnalyzerTM 3D (3Shape A/S, Copenhagen, Denmark).
Comparisons were made within individuals to evaluate the dentoalveolar changes pre- and
post-expansion (T1-T2), as well as between groups.

Figure 23. 3Shape R700 3D laser scanner (3Shape A/S,
Copenhagen, Denmark).
Image from: https://dent247.com/product/3-shape-d1000-scanner/
52
b. Measurements:

Linear measurements: Measured using the OrthoAnalyzer
1. Occlusal transverse dimensions (Figure 24): Measured at the center of the buccal
cusp for the premolars and primary or permanent canines, mesio-buccal cusp of the
primary molars, and center of the grove for the first permanent molars.

2. Cervical transverse dimensions (Figure 24): Measured at the mesio-distal center of
the gingival margin of canines, premolars, primary molars, and permanent first molar.

3. Arch length (AL) (Figure 25): Measured in the horizontal plane from the contact
point between the maxillary central incisors (11.21 point) to a line from the mesial
gingival papilla of the first permanent molar of one side to the other.

4. Arch perimeter (AP) (Figure 25): Circumference of the dental arch. Measured from
the distal surface of the maxillary first permanent molar from one side to the one on
the other side. Divided in 4 segments:
a. Distal of the first molar to mesial of the canine of one side (6-3 = AP1/4)
b. Distal of the lateral to mesial of the central of the same side (2-1 = AP2/4)
Figure 24: Occlusal and cervical transverse dimensions of one patient.

53
c. Mesial of the central to distal of the lateral of the other side (1-2 = AP3/4)
d. Mesial of the canine to distal of the first molar of the other side (3-6 = AP4/4)

5. Palatal depth (Figure 26): Measured from the same line used to measure the arch
length (line from the mesial gingival papilla of the first permanent molar of one side
to the other) to the deepest point of the palate underneath that line.

Figure 25: Arch length and arch perimeter of one patient.

Figure 26: Palatal depth of one patient.
54
Angular measurements: Measured using the OrthoAnalyzer

6. Teeth inclinations: Measured using as reference the occlusal plane passing through
the mesio-buccal cusp tips of the maxillary first molars on both sides, and through
the most mesio-incisal point on the left central incisor (Figure 27 A). The long axis
of the tooth was represented as an arrow at the virtual setup applicative of
OrthoAnalyzer software. On a buccal view of each posterior tooth, this arrow was
positioned in the mesio-distal center of the crown and then angulated to follow the
long axis of the tooth (Figure 27 B). On the distal view of each tooth, the arrow was
bucco-lingually manipulated representing crown torque (Figure 27 C-E), according
to Andrews (Andrews, 1972). The angle between the arrow and the previously
determined occlusal plane was automatically calculated by the software (Figure 27
F). After expansion, increasing values of the angle meant buccal inclination of the
teeth and decreasing values meant lingual inclination of the teeth.

c. Statistical Analysis:

Descriptive statistics and statistical analysis were performed using the RealStats Add-In for
Microsoft Excel 2010. Results were considered significant at p < 0.05.

Normal distribution of the variables was tested with the Shapiro Wilk test. For the variables
following a normal distribution, comparisons within groups (T1 vs. T2) were evaluated with
paired t-tests (two-tail) and intergroup comparisons at T1 and of the changes with a one-way
ANOVA test (two-tail). For the variables that did not follow a normal distribution,
comparisons within groups (T1 vs. T2) were evaluated with the Wilcoxon test (two-tail) and
intergroup comparisons with the Kruskal Wallis test (two-tail).

55

F

D
E
A

B

C

Figure 27. Measurement of the angulation of the teeth to the occlusal plane. A: Definition of the occlusal plane. B: Arrow
representing the long axis of the tooth in a mesio-distal position. C and D: Arrow representing the bucco-lingual angulation of the
tooth. E: arrows representing the angulation of all the 3’s, 5’s and 6’s. F: Angle between the arrow and the occlusal plane.
56

4. RESULTS

57
Table 3 shows no statistically significant differences between the three groups at initial (T1).

Table 3. Comparison of starting values between the groups (ANOVA and Kruskal Wallis)

Table 4 shows expansion changes in the NiTi group. All transverse measurements showed a
statistically significant increase after expansion (Figure 28 and Figure 29). The increase
ranged from 1,21 mm to 6,16 mm and was greater in the canines and premolars than in the
first permanent molars, indicating successful differential expansion. There was also a
statistically significant increase in arch perimeter of 4,89 mm. Arch length and palatal depth
showed no statistically significant change after expansion.

Regarding the inclination of the teeth to the occlusal plane, only the first permanent molars
showed statistically significant differences (-3,49) compared to the initial inclination.
NiTi RPE QH Difference
Mean SD Mean SD Mean SD p
3-3 25,25 3,34 25,42 3,28 23,33 3,96 0,244
3-3' 20,11 2,81 20,95 3,68 18,62 4 0,227
4-4 32,69 4,22 33,76 4,06 32,18 7,58 0,796
4-4' 22,21 3,09 23,63 3,68 22,46 4,08 0,534
5-5 38,96 6,33 39,43 3,34 39,69 5,6 0,92
5-5' 27,73 3,94 28,23 3,96 27,54 5,23 0,883
6-6 44,72 4,44 41,87 4,69 44,42 5,13 0,126
6-6' 34,7 4,53 32,07 4,3 33,9 6,74 0,18
Arch length 21,3 3,01 22 3,44 22,78 3,14 0,267
Arch perimeter 84,39 6,71 84,85 7,39 86,02 7,56 0,806
Palatal depth 10,06 2,21 10,31 3,2 9,69 2,92 0,914
5 inclination 68,66 9,62 67,36 2,11 68,02 1,35 0,904
6 inclination 69,37 8,11 69,71 1,36 67,44 0,96 0,316
58
Table 4. Comparison between pre- and post-expansion within the NiTi group (paired t-test
and Wilcoxon test). T1 = pre-expansion, T2 = 6 months post-expansion.
T1 T2 Change: T2-T1
Variables Mean SD Mean SD Mean SD p value
3-3 25,25 3,34 28,9 3,37 3,65 3,15 0,0021*
3-3' 20,11 2,81 23,26 2,47 3,15 3,14 0,0051*
4-4 32,69 4,22 38,85 2,68 6,16 4,25 0,0001*
4-4' 22,21 3,09 26,31 2,44 4,1 2,8 0,0001*
5-5 38,96 6,33 43,89 4,45 4,93 3,33 0,0003*
5-5' 27,73 3,94 31,31 2,44 3,58 2,81 0,001*
6-6 44,72 4,44 46,6 4,12 1,88 2,14 0,0012*
6-6' 34,7 4,53 35,91 4,42 1,21 2,41 0,0424*
Arch length 21,3 3,01 20,72 3,16 -0,58 1,48 0,105
Arch perimeter 84,39 6,71 89,28 5,86 4,89 2,32 <0,0001*
Palatal depth 10,06 2,21 10,38 2,14 0,32 1,15 0,233
5 inclination 68,66 9,62 72,74 8,31 4,08 9,05 0,056
6 inclination 69,37 8,11 65,88 9,43 -3,49 8,76 0.0189*
* = statistically significant

Below are the before and after records of a patients of the NiTi group (Figure 30 A-G). She
was 10 years and 10 months of age at T1. The anatomy of her maxillary arch clearly illustrates
how more expansion is needed in the anterior than posterior area (Figure 30B).

59

Figure 28. Before and after expansion values within the NiTi group.

Figure 29. Changes within the NiTi group. All variables showed statistically significant
changes from T1 to T2 except arch length, palatal depth, and 5 inclination.

0
10
20
30
40
50
60
70
80
90
100
3-3
3-3'
4-4
4-4'
5-5
5-5'
6-6
6-6'
Arch length
Arch perimeter
Palatal depth
5 inclination
6 inclination
Before and after (NiTi group)
T1
T2
3,65
3,15
6,16
4,1
4,93
3,58
1,88
1,21
-0,58
4,89
0,32
4,08
-3,49
3-3
3-3'
4-4
4-4'
5-5
5-5'
6-6
6-6'
Arch length
Arch perimeter
Palatal depth
5 inclination
6 inclination
Changes within the NiTi group
60

A
B C
D
A
G
E
F
Figure 30. Initial records of a patient of the NiTi group (T1)
A) Extraoral photos: She had a straight profile, slightly deficient maxilla, flat upper lip with an obtuse nasio-
labial angle, and everted lower lip with an acute mento-labial angle. In the frontal view she had deficient incisal
exposure at rest and smile, display of the lower dentition on animation, and an unbalanced smile due to soft tissue
asymmetry. B) Maxillary occlusal photo; C) Mandibular occlusal photo; D&E) Right and left intraoral photos
taken in CR; F) Panoramic x-ray; G) Cephalometric x-ray

61
Figure 31 shows the NiTi expander at delivery, where the deflection of the NiTi loop can be
observed, showing that the appliance was active. After 2 months, the appliance had reached
the programmed dimension and had expanded the maxillary arch to ideal position based on
her intraoral and cast measurements (Figure 31 B). At the end of expansion morphology of
the NiTi loop appeared less deflected, showing that the appliance had reached a passive
configuration (Figure 31 B). The patient underwent the alveolar bone graft surgery after
expansion, during the retention period. T2 records were taken 6 months after the end of
expansion upon appliance removal (Figure 32 A-F).

A
B
Figure 31. NiTi Expander in place.
A) Intraoral photo at delivery. Note the deflection of the NiTi loop that shows that the
appliance is active. B) Intraoral photo at the end of expansion. Note the difference in
the morphology of the NiTi loop compared to the delivery photo.
62

Figure 32. Final records of a patient of the NiTi group (T2: 6 post-expansion)
A) Extraoral photos; B) Maxillary occlusal photo: note the maxillary left permanent canine erupting into the
area of the cleft; C) Mandibular occlusal photo; D-F) Right, left and central intraoral photo taken in CR.

A
B C
D
E F
63
Table 5, Figure 33, and Figure 34 show expansion changes in the QH group. All transverse
dimensions (except 4-4) showed a statistically significant increase after expansion. The
increase ranged from 2,05 mm to 4,08 mm and was greater in the canine than molar area,
indicating successful differential expansion. Arch perimeter also increased significantly 2,63
mm after expansion. Arch length and palatal depth did not show any statistically significant
changes after expansion. There was a statistically significant increase of 3,49º in the buccal
inclination of the second premolars / second primary molars, but no significant change in the
buccal inclination of the first permanent molars.

Table 5. Comparison between pre- and post-expansion within the QH group (paired t-test
and Wilcoxon test). T1 = pre-expansion, T2 = 6 months post-expansion.
* = statistically significant
QH T1 QH T2 Change: T2-T1
Variables Mean SD Mean SD Mean SD p value
3-3 23,33 3,96 27,41 5,84 4,08 4,15
0,004*
3-3' 18,62 4 22,38 4,83 3,76 2,83 <0,001*
4-4 32,18 7,58 35,65 4,76 3,47 5,89 0,016
4-4' 22,46 4,08 24,51 3,66 2,05 3,77 0,029*
5-5 39,69 5,6 42,59 4,35 2,9 3,81 <0,001*
5-5' 27,54 5,23 29,84 4,07 2,3 3,51 0,001*
6-6 44,42 5,13 46,9 4,04 2,48 3,08 <0,001*
6-6' 33,9 6,74 36,52 4,45 2,62 4,18 0,005*
Arch length 22,78 3,14 21,86 4,04 -0,92 3,53 0,171
Arch perimeter 86,02 7,56 88,65 7,66 2,63 5,71 0,019*
Palatal depth 9,69 2,92 9,49 3,11 -0,2 2,49 0,681
5 inclination 68,02 1,35 71,51 1,49 3,49 1,26 0,010*
6 inclination 67,44 0,96 69,4 1,16 1,96 1,19 0,16
QH T1 QH T2 Change: T2-T1
Variables Mean SD Mean SD Mean SD p value
3-3 23,33 3,96 27,41 5,84 4,08 4,15
0,004*
3-3' 18,62 4 22,38 4,83 3,76 2,83 <0,001*
4-4 32,18 7,58 35,65 4,76 3,47 5,89 0,016
4-4' 22,46 4,08 24,51 3,66 2,05 3,77 0,029*
5-5 39,69 5,6 42,59 4,35 2,9 3,81 <0,001*
5-5' 27,54 5,23 29,84 4,07 2,3 3,51 0,001*
6-6 44,42 5,13 46,9 4,04 2,48 3,08 <0,001*
6-6' 33,9 6,74 36,52 4,45 2,62 4,18 0,005*
Arch length 22,78 3,14 21,86 4,04 -0,92 3,53 0,171
Arch perimeter 86,02 7,56 88,65 7,66 2,63 5,71 0,019*
Palatal depth 9,69 2,92 9,49 3,11 -0,2 2,49 0,681
5 inclination 68,02 1,35 71,51 1,49 3,49 1,26 0,010*
6 inclination 67,44 0,96 69,4 1,16 1,96 1,19 0,16
64

Figure 33. Before and after expansion values within the QH group.

Figure 34. Changes within the QH group. All variables showed statistically significant
changes from T1 to T2 except 4-4, arch length, palatal depth, and inclination of the first
molars.
0
10
20
30
40
50
60
70
80
90
100
3-3
3-3'
4-4
4-4'
5-5
5-5'
6-6
6-6'
Arch length
Arch perimeter
Palatal depth
5 inclination
6 inclination
Before and after (QH group)
T1
T2
4,08
3,76
3,47
2,05
2,9
2,3
2,48
2,62
-0,92
2,63
-0,2
3,49
1,96
3-3
3-3'
4-4
4-4'
5-5
5-5'
6-6
6-6'
Arch length
Arch perimeter
Palatal depth
5 inclination
6 inclination
Changes within the QH group
65
Table 6, Figure 35, and Figure 36 show expansion changes in the RPE group. All transverse
dimensions significantly increased after expansion. The increase in width ranged from 4,82
to 6,81 mm and was even in the anterior and posterior area, indicating a parallel type of
expansion. With expansion, arch perimeter significantly increased 6.08mm, while arch length
and palatal depth significantly decreased. The decrease for arch length was of 0.91 mm and
for palatal depth 1.18mm. A statistically significant increase in buccal tipping was observed
for the second premolars / second primary molars (+ 6,64º), as well as for the first permanent
molars (+ 4,39º).

Table 6. Comparison between pre- and post-expansion within the RME group (paired t-test
and Wilcoxon test). T1 = pre-expansion, T2 = 6 months post-expansion.
* = statistically significant
RME T1 RME T2 Change: T2-T1
Variables Mean SD Mean SD Mean SD p value
3-3 25,42 3,28 30,84 3,67 5,42 3,71 <0,001*
3-3' 20,95 3,68 25,77 4,17 4,82 3,65 <0,001*
4-4 33,76 4,06 40,57 4,3 6,81 4,68 <0,001*
4-4' 23,63 3,68 29,37 3,51 5,74 4,18 <0,001*
5-5 39,43 3,34 46 3,98 6,57 2,78 <0,001*
5-5' 28,23 3,96 33,52 3,82 5,29 3,46 <0,001*
6-6 41,87 4,69 47,58 3,84 5,71 3,77 <0,001*
6-6' 32,07 4,3 37,71 3,63 5,64 3,15 <0,001*
Arch length 22 3,44 21,09 2,98 -0,91 1,33 0,004*
Arch perimeter 84,85 7,39 90,93 7,08 6,08 5,79 <0,001*
Palatal depth 10,31 3,2 9,13 3,76 -1,18 1,78 0,005*
5 inclination 67,36 2,11 74 2,18 6,64 2,09 0,011*
6 inclination 69,71 1,36 74,1 1,06 4,39 0,92 <0,001*
66

Figure 35. Before and after expansion values within the RPE group.

Figure 36. Changes within the RPE group. All variables showed statistically significant
changes from T1 to T2.
0
10
20
30
40
50
60
70
80
90
100
3-3
3-3'
4-4
4-4'
5-5
5-5'
6-6
6-6'
Arch length
Arch perimeter
Palatal depth
5 inclination
6 inclination
Before and after (RPE group)
T1
T2
5,42
4,82
6,81
5,74
6,57
5,29
5,71
5,64
-0,91
6,08
-1,18
6,64
4,39
3-3
3-3'
4-4
4-4'
5-5
5-5'
6-6
6-6'
Arch length
Arch perimeter
Palatal depth
5 inclination
6 inclination
Changes within the RPE group
67
Table 7. Comparison of the treatment changes between the three groups (ANOVA and
Kruskal Wallis).

NiTi RPE QH Difference
Mean SD Mean SD Mean SD p
Which
groups?
3-3 3,64 3,15 5,42 3,71 4,08 4,15 0,201
3-3' 3,15 3,14 4,81 3,65 3,76 2,83 0,132
4-4 6,16 4,25 6,81 4,68 3,47 5,89 0,035* All groups
4-4' 4,1 2,8 5,74 4,18 2,06 3,77 0,0051* All groups
5-5 4,93 3,33 6,56 2,78 2,9 3,81 0,0015* All groups
5-5' 3,57 2,81 5,29 3,46 2,3 3,51 0,0009* All groups
6-6 1,88 2,14 5,71 3,77 2,48 3,08 0,0006* All groups
6-6' 1,21 2,41 5,64 3,15 2,63 4,18 <0,0001* All groups
Arch length -0,58 1,48 -0,9 1,33 -0,92 3,53 0,5295
Arch perimeter 4,88 2,32 6,07 5,79 2,64 5,71 0,014* All groups
Palatal depth 0,33 1,15 -1,18 1,78 -0,2 2,49 0,058
5 inclination 4,09 9,05 6,64 2,09 3,49 1,26 0,254
6 inclination -3,49 8,76 4,39 0,92 1,96 1,19 <0,0001* All groups
* = statistically significant

68

Figure 37. Comparison of the changes between groups. Statistically significant differences in all the variables
except 3-3, 3-3’, arch length, palatal depth and 5 inclination.

Table 7 and Figure 37 show the expansion changes between the three groups. All transverse
measurements except the canines showed statistically significant differences between the
groups. Post-hoc tests revealed that the differences were between all the groups. For both
SME groups (NiTi and QH) the expansion changes seemed to be greater anteriorly than
posteriorly. The changes ranged from 1,21mm to 6,16mm in the NiTi group and from 2,3mm
to 4,08mm in the QH group, with the smallest values registered for the first permanent molar:
6-6 = 1,88mm (NiTi) and 2,48mm (QH) and 6-6’ = 1,21mm (NiTi) and 2,62mm (QH). On
the other hand, the changes in the RPE group were similar in the anterior and posterior teeth,
resulting in a more parallel expansion (Figure 38 and Figure 39).

-4
-2
0
2
4
6
8
3-3
3-3'
4-4
4-4'
5-5
5-5'
6-6
6-6'
Arch length
Arch perimeter
Palatal depth
5 inclination
6 inclination
Comparison of changes between groups (T2-T1)
NiTi
RPE
QH
69

Figure 38. Comparison of the width changes between groups at the occlusal. Statistically significant
differences between all variables except 3-3.

Figure 39. Comparison of the width changes between groups at the gingival margin. Statistically significant
differences between the groups for all variables except 3-3’.

0
1
2
3
4
5
6
7
8
3-3 4-4 5-5 6-6
Changes in width at occlusal
NiTi
RPE
QH
0
1
2
3
4
5
6
7
3-3' 4-4' 5-5' 6-6'
Changes in width at cervical
NiTi
RPE
QH
70
Arch perimeter showed significantly greater increases in the RPE group (6,08 mm), followed
by the NiTi group (4,89 mm) and had the smallest increase in the QH group (2,63mm) (Figure
40 and Figure 41).

Figure 40. Arch perimeter before and after expansion for all groups. Statistically significant differences between
all groups.

Figure 41. Comparison of the net changes in arch perimeter. Statistically significant differences between all the
groups.
80
82
84
86
88
90
92
NiTi RPE QH
Arch perimeter before and after expansion
T1
T2
4,88
6,07
2,64
NiTi RPE QH
Arch perimeter
Changes in arch perimeter (T2-T1)
71
Finally, the inclination of the first molars (buccal tipping) changed in different directions
between groups (Figure 42 and Figure 43): the NiTi group showed a statistically significant
decrease of -3,49º (crowns tipped lingually), while the RPE and QH showed a statistically
significant increase (crowns tipped buccally). The increase was greater in the RPE group
(+4,39º) than in the QH group (+1,96º). No statistically significant differences were found
between the groups for changes in the intercanine width (3-3 and 3-3’), arch length, palatal
depth and buccal tipping of the second premolar / second primary molar.

Figure 42. First molar inclination (buccal tipping) before and after expansion for all groups. Statistically
significant differences between all groups.

60
62
64
66
68
70
72
74
76
NiTi RPE QH
Buccal tipping of the first molar before and after
expansion
T1
T2
72

Figure 43. Comparison of the net changes in first molar inclination to the occlusal plane (buccal tipping).
Statistically significant differences between all the groups.

Complications

Complications of the NiTi Expander occurred in 10% of the patients and included detachment
of the lingual sheath, wire breakage, non-activation if the SS arms were considerably
readapted after reprogramming the appliance, and wire embedment into the palatal tissue if
the expander size was too large to begin with (Figure 44). As mentioned above, to avoid wire
embedment it is important to select a small size of the expander and reprogram it to a wider
and flatter configuration.
Changes in first molar inclination to the occlusal plane
buccal tipping (T2-T1)
-3,49
4,39
1,96
NiTi RPE QH
Changes in 6 inclination
73

Figure 44. Complication: wire embedment in the palatal tissue of an oversized expander.

74

5. DISCUSSION

75

The present study analyzed the effects of a NiTi expander on the dental and palatal structures
of patients of 7-14 years of age with complete UCLP and compared them to the effects of
RPE and QH.

Sample:

Although the patients of both centers underwent early surgeries at approximately the same
stages of development, the patients were treated by different surgical teams, which could
have led to differences in the initial severity of the maxillary arch deformity. However, there
were no statistically significant differences between the groups at the initial time point (T1)
(Table 3).

The first phase of the study had one experimental group per center and the sample was
selected via consecutive cases that met the same inclusion criteria in both centers. Since there
was only one group per center at that point, randomization of the sample was not necessary.
Once the first phase of the study was completed, the NiTi group was added and the cases
were selected consecutively as well. This study does not have a control group, as it would be
unethical not to treat or to delay treatment of a group of patients.

Clinical Manipulation of the Appliances

The reprogrammed NiTi expander demonstrated several manipulation advantages compared
to the RPE and QH and overcame some limitations of the regular not-reprogrammed NiTi
expander. Expansion did not take longer with the NiTi than with QH, reflecting a similar
expansion rate for both SME appliances, in agreement with the findings of Donohue et al.
2004 (Donohue et al., 2004), who compared NiTi expander to QH in 33 patients without CLP
and concluded that both appliances were equally efficient maxillary expanders in terms of
magnitude and rate of expansion.

76
The NiTi expander allowed appliance delivery in one visit, as it did not require laboratory
configuration, thus reducing laboratory cost and chair time, therefore increasing clinical
efficiency, which indirectly also reduced the cost. Its temperature dependent shape memory
resulted in a slow and continuous expansion and eliminated the need for reactivations, thus
reducing the number of visits. On the contrary, the QH had to be removed and re-cemented
for its reactivation, thus increasing the chair time and number of visits of the patients. Finally,
the RPE had to be activated daily by the patient’s parent, which can lead to complications
such as lost keys or incomplete turns. These findings agree with what was reported by
Karaman in 2002 (Karaman, 2002), who reported successful expansion results with NiTi
expanders in 16 patients without CLP and concluded that NiTi expanders required less patient
cooperation than other appliances, could be placed chair side without requiring laboratory
procedures and did not require patient/parent cooperation for its activation as opposed to
other RME and SME appliances (Karaman, 2002).

Reprogramming the expander allowed precise expansion customization as each appliance
was preprogrammed to the desired width of each patient. This is a great advantage over the
QH, where the activation is done by hand and the exact millimeters of expansion are usually
hard to predict. Additionally, reprogramming the expander to the desired final width
eliminates the risk of overexpansion, as the activation will end at the final range of the
expander and the appliance will be passive once it reaches that dimension. For the QH it is
always difficult to know if it is still active without decementing it from the dentition.

Furthermore, being able to reprogram the expander also allowed us to reduce our inventory,
as one small size of the appliance can be reshaped with the Bender Soarer-X machine to
almost any desired width. Contrary to what Karaman (Karaman, 2002) stated, instead of
proper appliance size selection, now it is proper appliance reprogramming that will determine
the amount of expansion that each expander can produce, allowing the clinician to predict
the amount of expansion at the time of appliance customization and delivery. Additionally,
reprogramming the expander also eliminates the need to replace the appliance with a bigger
one when a great amount of expansion is needed, which has been reported as a cost and
efficiency disadvantage before, as some authors had to use multiple NiTi expanders for one
patient (Abdoney, 1995; Donohue et al., 2004). Donohue et al. (Donohue et al., 2004)
77
compared QH and NiTi expanders and stated that the cost of the appliances itself was similar,
but while a single appliance was always appropriate to expand all QH patients, a second
appliance was required when a NiTi patient needed more than 6 mm of expansion, thus
increasing the cost. However, our study overcomes this disadvantage by reprogramming the
NiTi expander with the Bender Soarer-X machine. On the other hand, it does require the
initial purchase of the machine, which increases the initial cost, but decreases the cost in the
long run by reducing the number of appointments, clinician chair time and laboratory cost.

Finally, its non-interference with surgical field is a great advantage for patients with CLP, as
it does not need to be removed prior to the ABG surgery, because it does not interfere with
the surgical field and allows a palatine access to the cleft site while still in place. On the
contrary, RPE and QH interfere with the surgical field and cannot stay in place during
surgery. Regardless of the appliance used, the displaced maxillary segments require a period
of stabilization, which usually consists on leaving the expander passively in place for 3-6
months (Yang et al., 2012), in order to allow sutural reorganization and stabilization, as well
as dissipation of accumulated residual forces at the contiguous articulations of the maxilla
(Hicks, 1978; Yang et al., 2012). This retention period is particularly important in patients
with CLP, because reorganization of suture is not the only factor causing relapse (Yang et
al., 2012). Muscle strain and pressure of the surrounding musculature, palatal scar
contraction, and rotation of bone segments may be important factors that could cause more
relapse compared to patients without clefts, affecting the long-term stability of the expansion
(Isaacson and Murphy, 1964; Yang et al., 2012). Since the RPE and QH interfere with the
surgical field of the ABG, they will have to be replaced by a modified TPA with arms to hold
the buccal segments, which will again increase laboratory cost and require additional visits,
or the surgery will have to be postponed until after the retention period. However, delaying
the surgery could compromise the success of the graft, as timing and close coordination with
the canine eruption is a critical factor to ensure greater success of the alveolar bone graft
(Bergland et al., 1986; Enemark et al., 1987; Freihofer et al., 1993; Gibson and Shetye, 2017;
Meyer and Mølsted, 2013; Newlands, 2000; Turvey et al., 1984)

78
Digital Models:

The models were digitized and analyzed in the computer, as previous studies have shown
that linear measurements of arch width and length on digital models are highly accurate and
reproducible (Bell et al., 2014; Reuschl et al., 2016; Sousa et al., 2012). In this study, digital
models allowed us to perform not only linear, but also angular measurements, which have
not been easy to perform in traditional stone models (Ciambotti et al., 2001). Furthermore, it
has allowed us to determine reference planes to standardize our measurements and has
facilitated calibration between both centers.

Dentoalveolar Effects

All three appliances (NiTi, RPE and QH) successfully expanded the dentoalveolar segments
in the present study. All transverse measurements showed a statistically significant increase
compared to the initial values within each group. These findings agree with Vasant et al.
(Vasant et al., 2009), who reported successful expansion results with QH and RPE in patients
with CLP, as well as with Ciambotti et al. (Ciambotti et al., 2001), who compared the effects
of RPE and NiTi expanders in 25 patients without CLP and concluded that both RPE and
NiTi expanders were capable of expanding the maxillary dentition and the alveolar process
and that they were equally capable of correcting posterior crossbites.

When comparing between the groups, the expansion was similar in the canine area for all
groups (no statistically significant differences between the groups) with p = 0,201 and p =
0,132 for 3-3 and 3-3’ respectively. However, the changes for all the other width
measurements showed statistically significant differences between all the groups. The NiTi
and QH were capable of producing differential expansion with greater changes anteriorly
than posteriorly, ranging from 1,21mm to 6,16mm in the NiTi group and from 2,3mm to
4,08mm in the QH group, with the smallest values registered for the first permanent molar:
6-6 = 1,88mm (NiTi) and 2,48mm (QH) and 6-6’ = 1,21mm (NiTi) and 2,62mm (QH) (Table
7).The NiTi showed more differential expansion than the QH, which could be due to greater
individual expansion needs in the NiTi group. It could also be explained by a possibly higher
79
relapse potential of the QH during the retention phase, since this appliance has to be replaced
by a modified TPA to be able to have palatine surgical access for the alveolar bone graft
surgery, while the NiTi remained in place since T1 until T2. However, whether the NiTi
expander or a modified TPA prevents relapse better is unknown and cannot be assumed based
on the results of this study. On the other hand, the changes in the RPE group were similar in
the anterior and posterior areas and ranged from 4,81 mm to 6,81 mm, indicating a more
parallel expansion and resulting in over-expanded posterior segments. Similar results were
found on a previous study by Ayub et el. (Ayub et al., 2016), where arch width increases
ranged from 3.92 to 5.97 mm after RME with a Haas-type expander in patients with UCLP.
Further studies have also shown similar findings (Figueiredo et al., 2014; Gautam et al., 2011;
Holberg et al., 2007; Pan et al., 2007). This is important, because patients with UCLP usually
present with collapsed dentoalveolar segments that have greater constrictions in the anterior
than posterior area and therefore require differential expansion (Aizenbud et al., 2012;
Bardach, 1990; da Silva Filho et al., 1992; Garib et al., 2014; Ross, 1970). In fact, the first
molars are not often in crossbite in most cases with cleft lip and palate, but to achieve
sufficient anterior expansion and create enough access for the bone graft procedure, a large
and sometimes unnecessary posterior expansion must be attained with RMEs (Aizenbud et
al., 2012). In an effort to solve this problem, Garib et al. (Garib et al., 2014) suggested a
modified design of a RME appliance to provide differential opening. Excessive widening of
the posterior cleft area can negatively impact proper surgical closure, as it adds stress to the
tissues that will cover the bone graft (Aizenbud et al., 2000). Furthermore, it can also result
in occlusal disharmony from buccal crossbite and cause the development of otitis media
(Aizenbud et al., 2000). Despite this disadvantage of RME, some authors still advocate this
type of expansion in patients with CL/P claiming that it minimizes the dentoalveolar effects
and efficiently produces skeletal effects (Freitas et al., 2012). It is still a common belief that
SME predominantly leads to more dentoalveolar than skeletal effects in patients without
clefts (Lagravère et al., 2005; Pan et al., 2007). However, SME has been shown to produce a
combined orthodontic and orthopedic effect in patients with CL/P due to their anatomical
characteristics (Holberg et al., 2007; Subtelny, 1955; Vasant et al., 2009). The proportion
between skeletal and dental expansion effects could not be determined in the present study
because we only evaluated dental models. Nevertheless, according to the literature, we can
assume that both SME and RME appliances have combined skeletal and dentoalveolar effects
80
in patients with CL/P and therefore, that the expansion in our study was a combination of
both.

Arch perimeter also showed statistically significant increases in all groups as a consequence
of regaining the archform of the maxillary arch, as well as the increase in the maxillary width.
There were statistically significant differences between the three groups (p = 0,014), with
greater increases in the RPE group (6,08 mm), followed by the NiTi group (4,89 mm) and
then the QH group (2,63mm). The greater arch perimeter increases of the RPE group
compared to the SME groups could be explained by the overexpansion of the posterior
segments, since that was not present in the other two groups and might have added additional
arch perimeter millimeters. Similar effects of RME and SME in arch perimeter pattern have
been previously described in patients with (Ayub et al., 2016; de Medeiros Alves et al., 2016;
Figueiredo et al., 2014; Vasant et al., 2009) and without oral clefts (Adkins et al., 1990;
Akkaya et al., 1998; Wong et al., 2011). The differences between the QH and NiTi groups
could be due to the same reasons mentioned above: greater individual expansion needs in the
NiTi group and a possibly higher relapse potential of the QH during the retention phase.
Arch length and palatal depth showed no statistically significant changes before and after
expansion within the SME groups, which agrees with what Medeiros Alves et al. found in
their study after SME with QH in patients with bilateral cleft lip and palate (BCLP) (de
Medeiros Alves et al., 2016). Ferrario et al. (Ferrario et al., 2003) also observed no changes
in palatal depth after expansion with the NiTi expander in patients without clefts. On the
contrary, both arch length and palatal depth significantly decreased 0,91 mm (p = 0,004) and
1,18 mm (p = 0,005) respectively within the RME group. The arch length decrease might be
explained by a slight posterior displacement of the anterior maxillary alveolar segment due
to the tension of scar tissue of the operated lip (Adkins et al., 1990; Haas, 1965; Habeeb et
al., 2013). This posterior displacement could have affected the arch length measurements,
because one of the reference points that we used (11.21 point) is located between the
maxillary central incisors (Figure 25). This posterior displacement would be expected to
occur in all three groups. However, the QH and NiTi expander have been shown to have a
distal rotation effect in the anchor teeth (Arndt, 1993; Ciambotti et al., 2001; Ferrario et al.,
2003; Henry, 1993; Karaman, 2002; Vasant et al., 2009), which has not been reported in
81
RME appliances due to their rigidity (Vasant et al., 2009). This posterior rotation might have
slightly increased the arch length in these groups (Corbett, 1997; Ferrario et al., 2003) and
thus accounted for the decrease secondary to the posterior displacement of the anterior
maxillary alveolar segment, resulting in no net change for the arch length in the SME groups.
Another explanation could be that the posterior displacement of the anterior maxillary
segment could have been greater in the RPE group due to a higher stress induced by the
appliance compared to a more physiological process in the SME groups (Ciambotti et al.,
2001; Storey, 1973). Similar results were found in a previous study in patients with UCLP,
where arch length decreased 1,06 mm after RME with a Haas-type expander (Ayub et al.,
2016); and in a study in patients with BCLP, where a significant arch length decrease was
also reported after RME with a Hyrax-type expander (de Medeiros Alves et al., 2016).

The decrease in palatal depth after RME disagrees with the findings of Ayub et al. where no
changes were observed in palatal depth after RME in patients with UCLP (Ayub et al., 2016).
However, these differences in the findings might be due to appliance design: in our study we
used a Hyrax-type expander, while Ayub et al. used a Haas-type expander. The palatal acrylic
of the Haas expander might have prevented changes in the palatal depth in the study by Ayub
et al. Other studies in patients without clefts have also found contradicting results. Some
authors reported a decrease in palatal depth after expansion (Wertz and Dreskin, 1977), while
others did not find any changes (Davis and Kronman, 1969). However, the patients of Wertz
and Dreskin’s study were expanded with a variety of fixed expansion appliances (Wertz and
Dreskin, 1977) and Davis and Kronman did not give details about the design of the expanders
that they used (Davis and Kronman, 1969).

However, when analyzing the change in arch length and palatal depth values between the
groups, ANOVA showed no statistically significant differences between them (p = 0,53 and
p = 0,06 respectively).

Buccal tipping (inclination) of the posterior teeth varied between teeth and groups. While the
inclination of the second premolar or second primary molar showed no statistically
significant changes within the NiTi group, it did significantly increase within the QH group
(+3,49º). This could be due to the fact that some patients had the QH banded in the 5’s when
82
the first molars were not completely erupted, and buccal tipping of anchorage teeth has been
observed in previous studies in patients with and without CLP (Aizenbud et al., 2012;
Brunetto et al., 2013; de Medeiros Alves et al., 2016; Holberg et al., 2007). The RPE group
also showed a significant increase in buccal tipping after expansion (+6,64º). This increase
might be indicating the dental component of the expansion with RME, which has also been
reported in previous studies of expansion in patients with and without CLP (Ayub et al.,
2016; Brunetto et al., 2013; de Medeiros Alves et al., 2016; Figueiredo et al., 2014; Pan et
al., 2007). However, the comparison among the expander groups showed no statistically
significant difference between them (p = 0,254), which agrees with previous findings (de
Medeiros Alves et al., 2016; Vasant et al., 2009).

The first molars changed in different directions in each group: the NiTi group showed a
statistically significant decrease (-3,49º), meaning that the first molars tipped lingually 3,49º.
This could be explained by the ability of torqueing the insertion pad of the NiTi expander
with the Bender-Soarer-X machine to counteract the buccal tipping effect during expansion.
Our study shows that by reprogramming the NiTi expander to a configuration with lingual
crown torque added to the insertion pad (that will be inserted into the lingual sheath of the
maxillary first molar), the buccal tipping of the anchor teeth can be counteracted and
prevented, thus minimizing the compensation of the teeth, which might maximize the true
expansion effect. The QH group showed a slight increase in buccal tipping (+1,96º), but it
was not statistically significant (p = 0,16), probably because not all patients had the QH
banded on the first molars. These findings are in agreement with Hicks, who stated that in
the period of retention, the teeth tend to upright slightly, as a compensation to the expansion
(Hicks, 1978). In his study, he reported that the maxillary segments showed no mean net
change during the stabilization period and stated that the molar angular relationships returned
almost to the pretreatment values, suggesting that the increases in linear arch width observed
toward the end of treatment were due to bodily translation, rather than an increasing rate of
facial tipping of posterior teeth (Hicks, 1978). Cotton observed a similar response in a
monkey maintained in fixed retention (Cotton, 1978). Finally, the RPE showed the greatest
buccal tipping effect with a statistically significant increase of 4,39º, again indicating the
dental component of the expansion with RME. The greater buccal tipping effect could be
because this group also showed the greatest expansion effects in the first molar area, which
83
probably led to greater compensation and side effects. Our study disagrees with the findings
of other RME studies in patients with UCLP and BCLP (de Medeiros Alves et al., 2016;
Vasant et al., 2009), and agrees with the findings of Brunetto et al. (Brunetto et al., 2013) in
patients without clefts.

Our findings also disagree with Ciambotti et al. (Ciambotti et al., 2001), who compared the
effects of RPE and NiTi expanders in 25 patients without clefts and concluded that the NiTi
expander tipped the molars buccally to a greater extent. However, their study was done in
patients without clefts and they also stated that the radiographic evidence of suture separation
was more obvious in the RPE group, which together with the greater molar tipping of the
NiTi group might suggest that the NiTi expander had a greater dentoalveolar effect than the
RPE. Their findings for the NiTi expander are not surprising for patients without clefts, since
the literature suggests that in order to achieve a skeletal expansion effect, the appliance
should produce forces greater than 120N (Chaconas and Caputo, 1982; Zimring and Isaacson,
1965) and SME appliances have been shown to generate transverse forces of approximately
5N, which would not be enough to produce true skeletal effects in patients without clefts
(Reitan, 1951). However, in patients with CLP, forces below 5N have been shown capable
of producing skeletal effects due to their anatomical characteristics (Holberg et al., 2007),
which might explain the reason of our findings for less buccal tipping in the SME groups
compared to Ciambotti’s findings. Other authors have also stated that transverse skeletal
resistance is reduced in patients with CLP due to the irregular or absent palatal suture (Levitt
et al., 1999; Tindlund and Rygh, 1993). Nevertheless, incomplete details about appliance
activation in Ciambotti’s study does not really allow to draw definitive conclusions about
this comparison.

84

6. CONCLUSIONS

85
1. All three expanders can widen the maxillary arch in patients with complete UCLP.

2. The QH and programmable NiTi expander did not over-expand the posterior
segments of the maxillary arch.

3. The NiTi expander maintained the bucco-lingual torque because the torque can be
programmed into the wire.

4. The programmable NiTi expander can expand the maxilla comparably with RPE and
Quad Helix with fewer visits and cost.

5. The Bender Soarer-X technology gives the operator the freedom of customizing the
expansion to each patient’s needs.

6. Given its shape memory and ability to be reprogrammed, the amount of expansion
can be predicted, frequent activations are unnecessary, and it does not rely on patient
cooperation.

7. The non-interference with the surgical field avoids the need of expander removal
prior to undergoing the alveolar bone graft surgery, allowing a longer retention period
without having to delay the surgery or to replace the expander with a modified TPA
prior to surgery.

8. Its lower cost and reduction in laboratory fees make the NiTi expander a very
affordable alternative to other expansion modalities.

9. For all these reasons, the NiTi expander is a great appliance to provide expansion
prior to alveolar bone graft surgery in patients with complete UCLP, as it adapts to
their needs and should be considered the appliance of choice for the treatment of these
patients.

86

7. REFERENCES

87
Abdoney, M.O. (1995). Use of the Arndt nickel titanium palatal expander in cleft palate
cases. J Clin Orthod 29, 496–499.
Adkins, M.D., Nanda, R.S., and Currier, G.F. (1990). Arch perimeter changes on rapid palatal
expansion. American Journal of Orthodontics and Dentofacial Orthopedics 97, 194–199.
Airoldi, G., Riva, G., Vanelli, M., Filippi, V., and Garattini, G. (1997). Oral environment
temperature changes induced by cold/hot liquid intake. American Journal of Orthodontics
and Dentofacial Orthopedics 112, 58–63.
Aizenbud, D., Hefer, T., Rachmiel, A., Figueroa, A.A., Joachims, H.Z., and Laufer, D.
(2000). A possible otological complication due to maxillary expansion in a cleft lip and palate
patient. Cleft Palate Craniofac. J. 37, 416–420.
Aizenbud, D., Ciceu, C., Rachmiel, A., and Hazan-Molina, H. (2012). Reverse quad helix
appliance: differential anterior maxillary expansion of the cleft area before bone grafting. J
Craniofac Surg 23, e440–e443.
Akcam, M.O., Evirgen, S., Uslu, O., and Memikoğlu, U.T. (2010). Dental anomalies in
individuals with cleft lip and/or palate. Eur J Orthod 32, 207–213.
Akkaya, S., Lorenzon, S., and Uçem, T.T. (1998). Comparison of dental arch and arch
perimeter changes between bonded rapid and slow maxillary expansion procedures. The
European Journal of Orthodontics 20, 255–261.
Al-Ghatam, R., Jones, T.E.M., Ireland, A.J., Atack, N.E., Chawla, O., Deacon, S., Albery,
L., Cobb, A.R.M., Cadogan, J., Leary, S., et al. (2015). Structural outcomes in the Cleft Care
UK study. Part 2: dento-facial outcomes. Orthod Craniofac Res 18 Suppl 2, 14–24.
Al-Gunaid, T., Asahito, T., Yamaki, M., Hanada, K., Takagi, R., Ono, K., and Saito, I.
(2008). Relapse Tendency in Maxillary Arch Width in Unilateral Cleft Lip and Palate
Patients With Different Maxillary Arch Forms. Cleft Palate Craniofac. J. 45, 278–283.
Andrews, L.F. (1972). The six keys to normal occlusion. Am J Orthod 62, 296–309.
Arndt, W.V. (1993). Nickel titanium palatal expander. J Clin Orthod 27, 129–137.
Ayub, P.V., Janson, G., Gribel, B.F., Lara, T.S., and Garib, D.G. (2016). Analysis of the
maxillary dental arch after rapid maxillary expansion in patients with unilateral complete
cleft lip and palate. Am J Orthod Dentofacial Orthop 149, 705–715.
Baek, S.-H., Kim, K.-W., and Choi, J.-Y. (2010). New treatment modality for maxillary
hypoplasia in cleft patients. Protraction facemask with miniplate anchorage. The Angle
Orthodontist 80, 783–791.
Ballanti, F., Lione, R., Baccetti, T., Franchi, L., and Cozza, P. (2010). Treatment and
posttreatment skeletal effects of rapid maxillary expansion investigated with low-dose
computed tomography in growing subjects. Am J Orthod Dentofacial Orthop 138, 311–317.
88
Ballanti, F., Lione, R., Fanucci, E., Franchi, L., Baccetti, T., and Cozza, P. (2009). Immediate
and post-retention effects of rapid maxillary expansion investigated by computed
tomography in growing patients. The Angle Orthodontist 79, 24–29.
Bardach, J. (1990). The influence of cleft lip repair on facial growth. Cleft Palate J 27, 76–
78.
Barillas, I., Dec, W., Warren, S.M., Cutting, C.B., and Grayson, B.H. (2009). Nasoalveolar
molding improves long-term nasal symmetry in complete unilateral cleft lip-cleft palate
patients. Plast. Reconstr. Surg. 123, 1002–1006.
Bell, A., Ayoub, A.F., and Siebert, P. (2014). Assessment of the accuracy of a three-
dimensional imaging system for archiving dental study models. Journal of Orthodontics 30,
219–223.
Bergland, O., Semb, G., and Abyholm, F.E. (1986). Elimination of the residual alveolar cleft
by secondary bone grafting and subsequent orthodontic treatment. Cleft Palate J 23, 175–
205.
Brunetto, M., Andriani, J.D.S.P., Ribeiro, G.L.U., Locks, A., Correa, M., and Correa, L.R.
(2013). Three-dimensional assessment of buccal alveolar bone after rapid and slow maxillary
expansion: a clinical trial study. Am J Orthod Dentofacial Orthop 143, 633–644.
CG, K., Katti, G., Kallur, R., and Ghali, S.R. (2013). Magical NiTi expander. BMJ Case Rep
1–7.
Chaconas, S.J., and Caputo, A.A. (1982). Observation of orthopedic force distribution
produced by maxillary orthodontic appliances. Am J Orthod 82, 492–501.
Ciambotti, C., Ngan, P., Durkee, M., Kohli, K., and Kim, H. (2001). A comparison of dental
and dentoalveolar changes between rapid palatal expansion and nickel-titanium palatal
expansion appliances. American Journal of Orthodontics and Dentofacial Orthopedics 119,
11–20.
Corbett, M.C. (1997). Slow and continuous maxillary expansion, molar rotation, and molar
distalization. J Clin Orthod 31, 253–263.
Cotton, L.A. (1978). Slow maxillary expansion: skeletal versus dental response to low
magnitude force in Macaca mulatta. Am J Orthod 73, 1–23.
da Silva Filho, O.G., Ramos, A.L., and Abdo, R.C. (1992). The influence of unilateral cleft
lip and palate on maxillary dental arch morphology. The Angle Orthodontist 62, 283–290.
Davis, W.M., and Kronman, J.H. (1969). Anatomical changes induced by splitting of the
midpalatal suture. The Angle Orthodontist 39, 126–132.
De Clerck, H.J., Cornelis, M.A., Cevidanes, L.H., Heymann, G.C., and Tulloch, C.J.F.
(2009). Orthopedic traction of the maxilla with miniplates: a new perspective for treatment
of midface deficiency. J. Oral Maxillofac. Surg. 67, 2123–2129.
89
de Medeiros Alves, A.C., Garib, D.G., Janson, G., de Almeida, A.M., and Calil, L.R. (2016).
Analysis of the dentoalveolar effects of slow and rapid maxillary expansion in complete
bilateral cleft lip and palate patients: a randomized clinical trial. Clin Oral Investig 20, 1837–
1847.
Dixon, M.J., Marazita, M.L., Beaty, T.H., and Murray, J.C. (2011). Cleft lip and palate:
understanding genetic and environmental influences. Nat. Rev. Genet. 12, 167–178.
Donohue, V.E., Marshman, L.A.G., and Winchester, L.J. (2004). A clinical comparison of
the quadhelix appliance and the nickel titanium (tandem loop) palatal expander: a
preliminary, prospective investigation. The European Journal of Orthodontics 26, 411–420.
Enemark, H., Sindet-Pedersen, S., and Bundgaard, M. (1987). Long-term results after
secondary bone grafting of alveolar clefts. J. Oral Maxillofac. Surg. 45, 913–919.
Fearon, J.A. (2008). Rare craniofacial clefts: a surgical classification. J Craniofac Surg 19,
110–112.
Ferrario, V.F., Garattini, G., Colombo, A., Filippi, V., Pozzoli, S., and Sforza, C. (2003).
Quantitative effects of a nickel-titanium palatal expander on skeletal and dental structures in
the primary and mixed dentition: a preliminary study. The European Journal of Orthodontics
25, 401–410.
Figueiredo, D.S.F., Bartolomeo, F.U.C., Romualdo, C.R., Palomo, J.M., Horta, M.C.R.,
Andrade, I., and Oliveira, D.D. (2014). Dentoskeletal effects of 3 maxillary expanders in
patients with clefts: A cone-beam computed tomography study. Am J Orthod Dentofacial
Orthop 146, 73–81.
Fitzsimons, K.J., Mukarram, S., Copley, L.P., Deacon, S.A., and van der Meulen, J.H.
(2012). Centralisation of services for children with cleft lip or palate in England: a study of
hospital episode statistics. BMC Health Serv Res 12, 148.
Freihofer, H.P., Borstlap, W.A., Kuijpers-Jagtman, A.M., Voorsmit, R.A., van Damme, P.A.,
Heidbüchel, K.L., and Borstlap-Engels, V.M. (1993). Timing and transplant materials for
closure of alveolar clefts. A clinical comparison of 296 cases. J Craniomaxillofac Surg 21,
143–148.
Freitas, J.A. de S., Garib, D.G., Oliveira, M., Lauris, R. de C.M.C., Almeida, A.L.P.F. de,
Neves, L.T., Trindade-Suedam, I.K., Yaedú, R.Y.F., Soares, S., and Pinto, J.H.N. (2012).
Rehabilitative treatment of cleft lip and palate: experience of the Hospital for Rehabilitation
of Craniofacial Anomalies-USP (HRAC-USP)--part 2: pediatric dentistry and orthodontics.
J Appl Oral Sci 20, 268–281.
Garib, D.G., Garcia, L.C., Pereira, V., Lauris, R.C.M.C., and Yen, S. (2014). A rapid
maxillary expander with differential opening. J Clin Orthod 48, 430–435.
Gautam, P., Zhao, L., and Patel, P. (2011). Biomechanical response of the maxillofacial
skeleton to transpalatal orthopedic force in a unilateral palatal cleft. The Angle Orthodontist
81, 503–509.
90
Gibson, T.L., and Shetye, P.R. (2017). Collaborative care and the modern craniofacial
treatment team. Semin Orthod 23, 255–260.
Grayson, B.H., Santiago, P.E., Brecht, L.E., and Cutting, C.B. (1999). Presurgical
nasoalveolar molding in infants with cleft lip and palate. Cleft Palate Craniofac. J. 36, 486–
498.
Grosen, D., Chevrier, C., Skytthe, A., Bille, C., Mølsted, K., Sivertsen, A., Murray, J.C., and
Christensen, K. (2010). A cohort study of recurrence patterns among more than 54,000
relatives of oral cleft cases in Denmark: support for the multifactorial threshold model of
inheritance. J. Med. Genet. 47, 162–168.
Haas, A.J. (1965). The Treatment of Maxillary Deficiency By Opening The Midpalatal
Suture. The Angle Orthodontist 35, 200–217.
Haas, A.J. (1961). Rapid expansion of the maxillary dental arch and nasal cavity by opening
the midpalatal suture. The Angle Orthodontist 31, 73–90.
Habeeb, M., Boucher, N., and Chung, C.-H. (2013). Effects of rapid palatal expansion on the
sagittal and vertical dimensions of the maxilla: a study on cephalograms derived from cone-
beam computed tomography. Am J Orthod Dentofacial Orthop 144, 398–403.
Henry, R.J. (1993). Slow maxillary expansion: a review of quad-helix therapy during the
transitional dentition. ASDC J Dent Child 60, 408–413.
Hicks, E.P. (1978). Slow maxillary expansion. A clinical study of the skeletal versus dental
response to low-magnitude force. Am J Orthod 73, 121–141.
Holberg, C., Holberg, N., Schwenzer, K., Wichelhaus, A., and Rudzki-Janson, I. (2007).
Biomechanical analysis of maxillary expansion in CLP patients. The Angle Orthodontist 77,
280–287.
Isaacson, R.J., and Murphy, T.D. (1964). Some effects of rapid maxillary expansion in cleft
lip and palate patients. The Angle Orthodontist 34, 143–154.
Ishikawa, H., Nakamura, S., Misaki, K., Kudoh, M., Fukuda, H., and Yoshida, S. (1998).
Scar Tissue Distribution on Palates and its Relation to Maxillary Dental Arch Form. Cleft
Palate Craniofac. J. 35, 313–319.
Johnson, N., and R Sandy, J. (2003). Prenatal diagnosis of cleft lip and palate. Cleft Palate
Craniofac. J. 40, 186–189.
Jones, K.L., Jones, M.C., and del Campo, M. (2013). Smith's Recognizable Patterns of
Human Malformation (Philadelphia: Elsevier Health Sciences).
Jugessur, A., Shi, M., Gjessing, H.K., Lie, R.T., Wilcox, A.J., Weinberg, C.R., Christensen,
K., Boyles, A.L., Daack-Hirsch, S., Trung, T.N., et al. (2009). Genetic determinants of facial
clefting: analysis of 357 candidate genes using two national cleft studies from Scandinavia.
PLoS ONE 4, e5385.
91
Karaman, A.I. (2002). The effects of nitanium maxillary expander appliances on dentofacial
structures. The Angle Orthodontist 72, 344–354.
Kjaer, I. (2010). Orthodontics and foetal pathology: a personal view on craniofacial
patterning. Eur J Orthod 32, 140–147.
Krebs, A. (2009). Expansion of the Midpalatal Suture, Studied by Means of Metallic
Implants. Acta Odontologica Scandinavica 17, 491–501.
Lagravère, M.O., Major, P.W., and Flores-Mir, C. (2005). Skeletal and dental changes with
fixed slow maxillary expansion treatment: a systematic review. J Am Dent Assoc 136, 194–
199.
Lee, C.T.H., Garfinkle, J.S., Warren, S.M., Brecht, L.E., Cutting, C.B., and Grayson, B.H.
(2008). Nasoalveolar molding improves appearance of children with bilateral cleft lip-cleft
palate. Plast. Reconstr. Surg. 122, 1131–1137.
Levitt, T., Long, R.E., and Trotman, C.A. (1999). Maxillary growth in patients with clefts
following secondary alveolar bone grafting. Cleft Palate Craniofac. J. 36, 398–406.
Li, W., and Lin, J. (2007). Dental arch width stability after quadhelix and edgewise treatment
in complete unilateral cleft lip and palate. The Angle Orthodontist 77, 1067–1072.
Marazita, M.L., Lidral, A.C., Murray, J.C., Field, L.L., Maher, B.S., Goldstein McHenry, T.,
Cooper, M.E., Govil, M., Daack-Hirsch, S., Riley, B., et al. (2009). Genome scan, fine-
mapping, and candidate gene analysis of non-syndromic cleft lip with or without cleft palate
reveals phenotype-specific differences in linkage and association results. Human Heredity
68, 151–170.
Marzban, R., and Nanda, R. (1999). Slow maxillary expansion with nickel titanium. J Clin
Orthod 33, 431–441.
Maull, D.J., Grayson, B.H., Cutting, C.B., Brecht, L.L., Bookstein, F.L., Khorrambadi, D.,
Webb, J.A., and Hurwitz, D.J. (1999). Long-term effects of nasoalveolar molding on three-
dimensional nasal shape in unilateral clefts. Cleft Palate Craniofac. J. 36, 391–397.
Meyer, S., and Mølsted, K. (2013). Long-term outcome of secondary alveolar bone grafting
in cleft lip and palate patients: a 10-year follow-up cohort study. J Plast Surg Hand Surg 47,
503–508.
Miura, F., Mogi, M., Ohura, Y., and Hamanaka, H. (1986). The super-elastic property of the
Japanese NiTi alloy wire for use in orthodontics. American Journal of Orthodontics and
Dentofacial Orthopedics 90, 1–10.
Mossey, P.A., Little, J., Munger, R.G., Dixon, M.J., and Shaw, W.C. (2009). Cleft lip and
palate. Lancet 374, 1773–1785.
Murray, J.C. (2002). Gene/environment causes of cleft lip and/or palate. Clinical Genetics
61, 248–256.
92
Newlands, L.C. (2000). Secondary alveolar bone grafting in cleft lip and palate patients. Br
J Oral Maxillofac Surg 38, 488–491.
Nicholson, P.T., and Plint, D.A. (1989). A long-term study of rapid maxillary expansion and
bone grafting in cleft lip and palate patients. The European Journal of Orthodontics 11, 186–
192.
Pan, X., Qian, Y., Yu, J., Wang, D., Tang, Y., and Shen, G. (2007). Biomechanical effects
of rapid palatal expansion on the craniofacial skeleton with cleft palate: a three-dimensional
finite element analysis. Cleft Palate Craniofac. J. 44, 149–154.
Parker, S.E., Mai, C.T., Canfield, M.A., Rickard, R., Wang, Y., Meyer, R.E., Anderson, P.,
Mason, C.A., Collins, J.S., Kirby, R.S., et al. (2010). Updated National Birth Prevalence
estimates for selected birth defects in the United States, 2004-2006. Birth Defects Res. Part
a Clin. Mol. Teratol. 88, 1008–1016.
Patel, P.A., Rubin, M.S., Clouston, S., Lalezaradeh, F., Brecht, L.E., Cutting, C.B., Shetye,
P.R., Warren, S.M., and Grayson, B.H. (2015). Comparative Study of Early Secondary Nasal
Revisions and Costs in Patients With Clefts Treated With and Without Nasoalveolar
Molding. J Craniofac Surg 26, 1229–1233.
Peanchitlertkajorn, S., Mercado, A., Daskalogiannakis, J., Hathaway, R., Russell, K., Semb,
G., Shaw, W., Lamichane, M., Cohen, M., and Long, R.E., Jr (2018). An Intercenter
Comparison of Nasolabial Appearance Including a Center Using Nasoalveolar Molding. The
Cleft Palate-Craniofacial Journal 28, 105566561875494.
Raju, P., Agarwal, D.K., Bhattacharya, P., Garg, J., and Gupta, A. (2014). Maxillary
expansion by nickel titanium palatal expander in cleft palate patient. J NTR Univ Health Sci
3, 51–54.
Reitan, K. (1951). The initial tissue reaction incident to orthodontic tooth movement as
related to the influence of function; an experimental histologic study on animal and human
material. Acta Odontol Scand Suppl 6, 1–240.
Reuschl, R.P., Heuer, W., Stiesch, M., Wenzel, D., and Dittmer, M.P. (2016). Reliability and
validity of measurements on digital study models and plaster models. Eur J Orthod 38, 22–
26.
Robertson, N.R., and Fish, J. (1972). Some observations on rapid expansion followed by
bone grafting in cleft lip and palate. Cleft Palate J 9, 236–245.
Ross, R.B. (1970). The clinical implications of facial growth in cleft lip and palate. Cleft
Palate J 7, 37–47.
Rune, B., Sarnäs, K.V., Selvik, G., and Jacobsson, S. (1980). Movement of maxillary
segments after expansion and/or secondary bone grafting in cleft lip and palate: a roentgen
stereophotogrammetric study with the aid of metallic implants. Am J Orthod 77, 643–653.
93
Santiago, P.E., Grayson, B.H., Cutting, C.B., Gianoutsos, M.P., Brecht, L.E., and Kwon,
S.M. (1998). Reduced need for alveolar bone grafting by presurgical orthopedics and primary
gingivoperiosteoplasty. Cleft Palate Craniofac. J. 35, 77–80.
Sato, Y., Grayson, B.H., Garfinkle, J.S., Barillas, I., Maki, K., and Cutting, C.B. (2008).
Success rate of gingivoperiosteoplasty with and without secondary bone grafts compared
with secondary alveolar bone grafts alone. Plast. Reconstr. Surg. 121, 1356–67–
discussion1368–9.
Sell, D., Mildinhall, S., Albery, L., Wills, A.K., Sandy, J.R., and Ness, A.R. (2015). The Cleft
Care UK study. Part 4: perceptual speech outcomes. Orthod Craniofac Res 18 Suppl 2, 36–
46.
Shetye, P.R., and Grayson, B.H. (2017). NasoAlveolar molding treatment protocol in patients
with cleft lip and palate. Semin Orthod 23, 261–267.
Shi, M., Christensen, K., Weinberg, C.R., Romitti, P., Bathum, L., Lozada, A., Morris, R.W.,
Lovett, M., and Murray, J.C. (2007). Orofacial cleft risk is increased with maternal smoking
and specific detoxification-gene variants. Am. J. Hum. Genet. 80, 76–90.
Shi, M., Wehby, G.L., and Murray, J.C. (2008). Review on genetic variants and maternal
smoking in the etiology of oral clefts and other birth defects. Birth Defects Res. C Embryo
Today 84, 16–29.
Sousa, M.V.S., Vasconcelos, E.C., Janson, G., Garib, D., and Pinzan, A. (2012). Accuracy
and reproducibility of 3-dimensional digital model measurements. Am J Orthod Dentofacial
Orthop 142, 269–273.
Stone, C. (2013). Cleft Lip and Palate: Etiology, Epidemiology, Preventive and Intervention
Strategies. Anatomy & Physiology 04.
Storey, E. (1973). Tissue response to the movement of bones. Am J Orthod 64, 229–247.
Subtelny, J.D. (1955). The Significance Of Early Orthodontia In Cleft Palate Habilitative
Planning. Journal of Speech and Hearing Disorders 20, 135–147.
Tessier, P. (1976). Anatomical classification facial, cranio-facial and latero-facial clefts. J
Maxillofac Surg 4, 69–92.
Tindlund, R.S., and Rygh, P. (1993). Soft-tissue profile changes during widening and
protraction of the maxilla in patients with cleft lip and palate compared with normal growth
and development. Cleft Palate Craniofac. J. 30, 454–468.
Tindlund, R.S., Rygh, P., and Bøe, O.E. (1993). Intercanine widening and sagittal effect of
maxillary transverse expansion in patients with cleft lip and palate during the deciduous and
mixed dentitions. Cleft Palate Craniofac. J. 30, 195–207.
Turvey, T.A., Vig, K., Moriarty, J., and Hoke, J. (1984). Delayed bone grafting in the cleft
maxilla and palate: a retrospective multidisciplinary analysis. Am J Orthod 86, 244–256.
94
Vasant, M.R., Menon, S., and Kannan, S. (2009). Maxillary Expansion in Cleft Lip and
Palate using Quad Helix and Rapid Palatal Expansion Screw. Med J Armed Forces India 65,
150–153.
Vig, K.W.L., and Mercado, A.M. (2015). Overview of orthodontic care for children with
cleft lip and palate, 1915-2015. Am J Orthod Dentofacial Orthop 148, 543–556.
Vlachos, C.C. (1996). Orthodontic treatment for the cleft palate patient. Semin Orthod 2,
197–204.
Wang, Y.B., Zheng, Y.F., and Liu, Y. (2009). Effect of short-time direct current heating on
phase transformation and superelasticity of Ti–50.8at.%Ni alloy. Journal of Alloys and
Compounds 477, 764–767.
Waylen, A., Ness, A.R., Wills, A.K., Persson, M., Rumsey, N., and Sandy, J.R. (2015). Cleft
Care UK study. Part 5: child psychosocial outcomes and satisfaction with cleft services.
Orthod Craniofac Res 18 Suppl 2, 47–55.
Wehby, G.L., and Murray, J.C. (2010). Folic acid and orofacial clefts: a review of the
evidence. Oral Dis 16, 11–19.
Wermker, K., Jung, S., Joos, U., and Kleinheinz, J. (2014). Dental implants in cleft lip,
alveolus, and palate patients: a systematic review. Int J Oral Maxillofac Implants 29, 384–
390.
Wertz, R., and Dreskin, M. (1977). Midpalatal suture opening: a normative study. Am J
Orthod 71, 367–381.
Wilcox, A.J., Lie, R.T., Solvoll, K., Taylor, J., McConnaughey, D.R., Abyholm, F.,
Vindenes, H., Vollset, S.E., and Drevon, C.A. (2007). Folic acid supplements and risk of
facial clefts: national population based case-control study. Bmj 334, 464.
Wirthlin, J.O. (2017). The orthodontist’s role in the management of patients with cleft lip
and palate undergoing alveolar bone grafting. Semin Orthod 23, 268–278.
Wong, C.A., Sinclair, P.M., Keim, R.G., and Kennedy, D.B. (2011). Arch dimension changes
from successful slow maxillary expansion of unilateral posterior crossbite. The Angle
Orthodontist 81, 616–623.
Yang, C.-J., Pan, X.-G., Qian, Y.-F., and Wang, G.-M. (2012). Impact of rapid maxillary
expansion in unilateral cleft lip and palate patients after secondary alveolar bone grafting:
review and case report. Oral Surg Oral Med Oral Pathol Oral Radiol 114, e25–e30.
Yoon, H., Chung, I.S., Seol, E.Y., Park, B.Y., and Park, H.W. (2000). Development of the
lip and palate in staged human embryos and early fetuses. Yonsei Med. J. 41, 477–484.
Zimring, J.F., and Isaacson, R.J. (1965). Forces Produced By Rapid Maxillary Expansion. III
Forces Present During Retention. The Angle Orthodontist 35, 178–186.
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8. APPENDIX

Outline

a. List of Figures
b. List of Tables
c. Sample of Consent Form
d. Sample of Assent Form
e. Tables with Data
1. NiTi Group
2. QH Group
3. RPE Group

96
a. List of Figures

Figure 1: Developmental fields
Figure 2: Tessier classification of facial and cranial clefts
Figure 3: Fearon’s surgical classification of clefts:
Figure 4: Development of the face
Figure 5: Representation of the developmental fields in the palate and face
Figure 6: Closure of the secondary palate
Figure 7: Complete forms of CLP.
Figure 8: Different forms of incomplete CLP
Figure 9: NAM Appliance.
Figure 10: Anatomy of the ear and diagram of a myringotomy.
Figure 11: Secondary alveolar bone graft surgery being performed.
Figure 12: Skeletal and dental effects of RME and SME.
Figure 13: Effect of maxillary expansion to regain the archform in patients with CLP with
collapsed alveolar segments. Once the archform is regained, there will be room for the
alveolar bone graft.
Figure 14: Description of the NiTi expander components.
Figure 15: Quad-Helix expander used for expansion of the patients in group 1 in Center 1.
Figure 16: Hyrax-type rapid palatal expander used for expansion of the patients in group 2 at
Center 2.
Figure 17: Welding lingual sheaths to the bands.
Figure 18: Selecting and reprogramming the NiTi expander.
Figure 19: Adapting the SS arms to the lateral segments of the maxillary dentition using a
bird beak plier and a three prong plier.
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Figure 20: Measuring the intensity of the current of setting number 8 of the Bender Soarer-
X equipment with a digital multimeter.
Figure 21: Measuring the maxillary and mandibular intercanine distance in one of the patients
of the study.
Figure 22: Comparison of an expander before reprogrammation (left expander) and after
being widened with the Bender Soarer-X equipment (right expander).
Figure 23: 3Shape R700 3D laser scanner (3Shape A/S, Copenhagen, Denmark).
Figure 24: Occlusal and cervical transverse dimensions of one patient.
Figure 25: Arch length and arch perimeter of one patient.
Figure 26: Palatal depth of one patient.
Figure 27: Measurement of the angulation of the teeth to the occlusal plane.
Figure 28: Before and after expansion values within the NiTi group.
Figure 29: Changes within the NiTi group.
Figure 30: Initial records of a patient of the NiTi group (T1)
Figure 31: NiTi Expander in place
Figure 32: Final records of a patient of the NiTi group (T2: 6 post-expansion)
Figure 33: Before and after expansion values within the QH group.
Figure 34: Changes within the QH group.
Figure 35: Before and after expansion values within the RPE group.
Figure 36: Changes within the RPE group. All variables showed statistically significant
changes.
Figure 37: Comparison of the changes between groups.
Figure 38: Comparison of the width changes between groups at the occlusal. Statistically
significant differences between all variables except 3-3.
Figure 39: Comparison of the width changes between groups at the gingival margin.
Statistically significant differences between the groups for all variables except 3-3’.
98
Figure 40: Arch perimeter before and after expansion for all groups. Statistically significant
differences between all groups.
Figure 41: Comparison of the net changes in arch perimeter. Statistically significant
differences between all the groups.
Figure 42: First molar inclination (buccal tipping) before and after expansion for all groups.
Statistically significant differences between all groups.
Figure 43: Comparison of the net changes in first molar inclination to the occlusal plane
(buccal tipping). Statistically significant differences between all the groups.
Figure 44: Complication: wire embedment in the palatal tissue of an oversized expander.

99
b. List of Tables

Table 1. Equivalence of Tessier to Fearon’s classification of clefts.

Table 2. Genes with a role in non-syndromic CLP. (This table is a replication from Table 2
in (Dixon et al., 2011))

Table 3. Comparison of starting values between the groups (ANOVA and Kruskal Wallis)

Table 4. Comparison between pre- and post-expansion within the NiTi group (paired t-test
and Wilcoxon test). T1 = pre-expansion, T2 = 6 months post-expansion.

Table 5. Comparison between pre- and post-expansion within the QH group (paired t-test
and Wilcoxon test). T1 = pre-expansion, T2 = 6 months post-expansion.

Table 6. Comparison between pre- and post-expansion within the RME group (paired t-test
and Wilcoxon test). T1 = pre-expansion, T2 = 6 months post-expansion.

Table 7. Comparison of the treatment changes between the three groups (ANOVA and
Kruskal Wallis).

100
c. Sample of Consent Form

Children’s Hospital Los Angeles
PERMISSION TO PARTICIPATE IN A RESEARCH STUDY

Study of Orthodontic Devices to Repair the Upper Jaw in Patients with Cleft Lip and Palate

Subject’s Name:
CHLA#:
Birth
Date:

Your child is invited to participate in a research study conducted by Stephen Yen, DMD,
PhD from the Division of Dentistry at Children’s Hospital Los Angeles (CHLA). The
research is sponsored by the Division of Dentistry at CHLA. Participation in this study is
completely voluntary.

The purpose of the study is to analyze three types of expanders used to expand the upper
jaw in patients with cleft lip and palate to prepare it for bone graft surgery. This study will
examine one of the three methods, the slow expansion with flexible archwires, with 30
patients from CHLA.

If you allow your child to participate in this study, the plaster models of their teeth that are
normally taken before and 6 months after expansion treatment will be analyzed with a laser
scanner. His/her participation will last approximately 6 months. Only the models will be
used in this study so your son or daughter cannot be identified from the data we are
gathering.

The pre- and post- expansion plaster models will be scanned with a laser scanner into a
digital model which can be measured. At the time of scanning, all identifying information
will be removed and replaced with only a study ID number and treatment type. We do not
need to know any personal information.

This research involves the potential risk of accidental release of confidential information.
You should not expect any direct benefit to your child as a result of participating in this
research.

The alternative to participation is to not participate.

There will be no financial obligations for the participant.

Only the research team will know that your child is a research subject and have access to
the information he/she provides. None of the information will be disclosed to others;
except if necessary to protect your child’s rights or welfare or if required by law (i.e., harm
to self or others, reports of certain infectious diseases). Your child will not be identified in
101
publications of the research results. Authorized representatives of the CHLA Institutional
Review Board may review subject records but are bound by rules of confidentiality not to
reveal your child’s identity.

If you agree to allow your child to participate, but later decide to withdraw your child from
the study, you may do so without affecting you or your child’s rights to health care,
services or other benefits at CHLA.

If there is significant new information found during the course of the study that might affect
your decision to allow your child to participate in the study, or the study plan is changed,
you may be informed and your permission to allow your child to continue participating in
the study may be requested again.

If you have questions about the research or wish to report a concern or complaint about the
research, the Principal Investigator, Stephen Yen, DMD, PhD may be reached at (323) 361-
2130. Your child may withdraw from this study at any time and discontinue participation
without penalty. Your child is not waiving any legal claims, rights or remedies because of
his/her participation in this research study. If you have questions regarding the rights of
research subjects or if you have complaints or concerns about the research and cannot reach
the Principal Investigator; or just want to talk to someone other than the Investigator, you
may call the CHLA Human Subjects Protection Program at (323) 361-2265.

SIGNATURE OF PARENT(S)/LEGAL GUARDIAN(S)

Your signature(s) below indicates
• You have read this document and understand its meaning;
• You have had a chance to ask questions and have had these questions answered to
your satisfaction;
• You agree to your child’s participation in this research study;
• You will be given a signed copy of this form and a signed copy of the HIPAA
authorization form.

____________________________________
____________________________________
Print Name(s) of Parent(s)/Legal Guardian(s)

____________________________________ ______________
Signature of Parent/Legal Guardian Date

____________________________________ ______________
Signature of Parent/Legal Guardian Date

102

SIGNATURE OF INVESTIGATOR/PERSON OBTAINING CONSENT

I have explained the research to the subject’s parent(s)/legal guardian(s) and have answered
all of their questions. I believe that they understand all of the information described in this
document and freely give permission for their child to participate.

____________________________________
Print Name of Individual Obtaining Consent

____________________________________ ______________
Signature of Individual Obtaining Consent Date

SIGNATURE OF WITNESS (if applicable)

My signature as Witness indicates that the subject’s parent(s)/legal guardian(s) voluntarily
signed this permission form in my presence.

____________________________________
Print Name of Witness

____________________________________ ______________
Signature of Witness Date

SIGNATURE OF INTERPRETER (if applicable)

____________________________________
Print Name of Interpreter

____________________________________ ______________
Signature of Interpreter Date

103
Complete if applicable:
Please check appropriate box and sign below.

Investigator/person obtaining consent’s statement of certification for subjects less than seven
years of age (assent):

The undersigned, _____________________, hereby certifies that assent was obtained for a
subject.

Assent was not obtained for a subject under 18 years of age. (Please state the reason.
Examples include: child is an infant; child is comatose; child lacks cognitive abilities to
understand the information.)

_____________________________________________________________________________

_____________________________________________________________________________

Date:_____________

Time:______________ Signature_________________________________________

Routing of signed copies of the form:
1) Give to the parent/legal guardian (copy)
2) Place in the Principal Investigator’s research file (original)

104
d. Sample of Assent Form

Children’s Hospital Los Angeles
ASSENT TO PARTICIPATE IN A RESEARCH STUDY

A Study of Special Braces Used to Repair the Upper Jaw in Children with
Cleft Lip and Palate
Subject’s Name:
CHLA#:

Birth Date:

1. Dr. Stephen Yen is doing a research study about Cleft Lip and Palate. The
word cleft means a split between two things. A cleft lip is a split in the upper lip.
A cleft palate is a split in the roof of the mouth.

2. We are asking you to take part in this research because you have a cleft lip and
palate and your dentist is going to put special braces in your mouth to help you have
a better smile by fixing the spaces between the teeth at the top of your mouth. We
want to see how good these braces work.

3. If you agree to be in this study, you will be asked to:
Let us use the models we take of your teeth before the dentist puts in your special
braces and 6 months after you get your braces. We will scan the models into a
computer and take measurements.

When you are in a research study, sometimes good things and bad things can happen:

4. Things that happen to children in research studies that make them feel bad are called
“risks.” Some of the bad things for this research study could be:
• Someone who isn’t a part of doing the study might find out information
about you. This may happen to you. Or things may happen that the doctors
don’t know about yet.

5. Things that happen to children in research studies that are good are called
“benefits.” Some of the good things for this research study could be:
• By being in this study you may help future children with cleft lip and palate.
It may make you feel good to help someone else.
6. We will do everything possible to keep your information private.

7. You do not have to be in this study if you don’t want to. You may stop being in this
study at any time. Remember, being in this study is up to you.
105

8. Please talk with your parents before you decide whether or not to be in this study.
We will also ask your parents to give their permission for you to take part in this
study. But even if your parents say “yes,” you can still decide not to do this.

9. You can ask any questions that you have about the study. If you have a question
later that you didn’t think of now, please write it down to help you remember. You
can call me or ask me next time you see me.

323-361-2130

10. Signing your name at the bottom means that you agree to be in this study. Your
doctors will still take good care of you whether or not you agree to be in this study.

Yes, I agree to be in this research study.

_____________________________________ ________________
Signature of Subject Date

_____________________________________
Print Name of Individual Obtaining Assent

_____________________________________ ________________
Signature of Individual Obtaining Assent Date

Routing of signed copies of the assent form:
1) Give to the child (copy)
2) Give to the parent/legal guardian (copy)
3) Place in the Investigator's research files (original)

106
e. Tables with Data

1. NiTi Group

T1

107
T2

108
2. QH Group

T1

109
T2

110
3. RPE Group

T1

111
T2

Abstract (if available)

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Asset Metadata

Creator Torres Moneu, Ana (author)

Core Title Reprogramming the NiTi expander: an alternative to conventional rapid and slow maxillary expansion modalities for the treatment of patients with cleft lip and palate

School School of Dentistry

Degree Master of Science

Degree Program Craniofacial Biology

Publication Date 04/12/2018

Defense Date 03/02/2018

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag bone graft,cleft lip,cleft lip and palate,cleft palate,dental arch,expansion,maxilla,midfacial growth,NiTi,nonsyndromic clefting,OAI-PMH Harvest,orthodontics,orthopedic treatment,palatal development,palatal expander,Quality of life

Language English

Contributor Electronically uploaded by the author (provenance)

Advisor Yen, Stephen (committee chair), Paine, Michael (committee member), Sameshima, Glenn (committee member)

Creator Email anatorresmoneu@gmail.com,torr541@usc.edu

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c89-7428

Unique identifier UC11671306

Identifier etd-TorresMone-6244.pdf (filename),usctheses-c89-7428 (legacy record id)

Legacy Identifier etd-TorresMone-6244.pdf

Dmrecord 7428

Document Type Thesis

Rights Torres Moneu, Ana

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the a...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus MC 2810, 3434 South Grand Avenue, 2nd Floor, Los Angeles, California 90089-2810, USA