Close
About
FAQ
Home
Collections
Login
USC Login
Register
0
Selected
Invert selection
Deselect all
Deselect all
Click here to refresh results
Click here to refresh results
USC
/
Digital Library
/
University of Southern California Dissertations and Theses
/
Who is reading the digital radiography and the cone beam computed tomography?
(USC Thesis Other)
Who is reading the digital radiography and the cone beam computed tomography?
PDF
Download
Share
Open document
Flip pages
Contact Us
Contact Us
Copy asset link
Request this asset
Transcript (if available)
Content
Who Is Reading the Digital Radiography
and the Cone Beam Computed
Tomography?
Yassmin Badran
This thesis is submitted in partial fulfillment of the requirements
for the degree of Master of Science
Craniofacial biology
Herman Ostrow School of Dentistry
University of Southern California
August 2017
Table of Content
Acknowledgment ………………………………………………………... 1
Author’s Declaration …………………………………………………..… 2
Abstract ……………………………………………………………..…… 3
List of Figures ………………………………………………………..….. 4
List of Tables ……………………………………………………..…..….. 5
1. Introduction ……………………………………………………..……. 6
2. Review of Literature …………………………………………….....….. 10
3. Aims …………………………………………………………………… 15
4. Materials and Methods ……………………………………………..….. 16
4.1 Sample Selection and Data Collection ………………...….….. 16
4.2 Data storage and Processing …………………………………. 17
4.3. Image Viewing ………………………………………………. 18
4.4 Statistical Analysis………………………………………………… 19
5. Results ………………………………………………………….…..…. 21
5.1. Inter-observer Reliability ……………………………………. 21
5.2. Intra-observer Reliability ………..………………..……....…. 22
5.3. Observation Time …………………………………...…….…. 23
5.4. Inter-observer Agreement by Level of Experience ……...…... 26
6. Discussion ………………………………………………………..….…. 30
7. Conclusion ……………………………………………………….…….. 34
8. Reference ………………………………………………………….....…. 35
1
Acknowledgment
First, I would like to acknowledge all of my supervisors of this research who made it
happen: Dr. Rafael Roges, Dr. Ilan Rotstein, and Micheal Paine.
I would like to express my appreciating to Dr. Rafael Roges who made this project
possible. Thank you for your valuable input, guidance, and support you have provided me
in this research.
I would also like to give my sincere thanks to Dr. Ilan Rotstein. I appreciate your help,
guidance, and expertise.
Many thanks to the Endodontic Department, including Norma Vasqus and Diana
Mondorf, for bearing with my daily requests and using the space while conducting my
research, and for their understanding.
I would also like to express my gratitude to Dr. Daniel Sheckter, Dr. Stefan Zweig, Dr.
Elham Radan, for participating in the study.
I also wish to extend my thankfulness to Dr. Steven Park, Dr. Sara Abbadat, Dr. Grace
Lin, for their participation.
Special thanks for Melissa Wilson for her statistical support in this project.
2
Author’s Declaration
I, Yassmin Badran, declare that this dissertation is the result of my own work.
The study was designed by Dr. Rafael Roges and myself. All statistical analyses included
in this dissertation were carried out by Melissa Wilson, department of preventive
medicine, University of Southern California.
3
Abstract
Aims. To evaluate the inter-rater reliability and intra-rater reliability when evaluating
digital periapical radiographic (PR) images compared to that of cone-beam computed
tomography scans (CBCT).
Materials and Methods. 6 observers including 3 endodontists, 3 second year endodontic
residents, and 1 radiologist independently evaluated 100 molar digital radiographs and
100 CBCT scans to determine the presence of a periapical radiolucency of endodontic
origin and scored either: “yes”, “No”, or “Uncertain”. Each examiner was able to use all
of the software enhancement tools and had full access to the software’s features. All six
observers re-examined the same digital images and scans 3 months later. No time limit
was set for both evaluation sessions, and the time until each evaluator made a decision for
each image was recorded in each session. The data were analyzed to determine the inter-
examiner and intra-examiner agreement. Linear mixed models were used to determine the
time taken to evaluate each modality.
Results. Kappa for inter-rater reliability in the first observation session for periapical
radiography ranged from 0.03 to 0.44, combined K= 0.30 (p<.001) and at three months
showed a similar pattern and range (0.04-0.44), with a combined Kappa of 0.35 (p<.001),
suggesting fair agreement. Kappa in the first session for CBCT ranged 0.03-0.39 and
0.06-0.46 at three months. The combined Kappa at baseline CBCT reading was 0.31
(p<.001) and 0.40 (p<.001) at the second reading three months later; also suggesting fair
agreement. Kappa for intra-rater reliability for periapical radiography ranged from 0.38 to
0.63 (p<.001 for all) and between 0.40 to 0.64 for CBCT (p<.001 for all); showing
moderate agreement among the 6 observers. Also, it takes 67 seconds more to read a
CBCT scan compared to a digital periapical radiograph.
Conclusion. Variation in interpreting digital radiographs and CBCT scans was found.
The study concludes that reading an image in the diagnostic process of endodontic
therapy is still a subjective matter.
4
List of Figures
Figure 1. Study flow diagram showing the process of selection of records.
Figure 2: Periapical Radiograph (PR) Time by Rater at First Reading
Figure 3: Cone Beam Computed Tomography (CBCT) Time by Rater at First Reading
Figure 4: Periapical Radiograph (PR) Time by Rater at Second Reading
Figure 5: Cone Beam Computed Tomography (CBCT) Time by Rater at Second
Reading
5
List of Tables
Table1. Interpretation of Kappa Statistics
Table 2. Inter-rater reliability (Agreement) between six raters for digital periapical
radiographs (PR) and cone beam computed tomography (CBCT)
Table 3. Intra-rater reliability (Agreement) for each observer for digital periapical
radiographs (PR) and cone beam computed tomography (CBCT)
Table 4. Difference in the reading time between the digital periapical radiographs
(PR) and cone-beam computed tomography scans (CBCT)
Table.5 Combined inter-rater agreement for digital periapical radiographs (PR)
and cone beam tomography (CBCT) by level of experience
Table 6. Pairwise inter-rater agreement amongst faculty and resident subgroups
for
digital periapical radiographs (PR) and cone beam computed tomography (CBCT)
Table 7. Combined inter-rater agreement for digital periapical radiographs (PR)
and cone beam tomography (CBCT) by tooth location (Upper or Lower)
6
1. Introduction
Endodontic imaging has evolved considerably since its introduction. The commonly
used intra-oral imaging techniques in the endodontic field, the conventional films and digital
imaging system, are two-dimensional image-producing systems. Digital radiographic (DR)
systems are superior to conventional films due to their lower radiation doses, instantaneous
images, and ease of manipulation (1). Conventional and digital radiographs yield limited
information, and can be considered to produce default images, because the images produced
restricts visual analysis of certain anatomical regions, as well as the size, extension and
location of periapical lesions (2). Limitations of reading and interpreting intraoral
radiographs still exist. More specifically, clinicians may not agree with each other regarding
existence or healing of periapical pathoses when evaluating intra-oral conventional
radiographs (3). Recently, with the advancements in medical technologies, cone-beam
computed tomography has entered the dental field.
In endodontics, information obtained from radiographs is important for diagnosis, correct case
selection, and appropriate treatment decision-making and outcome assessment (4). Regardless of
the radiographic system used, radiographic examination is an essential part of the endodontic
therapy. Intraoral and panoramic radiography are mostly used in most dental offices. However,
since the introduction of cone beam computed tomography (CBCT), the awareness and use of such
technology has markedly increased (5). A survey conducted to assess the application of CBCT
among dental school in the US, UK, and Australia have reported that a large number of the dental
schools in these countries teach the use CBCT in their programs (5). Radiographic examination
completes the clinical examination, hence, an image presenting a three dimensional view will be of
7
benefit for clinicians (6). The advent of CBCT in the endodontic field provides a great deal of
information helping the clinician to accurately determine the presence of peri-radicular rarefactions,
and plan the proper endodontic therapy for each case. Therefore, to improve the quality of the
information when dealing with periapical lesions the possibility of using CBCT may be considered
when the need for an acceptable image that cannot be seen using the 2D- imaging systems (7).
CBCT was first introduced into the dental field by Mozzo et al 1998 and Arai et al I 1999, to
produce a three-dimensional scan of the cranio-maxillo-facial region (8,9). To produce a three
dimensional image, the CBCT machine uses a cone shaped X-ray beam that rotates in a 180-360
direction around the patient’s head, aiming at a 2D sensor (10). The exposure time of the scan
ranges between 10-40s, the data can be collected into personal computers, and the image is
reconstructed with in minutes (10). Moreover, the 3D scans allows the clinician to view the area of
interest in three different planes, axial, coronal, and sagittal views. Cone beam computed
tomography provides three different fields of view or scan volume, and these include large field of
view, small field of view, and focused or limited field of view (FOV) (11,12). They all differ in the
scan volume height, where the limited field of view is a 5cm or less view of the region of interest
compared to the large FOV that allows the entire maxilla or mandible to be scanned (11). The
advantages of these machines have resulted in the increase in its acquisition by many clinicians and
dental schools (5).
Based on the AAE and AAOMR ioint position paper regarding the use of cone beam
computed tomography, in endodontics, limited field of view CBCT systems are preferred, because
of the lower radiation dose and the high resolution it offers compared to the large field of view
(2015)(7). According to the AAE and AAOMR joint position paper, the following are certain
recommendations about when a CBCT scan should be offered to patients. Limited field of view
8
(FOV) CBCT should be the imaging modality of choice when: suspecting complex endodontic
anatomy, to assess endodontic treatment complications, non-healing of previous endodontic
treatment, resorptive defects, in the management of dental trauma, surgical endodontic and implant
treatment planning.
Although the CBCT imaging is beneficial in dental and specialty offices, it has some
disadvantages. The image quality of the scan can be affected by the presence of artifacts, lowering it
diagnostic property. The presence of radio-opaque structures or materials adjacent to the area of
interest can cause scatter and beam hardening (13). These artifacts create dark streaks and are seen
when a high-density object such as titanium, metal restorations, and enamel is adjacent to the area
of interest (10). The cost of the CBCT machine is a significant problem compared to the other
imaging modalities. Ludlow et al 2008, reported that CBCT imaging of the limited Field of view
exposes the patients with a radiation effective dose that ranges between 5.3-21.7 microseivert; while
the range of the radiation effective dose from a periapical radiography is 0.4- 2.7 microseivert.
These values indicate that although the radiation effective dose of the focused FOV is lower
compared to other field of views, the CBCT offers high radiation exposure compared to other dental
imaging modalities, panoramic and periapical radiography (10, 14).
Diagnosis in endodontics is a complex process that entails both clinical and radiographic
examination. With the availability of the different types of imaging offered to aid in diagnosis and
treatment planning, interpreting a radiograph to make a decision remains difficult. It is essential that
the available diagnostic tools are reliable and reproducible, or else they are of minimal benefits in
the process of managing endodontic problems. Previous literature has reported great variability
amongst examiners when evaluating radiograph images. It has been reported that assessing the
periapical status in a periapical radiograph between endodontists and oral radiologists varies (15).
9
Also, observer variability when viewing a radiographic image was assessed by Goldman et al, 1974
(16). In addition, Tewary et al. 2011, have further investigated observer variability using direct
digital radiography, and re-emphasized that there is a high observer variability when viewing a
radiographic image (17). Goldman stated in his article, that “we do not read radiographs, we
interpret them”. This sheds light to the previous notion, today with the advent of CBCT, the real
unanswered question is, have we become more consistent in our radiographic interpretations? This
is the question that will be answer today in this study.
10
2. Review of Literature
Radiography remains an important tool that aids in the diagnosis and the treatment planning
for oral health diseases. Radiographic technology has advanced, the availability of the cone beam
computed tomography provides more information for clinicians. It has been shown to be useful in
the management of endodontic problems because it over comes some of the limitations of intraoral
radiography.
Digital intraoral radiography is an essential constituent of endodontic diagnosis and
treatment planning since the time it was introduced (18, 19). However, it is part of the two
dimensional radiography. The 2D images produced are missing relevant information
regarding the size, extension and location of a periapical lesion, where the more mineralized
cortical bone overlying the cancellous bone (where periapical lesions are first evident), and
geometric distortion can under-represent the size of a periapical lesion or inhibit the ability
to visualize the lesion (2,20). The imitations of periapical radiography have directed
clinicians to consider other imaging modalities. The inability to take parallel radiographs
because of certain anatomical variations and the sizes of the sensors of digital radiography
causes the geometric distortion, hence, limits the ability to assess the periapical tissues
(16,21). Regarding the use of conventional dental radiographic film and digital radiography,
Barbat et al 1998, compared using post-mortem mandibles , he concluded that these imaging
modalities showed comparable diagnostic accuracy (22). In addition, the imaging
enhancement feature of the digital did not increase the diagnostic accuracy (22).
The Cone-beam computed tomography was first introduced into the dental field by
11
Mozzo et al 1999, and that technology created a path for the three-dimensional imaging to
be considered in the endodontic field (8). Considering its introduction, many studies were
done to evaluate this new imaging modality in its application in endodontics. Several studies
(23-25) have evaluated the reliability of CBCT for root length determination and tooth
movement for orthodontic treatment. For pre-operative assessment, a study evaluated the
detection of root canals using intraoral radiography and CBCT. In that study, the average
root canals detected by the observers on CBCT was more than that on intraoral radiography
(26). In another study concerning the root canal system, the prevalence of detection of the
MB2 canal of the maxillary first molars is higher when observed by the CBCT (11). CBCT
is also useful in management of complex anatomy cases such as dilacerated roots and dens
invaginatus cases (10,12).
Differentiating between the different types of root resorptions clinically is difficult.
Several case reports have been published describing the benefits of CBCT usage in the
diagnosis, treatment planning and managing of resorptive defect lesions. In an attempt to
evaluate the success of the CBCT utility when diagnosing a resorption case, Cohenaca et al.
2007 noted that CBCT can be used to successfully differentiate internal root resorption from
external root resorption (27). Simon et al. 2006, assessed the ability of CBCT using
Humsfield scale, to differentiate between a ‘solid ’ type lesion from a ‘cavity type lesion’,
and stated that the grey scale value measurement offered by such technology aids in the
differentiating between these different periapical lesion characteristics (27). For the
management of dental trauma, including the alveolar and luxation, CBCT was reported to be
successful when used in the diagnosis and management process (10,27).
Vertical root fracture presents a difficult diagnostic problem in endodontics. For
12
accurate diagnosis of vertical root fractures, both clinical and radiographic examinations are
essential, may sometimes requires surgical intervention for evaluation. Hence, many authors
have reported the benefits of the 3D imaging in visualizing the fracture line in vertical root
fracture cases (29). Additionally, the AAE and AAOMR joint position paper has proposed
their recommendations regarding CBCT usage in endodontics, and stated that it’s the
primary imaging modality when planning for surgical procedures (2015)(7). The reason
behind that is based on the fact that the CBCT image shows the location and proximity of
the teeth with the adjacent anatomical structures (7). Moreover, the CBCT helps clinician
investigate the proximity of the maxillary posterior teeth and associate the link between the
periapical lesions in the maxillary teeth and maxillary sinus abnormalities (30).
Several authors have studied the diagnostic accuracy of CBCT for evaluating the
periapical bone tissue area and assessing post endodontic healing and pre-surgical
assessment. Lofthag-Hansen et al. 2007, have conducted a clinical study involving 46 teeth
(maxillary and mandibular) to compare CBCT and periapical film radiography (31). He
reported that CBCT showed 10 more teeth with periapical lesions compared to periapical
film. Estrela et al. 2008, found that CBCT had high sensitivity for detecting apical
periodontitis by comparing panoramic, periapical radiographs, and CBCT (32). Similarly,
another study assessed the difference between periapical radiography and CBCT in the
detection of periapical lesion in maxillary teeth for pre-surgical evaluation. The authors
reported that CBCT detected 34% more lesions than conventional radiography (33).
Others (19, 20, 34,35) have compared the accuracy of digital and CBCT for detecting
artificial apical bone defects in human mandibles. They proposed that CBCTs has better
accuracy than intraoral radiography, likely to find more cases of apical radiolucency as
13
compared to digital periapical radiography by laboratory studies. Moreover, Patel et al.
2009, conducted a study on human mandibles and concluded that CBCT resulted in
improved detection of presence or absence of a periapical lesion (4). CBCT have shown to
be more reliable in detecting peri-radicular radiolucencies than intraoral radiography (36).
Considering the advantages of accuracy and high sensitivity of CBCT, limitations still
exist. The presence of high density structures, such as amalgam, crowns, posts, filling
materials and others near the region of interest reduces the accuracy of the diagnostic image
of the CBCT because of the scattering and beam hardening that appears around these
structures (4,32,37). In addition, the use of CBCT, although useful, is higher than traditional
intraoral radiography in terms of radiation dose and cost of the imaging units (38).
Following the radiation safety principles of ALARA, the use of CBCT per year should be
limited (7).
To overcome the limitations produced by the 2D images when attempting to diagnose
periapical lesions, CBCT should be considered. In the classic study conducted by Goldman
et al., 1972, interpretation disagreement was evident when experienced examiners were
given 253 cases and asked to evaluate for the presence of periapical radiolucencies with
conventional radiographs. There was only 42.1% agreement among the evaluators (16).
Tewary et al. 2011, conducted a study with a similar protocols to test for reliability and
accuracy of interpreting digital radiographs, and reported that examiners were able to agree
only 25% of the time (17). It appears that both conventional and digital radiography have
some limitations in depicting actual anatomical and pathological structures.
The purpose of this study is to evaluate the intra-observer and inter-observer
agreement among 6 examiners evaluating digital periapical radiography and cone beam
14
computed tomography (17). Time needed to reach a radiographic interpretation was also
evaluated and compared.
15
3. Aims
The primary aim(s) of this study was:
• To evaluate the inter-rater reliability when evaluating digital periapical
radiographs compared to that of cone-beam computed tomography scans
(CBCT).
• To evaluate the intra-rater reliability when evaluating digital periapical
radiographs compared to that of cone-beam computed tomography scans
(CBCT).
The secondary aim of this study was:
• To report the time required to reach a diagnosis when interpreting a digital
periapical radiographs as compared to CBCT scans.
16
4. Materials and Methods
This study obtained ethical approval from the University Park Institutional Review Board
(UPIRB) designee was and is outlined in 45 CFR 46.101.
4.1 Sample Selection and Data Collection
The CBCT images and digital radiographs used in the study were taken during the
diagnostic and treatment planning phases, from patients referred to the University of
Southern California, Herman Ostrow School of Dentistry of Department of Endodontics for
dental treatment. The digital radiographs included were existing as part of the endodontic
survey, which includes three periapical radiographs and a bitewing, and the CBCTs scans of
the corresponding digital radiographs had already been requested for the management of
various complex endodontic conditions. A total of 359 scans were reviewed from the
database of the Endodontic clinic at the University of Southern California Herman Ostrow
School of Dentistry, between January 2013 and November 2016. Teeth selection was limited
to only molar teeth with previous root canal therapy, had a digital radiography examination,
with/without a periapical radiolucency, and with a widened periapical space. A total of 100
scans, 61 upper molars and 39 lower molars, with their corresponding digital radiographs
were collected by the primary investigator (endodontist) who did not participate in the
evaluation part of the study. The scans that were excluded in the study were those of anterior
teeth, premolars, and molar teeth with no previous root canal therapy performed (Figure 1.).
17
Figure 1. Study flow diagram showing the process of selection of records.
4.2 Data storage and Processing
The digital radiographs were taken according to the paralleling technique using the X-
ray unit Heliodent (Sirona, Bensheim, Germany) with digital charge-couple device sensors
(CCD) (Schick Technologies, New York, NY), and the limited-view CBCT images were
taken with Kodak 9000 3D System extra-oral imaging system FOV 50 x 37 mm at voxel
size 75 micrometer (Carestream Health, Rochester, NY). The radiographs and CBCT scans
were de-identified, so that no patient information is visible, and were stored in a folder that
359 scans were
reviewed from the
database of the
Endodontic clinic at
USC Ostrow School of
Dentistry
100 scans all molars
with previous root
canal therapy included
in analysis
Excluded Scans 259:
• Anterior teeth
• Premolars
• Molars without root
canal therapy
61 Upper Molars
39 Lower Molars
100 Digital Periapical
Radiographs corresponding
to the scans were included
in analysis
18
was only accessed by the primary investigator. A list of the 100 molar radiographs/CBCT
scans will only be available for the primary investigator. Only the primary investigator will
be able to relate the numbered radiographs/scans of the patients. Dell Workstations (Dell
Inc., Round Rock, Texas, USA) were used in the study with three different monitors to view
both types of the images. A 21.5 –inch Viewsonic (VX2233WM) monitors with a
resolution of 1920x1080, and a 19-inch Viewsonic (VP191b) monitor with a resolution
1280x1024 were used, both running with Windows 7 (Microsoft Corp, Redmond, WA,
USA). The digital radiographs were displayed using the Schick CDR Dicom 5.4 software,
and the scans were viewed with the CS 3D imaging software v3.3.9 (Carestream) using the
same monitors.
4.3 Image Viewing
A total of six observers participated in the study, two endodontists with more than 25
years of clinical experience, one radiologist with 15 years of clinical experience, and three-
second year endodontic residents with clinical experience that ranges between 5-15 years.
The observations were performed in separate sessions for each observer, where each
participant individually viewed both the CBCT scans and periapical images on the same
monitor, in the same room with the same lightening conditions. The presentation of both
types of images to the observers was randomized for each evaluator (six randomized
templates). All observers examined 100 periapical radiographs and then their corresponding
100 CBCT scans, or vice versa. They were asked to read the image and score “Yes”, “No”,
or “Uncertain”, regarding whether they see a periapical radiolucency of endodontic origin
confined to one of the roots of the molar tooth in the image. The evaluation was done twice,
where the same scans and digital images were re-examined by the same observers at a three-
19
month interval, which was an attempt to prevent the observers from recalling their previous
interpretations.
During both evaluation phases, each observer was able to manipulate the digital
images through the Schick software’s various enhancement properties such as contrast,
density, brightness, and sharpness. They were provided by the original CBCT data/scan and
were able to scroll through the entire 3D volume (axial, sagittal, and coronal slices of each
CBCT scan) keeping with the normal presentation of the CBCT in a clinical setting. They
also had full access to all of the software’s features, where they were able to manipulate the
images. No time limit was set for both evaluation sessions, and the time until each evaluator
made a decision for each image was recorded in each session.
The first session evaluation reading was used to determine the inter-rater agreement
analysis between the participants, and the second session readings were used for intra-rater
agreement analysis. The time recorded for each observer to reach a judgment was used to
compare the difference between the two types of diagnostic imaging.
4.4 Statistical Analysis:
The examiners’ score for the digital periapical radiograph (PR) and the cone-beam
computed tomography (CBCT) was recorded in Microsoft Excel (Microsoft Crop,
Redmond, WA) 2008 software, and then was subjected into further statistical analysis using
Stata 14.0 (College Station, TX).
Kappa was used to determine inter-rater reliability between the six raters at once. To
evaluate intra-rater reliability, the two readings from each rater were compared using the
Kappa coefficient to determine the extent to which each reader is consistent across readings
for both the PR and the CBCT. To assess the degree to which time is equivalent between the
20
two scanning methodologies, linear mixed models were used to assess the degree to which
time differs between the two scanning methods while taking into consideration repeated
measures by allowing for random effects for both the rater and the case. Additionally, we
selected several pairwise comparisons between raters a priori to assess possible effects of
experience level on agreement. These were: Rater 2 vs. Rater 3, Rater 6 vs. Rater 2 and
Rater 6 vs. Rater 3; Rater 4 vs. Rater 5, Rater 1 vs. Rater 5, and Rater 1 vs. Rater 5. The
residents were observer 2 and 3 and 6, and the faculty were 4, 5 and 1. Average loading time
was reported for CBCT and PR as a mean and standard deviation. A Bonferroni-corrected p-
value of .004 will be considered statistically significant.
Assuming a sample size of 100 scans and radiographic images, a two-sided
Bonferroni- corrected alpha level of 0.004, a kappa under the null hypothesis of 0.3 and
marginal frequencies between raters of 0.54 (yes), 0.45 (no) and 0.1 (uncertain), and for time
1; the calculated power of the sample was 81% power to detect a kappa of 0.50 or larger.
Power was calculate using PASS software, version 14.0 (Kayesville, UT).
Table 1: Interpretation of Kappa Statistic (38)
Kappa Value Interpretation
≤0 No agreement
0.01 – 0.20 None – Slight
0.21 – 0.40 Fair
0.41 – 0.60 Moderate
0.61 – 0.80 Substantial
0.81 – 1.00 Almost Perfect
21
5. Results
5.1 Inter-observer Reliability
Overall inter-rater reliability was in the fair range for PR and CBCT at baseline
and three months (Table 2). Specifically, inter-rater reliability was higher fair/moderate
for PR at baseline when considering to not take into account the uncertain score proposed
by all examiners; but when taken into account it ranged from 0.03 to 0.44, with a
combined Kappa of 0.30 (p<.001). Kappa for PR at three months showed a similar
pattern and range (0.04-0.44), with a combined Kappa of 0.35 (p<.001). The same
pattern of substantially lower agreement among equivocal results was seen for CBCT,
with ranges of 0.03-0.39 at baseline and 0.06-0.46 at three months. The combined Kappa
at baseline CBCT reading was 0.31 (p<.001) and 0.40 (p<.001) at the second reading
three months later. Percent agreement among examiners for PR was 55.6% and 59.7% at
baseline and three months, respectively. For CBCT, percent agreement was 59.5% at
baseline and 64.9% at three months.
Table 2: Inter-rater reliability (Agreement) between six raters for periapical radiographs
(PR) and cone beam computed tomography (CBCT)
Variable Kappa P-value
PR – Baseline
No 0.32 <.001
Yes 0.44 <.001
Uncertain 0.03 0.22
Combined 0.30 <.001
PR – 3 Months
No 0.38 <.001
Yes 0.44 <.001
Uncertain 0.04 0.06
Combined 0.35 <.001
CBCT – Baseline
No 0.33 <.001
22
Yes 0.39 <.001
Uncertain 0.03 0.10
Combined 0.31 <.001
CBCT – 3 Months
No 0.44 <.001
Yes 0.46 <.001
Uncertain 0.06 0.01
Combined 0.40 <.001
5.2 Intra-observer Reliability
Intra-rater reliability was greater than chance for all six raters, suggesting that
each rater showed moderate to good agreement within rater for both PR and CBCT (Table
3). Specifically, The Kappa for PR ranged from 0.38 to 0.63 (p<.001 for all) and between
0.40 to 0.64 for CBCT (p<.001 for all). There was similar degree of agreement for both
PR and CBCT.
Table 3. Intra-rater reliability (Agreement) for each observer for periapical radiography
(PR) and cone-beam computed tomography (CBCT)
Rater Kappa % Agreement P-value
Rater 1
PR 0.63 83% <.001
CBCT 0.64 82% <.001
Rater 2
PR 0.63 81% <.001
CBCT 0.41 72% <.001
Rater 3
PR 0.38 59% <.001
CBCT 0.47 72% <.001
Rater 4
PR 0.44 67% <.001
CBCT 0.44 70% <.001
23
Rater 5
PR 0.50 66% <.001
CBCT 0.40 63% <.001
Rater 6
PR 0.40 65% <.001
CBCT 0.43 67% <.001
The measure of agreement between PR and CBCT was also calculated. At
baseline, the agreement between CBCT and PR was found to be K=0.29 (% percentage of
agreement = 57%, P<0.001). At 3 months there was a slight improvement, and the
agreement between CBCT and PR was found to be K=0.34 (% percentage of agreement =
61.5%, P<0.001). This kappa analysis indicates that the level of agreement between
CBCT and PR was in the fair range.
5.3 Observation time
When evaluating observation time between CBCT and PR, we found that both at
baseline and at three months, CBCT scans required additional reading time compared to
PR scans. Specifically, at baseline, it required 67 seconds longer to read CBCT scans
than to read PR scans (95% CI: 62.3, 71.6, p<0.001); while at three months, it required an
additional 42.6 seconds (95% CI: 39.6, 45.6, p<0.001) to read CBCT than PR scans
(Table 4).
24
Table 4. Difference in the reading time between the digital periapical radiographs (PR)
and cone-beam computed tomography scans (CBCT)
Variable Mean ± SD Beta 95% CI P-value
Time at
Baseline
PR 23.6 ±15.2 Referent --
CBCT 90.6 ± 60.0 67.0 62.3, 71.6 <.001
Time at 3
Months
PR 25.0 ± 16.9 Referent --
CBCT 67.6 ± 34.6 42.6 39.6, 45.6 <.001
Figure 2: Periapical Radiograph (PR) Time by Rater at First Reading
0 50 100 150
PR Time (seconds)
1 2 3 4 5 6
25
Figure 3: Cone Beam Computed Tomography (CBCT) Time by Rater at First Reading
Figure 4: Periapical Radiograph (PR) Time by Rater at Second Reading
0 100 200 300 400
CBCT Time (seconds)
1 2 3 4 5 6
0 20 40 60 80 100
PR Time (seconds)
1 2 3 4 5 6
26
Figure 5: Cone Beam Computed Tomography (CBCT) Time by Rater at Second Reading
5.4 Inter-observer Agreement by Level of Experience
We also calculated agreement using kappa statistics stratifying by level of
experience (faculty vs. resident) (Table 5). There were statistically significant deviations
from chance agreement for residents and faculty members for both PR and CBCT at
both time points (Table 5). Kappa statistics were all within the fair range (0.26 to 0.40,
p<.001 for all), with only slightly higher values observed among faculty than among
residents. Both groups showed slightly more agreement at the three-month time point
than at baseline for PR and CBCT.
0 50 100 150 200
CBCT Time (seconds)
1 2 3 4 5 6
27
Table 5: Combined inter-rater agreement for digital periapical radiographs (PR) and cone
beam tomography (CBCT) by level of experience
Rater Kappa P-value
Residents
a
PR: Baseline 0.26 <.001
CBCT: Baseline 0.27 <.001
PR: 3 Months 0.33 <.001
CBCT: 3 Months 0.37 <.001
Faculty
a
PR: Baseline 0.28 <.001
CBCT: Baseline 0.34 <.001
PR: 3 Months 0.35 <.001
CBCT: 3 Months 0.40 <.001
The resident group includes raters 2, 3 and 6; the faculty group includes raters 1, 4 and 5. PR= periapical
radiographs; CBCT= cone beam computed tomography
To further analyze the raters in each group, pairwise inter-observer agreement was
assessed between selected participants in each group (Table 6). When comparing raters
within experience levels (i.e., comparing faculty members or residents to one another),
we find similar values for comparisons between faculty as those between residents (Table
6). Kappa values for faculty range between 0.25 and 0.45 (p<.001 for all), indicating fair
agreement. Similarly, kappa values for residents also indicate fair agreement and range
from 0.20 to 0.40 (p<.001 for all).
Table 6: Pairwise inter-rater agreement amongst faculty and resident subgroups
a
for
digital periapical radiographs (PR) and cone beam computed tomography (CBCT)
Variable %
Agreement
Kappa P-value
Baseline PR
Faculty
Rater 1 vs. Rater 4 70% 0.44 <.001
Rater 1 vs. Rater 5 47.5% 0.25 <.001
Rater 4 vs. Rater 5 44.5% 0.25 <.001
Residents
Rater 2 vs. Rater 3 56.3% 0.30 <.001
Rater 2 vs. Rater 6 58.3% 0.29 <.001
Rater 3 vs. Rater 6 53.0% 0.25 <.001
Three Months PR
Faculty
28
Rater 1 vs. Rater 4 63% 0.33 <.001
Rater 1 vs. Rater 5 62.3% 0.36 <.001
Rater 4 vs. Rater 5 59.6% 0.35 <.001
Residents
Rater 2 vs. Rater 3 53.1% 0.27 <.001
Rater 2 vs. Rater 6 66.7% 0.38 <.001
Rater 3 vs. Rater 6 60% 0.38 <.001
Baseline CBCT
Faculty
Rater 1 vs. Rater 4 68% 0.41 <.001
Rater 1 vs. Rater 5 61.6% 0.35 <.001
Rater 4 vs. Rater 5 58.6% 0.30 <.001
Residents
Rater 2 vs. Rater 3 61.5% 0.26 <.001
Rater 2 vs. Rater 6 64.6% 0.37 <.001
Rater 3 vs. Rater 6 58% 0.20 <.001
Three Months CBCT
Faculty
Rater 1 vs. Rater 4 71% 0.45 <.001
Rater 1 vs. Rater 5 65.7% 0.39 <.001
Rater 4 vs. Rater 5 64.7% 0.37 <.001
Residents
Rater 2 vs. Rater 3 67.7% 0.37 <.001
Rater 2 vs. Rater 6 68.8% 0.40 <.001
Rater 3 vs. Rater 6 62% 0.36 <.001
a
Raters 2, 3 and 6 were residents while raters 1, 4 and 5 were faculty members.
When stratifying by whether the tooth is located in the upper or lower jaw, we
found that levels of agreement were slightly higher among those teeth located in the
lower jaw (Table 7). While Kappa values ranged from 0.24 to 0.33 (p<.001 for all)
among teeth in the upper jaw, Kappa statistics among scans taken from teeth in the lower
jaw ranged from 0.38 to 0.48 (p<.001 for all).
Table 7: Combined inter-rater agreement for digital periapical radiographs (PR) and cone
beam tomography (CBCT) by tooth location (Upper or Lower)
Rater Kappa P-value
Upper
a
29
PR: Baseline 0.24 <.001
CBCT: Baseline 0.26 <.001
PR: 3 Months 0.30 <.001
CBCT: 3 Months 0.33 <.001
Lower
a
PR: Baseline 0.40 <.001
CBCT: Baseline 0.38 <.001
PR: 3 Months 0.40 <.001
CBCT: 3 Months 0.48 <.001
a
Upper teeth included tooth numbers 17, 18, 19, 30 & 31. Lower teeth included tooth
numbers 2, 3 14 and 15.
30
6. Discussion
To our knowledge, endodontic diagnosis is made after the assessment of the overall disease
status, through gathering information from clinical symptoms and reading the radiographs.
Evidence has shown that interpreting the radiographic images among clinicians is highly variable
(16). The purpose of the present study is to determine the inter-operator and intra-operator
reliability when evaluating the interpretation of the same image using two different imaging
modalities, digital periapical radiographs and cone-beam computed tomography scans; and the time
required to reach a radiographic interpretation when viewing the different images. Assessing the
knowledge of this study will allows us understand how well we use our radiographic imaging
systems in the diagnosis process.
In the present study, six observers viewed 100 digital periapical radiographs (PR)
and their corresponding100 cone-beam computed tomographic scans (CBCT), and made
their interpretations. The design of the study was made in an attempt to simulate a clinical
environment. Each observer had no time limit set during the evaluation process and was able
to use both the PR and CBCT software with no restrictions. The observers were not
calibrated to any scale in an attempt to closely associate with a regular clinical setting,
depending on each observer’s interpretation and scale of what a periapical radiolucency of
endodontic origin is on an image. If observers were calibrated this would probably have
improved the interpretation agreement, however it would not simulate the clinical settings.
This sheds light on the strength of the study, because it was designed to reflect the
diagnostic process in most dental offices. The sample size of the study was 100, and the
calculated power of the sample was 81% power (a kappa of 0.50 or larger) to detect the
31
difference in interpretation scores between the six observers. The sample size chosen
because of the strict inclusion criteria with only molar teeth included, we believe that adding
different teeth groups would have affected the interpretation of the data.
The results of the study show that in the assessment of the inter-observer agreement
when evaluating the PR and the CBCT in the first and second session was fair to moderate,
among the 6 observers. These results confirm those of previous studies (16,17) that
interpreting radiographic images is highly variable. They reported the inter-rater reliability
as a percentage of agreement found to be 47% by Goldman’s study (16), and less than 25%
by Tewary’s study (17); considered to be fair agreement. The results of our study suggest
that inter-rater reliability was fair amongst the six raters, meaning there was some agreement
among them using both imaging modalities. The possible reason for such fair inter-rater
reliability is the diverse background of the examiners, where each had his own definition of
what a peri-apical radioluceny appear on a radiographic image/scan; showing that the
radiographic interpretation disagreement maybe happening in a clinical situation.
Upon reading the 100 radiographs and 100 scans, our results showed the intra-
observer reliability was in the moderate kappa range. Our examiners were able to agree with
themselves when using both the PR and CBCT. The Kappa for PR and CBCT ranged from
0.38 to 0.63 and 0.40 to 0.64, respectively; with the p value of p<0.001, indicating moderate
observed agreement. This repeatability compared with previous studies appears to be better,
but still not perfect. The reported results from Tewary’s study for the intra-rater agreement
ranged from 41%-85% (17), for the digital radiography, which was in close agreement with
our results 59%-83%. In addition , our results were comparable to those reported by
Goldman et al 1974, which were 74%-80% (16). Moreover, the agreement achieved by the
32
CBCT scans ranged between 63% - 82%; which can be considered in the same range as
those of digital radiography. These results reflect that the six examiners were consistent with
their responses and in their minds had a their own definition of what they were viewing.
This does not mean that what they were reading correlates with true interpretation of the
image.
The time it took each examiner to finalize his decision about the image being viewed
was also analyzed in our study. In the first reading session, it took 67 seconds longer to read
a CBCT scan compared to the second session which required 42.6 seconds only. These
values shows reading a CBCT takes longer but such time is minimal when arguing that
interpreting a CBCT takes longer time during the diagnosis process. For optimum patient
care, regardless of the time needed to reach a diagnosis it is crucial to avoid mistakes when
managing endodontic problems. however, this low time reflects only the interpretation of a
focused area od interest, which was molars only, and that maybe different when looking at a
whole scan of either a mandible or a maxilla.
Considering the low level of inter-rater reliability obtained from our study, the
different level of experience of the examiners was analyzed to see if this factor effects the
interpretation. The impact of the clinical level of experience on the inter-rater reliability
showed fair agreement. Based on our analysis, the strategy of experience does not play a
role on radiographic interpretation, as the data obtained was very low. Our results are not
different in comparison with a previous study conducted to assess the variability between
observers in detecting periapical lesions. They concluded that there is a correlation between
the level of experience among clinicians and the ability to detect a disease on a CBCT,
however agreement between the groups was not excellent (39). Many factors can be related
33
to the interpretation process, however we hypothesize that other factors may have impacted
the interpretation.
Although the scientific yield from this study is significant, the study is not without
limitations. Interpretation of radiography regardless of the system used, remain a subjective
matter. In addition, factors related to the operators’ familiarity with the digital system, and
the radiographic index used by observers when assessing any radiographic image pose
further limitations to this study. However, reasons for variability in the study can be
reasoned by the heterogeneity of the participants. Also, the training backgrounds of the
examiners, the different places they have been previously working in, their biases, education
and training all might have impacted their interpretation. We hypothesize that the
technology itself, digital radiography and cone-beam computed tomography, is limiting us
from calling things what they really are. Further studies are needed to assess these effects,
and the scientific development of how to improve the diagnostic interpretation is needed.
More evidence-based research is needed to better understand how to interpret a scan
reliably.
34
7. Conclusion
It is well documented that the interpretation of the radiographs has long been a
subjective matter. This study has revealed that reading an image in the diagnostic process
of endodontic therapy is still a subjective matter. Cone-beam computed tomography
interpretation is not far from the digital radiographic method, and not better, when
reading the periapical tissue status of molar teeth. The examiners in the study can
reliably reproduce their own results, and they were showed fair agreement with each
other when compared. Interpreting radiographic images and being able to identify
periapical changes is an important part of dentists’ daily practice. Correct interpretation
of such images will ensure a better diagnosis and treatment decision-making. High
reliability of interpreting different types of radiographic images will minimize miss-
diagnosis and unnecessary treatment. Also, the amount of time invested in reading a
digital radiograph or a cone-beam tomographic scan is of potential value for
time management in the dental practice. More research is needed to educate and ensure
that clinicians that are likely to use the CBCT modality in their practices are not mis-
using this technology.
35
8. References
1) Soh G, Loh PC, Chong YH. Radiation dosage of a dental imaging system. Quint Int
1993;24:189-91.
2) Bender IB, Seltzer S. Roentgenographic and direct observation of experimental
lesions in bone: part 1. J Am Dent Assoc 1961;62:152-60.
3) Goldman M, Pearson AH, Darzenta N. Endodontic Success – Who’s reading the
radiograph? Oral Surg Oral Med Oral Pathol 1972;33:432-7.
4) Patel S. New Dimensions in endodontic imaging: Part 2. Cone beam computed
tomography. Int Endod J 2009;42:463-75.
5) Parashar V, Whaites E, Monsour P, et al. Cone beam computed tomography in dental
education: A survey of U.S., U.K., and Australian dental schools. J Dent Educ 2012;
76:1443-7.
6) Reit C, Grondahl HG. Endodontic retreatment decision making among a group of
general practitioners. Scand J Dent Res 1988;96:112-7.
7) Joint position statement of the American Association of Endodontics and the
American Academy of Oral and Maxillofacial Radiology. Use of cone beam
computed tomography in endodontics. Oral Surg Oral Med Oral Pathol Oral Radio
Endod 2015;120:508-12.
8) Mozzo P, Procacci C. A new volumetric CT machine for dental imaging based on
cone beam technique: preliminary results. Eur Radiol 1998;8:1558-64.
9) Arai Y, Tammisalo E, Iwai K, Hashimoto K, Shinoda K. Development of a compact
computed tomographic apparatus for dental use. Dentomaxillofac Radiol 1999;
28:245-48.
10) Patel S, Dawood A, Mannocci F, et al. Detection of periapical bone defects in human
jaws using cone beam computed tomography and intraoral radiography. Int Endod J
2009;42:507-15.
11) Scarfe WC, Levin MD, Gane D, et al. Uses of cone beam computed tomography in
endodontics. Int Endod J 2009;1-20.
12) Cotton TP, Geisler TM, Holden DT, et al. Endodontic applications of cone-beam
36
volumetric tomography. J Endod 2007;33:1121-32.
13) Schulze R, Heil U, Gross E, et al. Atefacts in CBCT: a review. Dentomaxillofac
Radiol 2011;40:265-73.
14) Ludlow JB. Dosimetry of the Kodak 9000 3D Small FOV CBCT and Panoramic
Unit. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;107: e2
15) Rohlin M, Kullendorff B, Ahlqwist M, et al. Observer performance in the assessment
of periapical pathology: a comparison of panoramic with periapical radiography.
Dentomaxillofac Radiol 1991;20:127-31.
16) Goldman M, Pearson AH, Darzenta N. Reliability of radiographic interpretations.
Oral Surg Oral Med Oral Pathol 1974;38:287–93.
17) Tewary S, Luzzo J, Hartwell G. Endodontic Radiography: Who is reading the digital
radiograph? J Endod 2011;37:919-21.
18) Mistak EJ, Loushine RJ, Primack PD, et al. Interpretation of periapical lesions
comparing conventional, direct digital, and telephonically transmitted radiographic
images. J Endod 1998;24:262-24.
19) Folk RB, Thorpe JR, McClanahan SB, et al. Comparison of two different direct
digital radiography systems for the ability to detect artificially prepared periapical
lesions. J Endod 2005;31:304-06.
20) Velvart P, Hecker H, Tillinger G. Detection of the apical lesion and the mandibular
canal in conventional radiography and computed tomography. Oral Surg Oral Med
Oral Pathol Oral Radiol Endod 2001;92:682-8.
21) Huumonen S, Orstavik D. Radiological aspects of apical periodontitis. Endod Topics
2002;1:3-25.
22) Barbat J, Messer HH. Detectability of artificial periapical lesions using direct digital
and conventional radiography. J Endod 1998;24:837-42.
23) Lee RJ, Weissheimer A, Pham J, et al. Three-dimensional monitoring of root
movement during orthodontic treatmen. Am J Orthod Dentofacial Orthop
2015;147:132-42.
24) Tong H, Enciso R, Van Elslande D, et al. A new method to measure mesiodistal
angulation and faciolingual inclination of each whole tooth with volumetric cone-
beam computed tomography images. Am J Orthod Dentofacial Orthop
2012;142:133-43.
37
25) Von Arx T, Jensen SS, Bornstein MM. Changes of root length and root-to-crown
ratio after apical surgery: An analysis by using cone-beam computed tomography. J
Endod 2015; 41:1424-29.
26) Matherne RP, Angelopoulos C, Kulild JC, et al. Use of cone-beam computed
tomography to identify root canal systems in vitro. J Endod 2008;34:87–9.
27) Cohenca N, Simon JH, Mathur A, et al. Clinical indications for digital imaging in
dento-alveolar trauma—part 2: root resorption. Dent Traum 2007;23:105–13.
28) Simon JH, Enciso R, Malfaz J-M, et al. Differential diagnosis of large periapical
lesions using cone-beam computed tomography measurement and biopsy. J Endod
2006;32:833-7.
29) Talwar S, Uteneja S, Nawal RR, et al. Role of cone-beam computed tomography in
diagnosis of vertical root fractures: A systematic review and meta-analysis. J Endod
2016;42:12-24.
30) Nunes C, Guedes OA, Alencar AHG, et al. Evaluation of periapical lesions and their
association with axillary sinus abnormalities on cone-beam computed tomographic
images. J Endod 2016;42:42-6.
31) Lofthag-Hansen S, Huumonen S, Grondahl K, et al. Limited cone-beam CT and
intraoral radiography for the diagnosis of periapical pathology. Oral Surg Oral Med
Oral Pathol Oral Radiol Endod 2007;103:114–9.
32) Estrela C, Bueno MR, Leles CR, et al. Accuracy of Cone Beam Computed
Tomography and panoramic and periapical radiography for detection of apical
periodontitis. J Endod 2008;34:273–79.
33) Low MTL, Dula KD, Burin W, et al. Comparison of periapical radiography and
limited cone-beam tomography in posterior teeth referred for apical surgery. J Endod
2008;34:557-62.
34) Venskutonis T. Daugela P, Strazdas M, et al. Accuracy of digital radiography and
Cone Beam Computed Tomography on periapical radiolucency detection in
endodontically treated teeth. J Oral Maxillofac Res 2014;5(2):e1
35) Christiansen R, Kirkevang LL, Gotfredsen E, et al. Periapical radiography and cone
beam computed tomography for assessment of the periapical bone defect 1 week and
12 months after root-end resection. Dent Maxillofac Radiol 2009;38:531-6.
36) Lennon S, Patel S, Foschi F, et al. Diagnostic accuracy of limited-volume cone-beam
38
computed tomography in the detection of periapical bone loss: 360 degrees scans
versus 180 degrees scans. Int Endod J 2011;44:1118–27.
37) Demiralp KO, Kamburŏglu K, Güngr K, et al. Assessment of endodontically treated
teeth by using different radiographic methods: an ex vivo comparison between
CBCT and other radiographic techniques. Imaging Sci Dent 2012;42:129-37.
38) Roberts JA, Drage NA, Davies J, et al. Effective dose from cone beam CT
examinations in dentistry. Br J Radiol 2009;82:35-40.
39) Parker J, Mole A, Rivera E, et al. Cone-beam computed tomography in clinical
endodontics: Observer variability in detecting periapical lesion. J Endod
2017;43:184-7.
McHugh ML. Interrater reliability: the kappa statistic. Biochem Med (Zagreb).
2012;22(3):276-8
Abstract (if available)
Abstract
Aims. To evaluate the inter-rater reliability and intra-rater reliability when evaluating digital periapical radiographic (PR) images compared to that of cone-beam computed tomography scans (CBCT). ❧ Materials and Methods. 6 observers including 3 endodontists, 3 second year endodontic residents, and 1 radiologist independently evaluated 100 molar digital radiographs and 100 CBCT scans to determine the presence of a periapical radiolucency of endodontic origin and scored either: “yes”, “No”, or “Uncertain”. Each examiner was able to use all of the software enhancement tools and had full access to the software’s features. All six observers re-examined the same digital images and scans 3 months later. No time limit was set for both evaluation sessions, and the time until each evaluator made a decision for each image was recorded in each session. The data were analyzed to determine the inter-examiner and intra-examiner agreement. Linear mixed models were used to determine the time taken to evaluate each modality. ❧ Results. Kappa for inter-rater reliability in the first observation session for periapical radiography ranged from 0.03 to 0.44, combined K= 0.30 (p<.001) and at three months showed a similar pattern and range (0.04-0.44), with a combined Kappa of 0.35 (p<.001), suggesting fair agreement. Kappa in the first session for CBCT ranged 0.03-0.39 and 0.06-0.46 at three months. The combined Kappa at baseline CBCT reading was 0.31 (p<.001) and 0.40 (p<.001) at the second reading three months later
Linked assets
University of Southern California Dissertations and Theses
Conceptually similar
PDF
Cone-beam computed tomography images: applications in endodontics
PDF
Mental foramina variations: a retrospective analysis using cone-beam computed tomography
PDF
Comparison of HLD CAL-MOD scores obtained from digital versus plaster models
PDF
Detrimental effects of dental encroachment on secondary alveolar bone graft outcomes in the treatment of patients with cleft lip and palate: a cone-beam computed tomography study
PDF
Maxillary sinus floor and alveolar crest alterations following extraction of maxillary molars: a retrospective CBCT analysis
PDF
The effect of cone beam computed tomography (CBCT) imaging on orthodontic diagnosis and treatment planning
PDF
Three-dimensional assessment of tooth root shape and root movement after orthodontic treatment: a retrospective cone-beam computed tomography study
PDF
Cone beam computed tomographic measurements of buccal alveolar bone widths overlying the maxillary premolars
PDF
Comparison of facial midline landmark and condylar position changes following orthognathic surgery
PDF
Prevalence of TMJ morphological changes and scoring system based on CBCT imaging
PDF
Maxillary sinus floor and alveolar crest alterations following extraction of maxillary molars and ridge preservation: a retrospective CBCT analysis
PDF
An assessment of orthognathic surgery outcomes utilizing virtual surgical planning and a patented full-coverage 3D-printed orthognathic splint
PDF
Dimensional changes in alveolar bone following extraction of maxillary molars in humans: a retrospective CBCT analysis
PDF
Classification of 3D maxillary incisor root shape
PDF
A cone beam-CT evaluation of the availability of space for complete arch retraction in the mandible with TADs
PDF
The effect of vertical level discrepancy of adjacent dental implants on crestal bone resorption: a retrospective radiographic analysis
PDF
A randomized controlled clinical trial evaluating the efficacy of grafting the facial gap at immediately placed implants in the anterior maxilla: 3D analysis of bone and soft tissue changes
PDF
Prevalence and distribution of facial alveolar bone fenestrations in the anterior dentition: a cone beam computed tomography analysis
PDF
The mesiodistal angulation and faciolingual inclination of each whole tooth in three dimensional space post non-extraction orthodontic treatment
PDF
Influence of a novel self-etching primer on bond-strength to glass-ceramics and wettability of glass-ceramics
Asset Metadata
Creator
Badran, Yassmin
(author)
Core Title
Who is reading the digital radiography and the cone beam computed tomography?
School
School of Dentistry
Degree
Master of Science
Degree Program
Craniofacial Biology
Publication Date
07/24/2017
Defense Date
05/25/2017
Publisher
University of Southern California
(original),
University of Southern California. Libraries
(digital)
Tag
cbct,digital radiography,OAI-PMH Harvest,reliability
Format
application/pdf
(imt)
Language
English
Contributor
Electronically uploaded by the author
(provenance)
Advisor
Roges, Rafael (
committee chair
)
Creator Email
badran103@gmail.com,ybadran@usc.edu
Permanent Link (DOI)
https://doi.org/10.25549/usctheses-c40-410277
Unique identifier
UC11214784
Identifier
etd-BadranYass-5605.pdf (filename),usctheses-c40-410277 (legacy record id)
Legacy Identifier
etd-BadranYass-5605.pdf
Dmrecord
410277
Document Type
Dissertation
Format
application/pdf (imt)
Rights
Badran, Yassmin
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
Tags
cbct
digital radiography
reliability