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The correlation between dental caries in primary and permanent teeth in children at two different elementary schools
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The correlation between dental caries in primary and permanent teeth in children at two different elementary schools
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Content
THE CORRELATION BETWEEN DENTAL CARIES IN PRIMARY AND
PERMANENT TEETH IN CHILDREN AT TWO DIFFERENT ELEMENTARY
SCHOOLS
by
Howard Hyung-won Kim
A Thesis Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
MASTER OF SCIENCE
(CRANIOFACIAL BIOLOGY)
May 2009
Copyright 2009 Howard Hyung-won Kim
ii
Dedication
To my family:
Jongtae John Kim
Mija Jennifer Kim
iii
Acknowledgments
A special thank you to:
Dr. Paul Denny
Dr. Glenn Sameshima
Dr. Michael Paine
Dr. Joyce Galligan
Patricia Denny
Jona Takashima
iv
Table of Contents
Dedication ii
Acknowledgements iii
List of Tables v
List of Figures viii
Abstract ix
Chapter 1: Introduction 1
Chapter 2: Literature Review 3
Chapter 3: Hypotheses 6
Chapter 4: Materials and Methods 8
Chapter 5: Results 13
Chapter 6: Assumptions 32
Chapter 7: Limitations 33
Chapter 8: Discussion 34
Chapter 9: Conclusion 39
Bibliography 40
v
List of Tables
TABLE 1: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old 16
Griffin and Rossmoor dft/t Scores
TABLE 2: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old 17
Griffin and Rossmoor dft/t Scores
TABLE 3: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old 17
Griffin and Rossmoor dft/t Scores
TABLE 4: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old 17
Griffin and Rossmoor dft/t Scores
TABLE 5: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old 18
Griffin and Rossmoor DFT/T Scores
TABLE 6: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old 18
Griffin and Rossmoor DFT/T Scores
TABLE 7: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old 19
Griffin and Rossmoor DFT/T Scores
TABLE 8: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old 19
Griffin and Rossmoor DFT/T Scores
TABLE 9: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old 20
Rossmoor Male and Female dft/t Scores
TABLE 10: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old 20
Rossmoor Male and Female dft/t Scores
TABLE 11: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old 21
Rossmoor Male and Female dft/t Scores
TABLE 12: Data Used for Unpaired t-test on 10 Year Old Rossmoor Male 21
and Female dft/t Scores
TABLE 13: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old 22
Rossmoor Male and Female DFT/T Scores
TABLE 14: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old 22
Rossmoor Male and Female DFT/T Scores
vi
TABLE 15: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old 22
Rossmoor Male and Female DFT/T Scores
TABLE 16: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old 23
Rossmoor Male and Female DFT/T Scores
TABLE 17: Data Used for Unpaired t-test on 7 Year Old Griffin Male 23
and Female dft/t Scores
TABLE 18: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old 24
Griffin Male and Female dft/t Scores
TABLE 19: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old 24
Griffin Male and Female dft/t Scores
TABLE 20: Data Used for Unpaired t-test on 10 Year Old Griffin Male 25
and Female dft/t Scores
TABLE 21: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old 25
Griffin Male and Female DFT/T Scores
TABLE 22: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old 26
Griffin Male and Female DFT/T Scores
TABLE 23: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old 26
Griffin Male and Female DFT/T Scores
TABLE 24: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old 26
Griffin Male and Female DFT/T Scores
TABLE 25: Data Used for Unpaired t-test on 7 Year Old Griffin Asian 27
and Hispanic dft/t Scores
TABLE 26: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old 27
Griffin Asian and Hispanic dft/t Scores
TABLE 27: Data Used for Unpaired t-test on 9 Year Old Griffin Asian 28
and Hispanic dft/t Scores
TABLE 28: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old 28
Griffin Asian and Hispanic dft/t Scores
TABLE 29: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old 29
Griffin Asian and Hispanic DFT/T Scores
vii
TABLE 30: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old 29
Griffin Asian and Hispanic DFT/T Scores
TABLE 31: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old 30
Griffin Asian and Hispanic DFT/T Scores
TABLE 32: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old 30
Griffin Asian and Hispanic DFT/T Scores
viii
List of Figures
FIGURE 1: Breakdown of Students at Griffin and Rossmoor Elementary 9
FIGURE 2: Linear Regression and Equation for Griffin Elementary Children 13
FIGURE 3: Linear Regression and Equation for Rossmoor Elementary Children 15
FIGURE 4: Bar Charts of Average dft/t and DFT/T Ratios for All Griffin and 31
Rossmoor Elementary Children
ix
Abstract
Introduction: High caries prevalence in children is a major oral health issue. Few studies
about dental caries have been conducted on children with mixed dentitions (presence of
both primary and permanent teeth). Specific information is needed validating the
correlation between caries in primary and permanent
teeth in the same child. Methods:
Dental caries patterns were assessed for children 7 to 10 years old from two different
elementary schools. Linear regression analysis was used to determine whether the
presence of caries in the primary teeth significantly correlated with caries in the
permanent teeth. Results: The study found significant correlations between caries
in
primary and permanent dentitions (p < 0.05). The highest correlation was found among 7
year old children at one elementary school (r = .805, p < 0.001). Conclusions: Decay on
primary teeth should be a risk indicator for caries in permanent teeth.
1
Chapter 1: Introduction
Dental caries was the most common disease among 5 to 17 year olds (National
Center for Health Statistics, 1996). Dental caries had a higher percentage of incidences
among 5 to 17 year olds than asthma, hay fever, and chronic bronchitis combined.
Furthermore, prevalence of dental caries is age-dependent; fewer children, age 12 to 17
years, were caries-free than children age 5 to 11 years (32.7% vs. 74.0%) (Brown et al.,
1996). Therefore, high caries prevalence in children is a major oral health issue.
Previous studies have analyzed caries risk predictors, including salivary buffer
capacity and flow rate (Alaluusua et al., 1990), sucrose intake
frequency (Llena and
Forner, 2008), and past caries experience (vanPalenstein Helderman et al., 2001; Seppä et
al, 1989). Most of these studies, however,
consisted of a cross-sectional analysis or a
single survey. Specific information is needed validating the correlation between caries in
primary and permanent
dentitions of the same individuals in consecutive years. In order
to obtain this information, this study evaluated children from two elementary schools
(Griffin Elementary and Rossmoor Elementary). The amount of decay and filled teeth on
primary teeth was measured by the dft/t ratio; the amount of decay and filled teeth on
permanent teeth was measured by the DFT/T ratio.
Using these ratios, the purpose of this study was to determine whether decay on
primary teeth correlates
with decay on permanent teeth in the same individual. This study
tests the hypothesis that presence of caries in the primary teeth significantly correlates
with caries in the permanent teeth. This study also examined whether there was a
significant difference in the dft/t and DFT/T ratios between two different schools (Griffin
2
and Rossmoor Elementary schools), between sexes (males and females), and between
ethnicities (Asians and Hispanics).
3
Chapter 2: Literature Review
The potential times for dental caries to develop vary between primary and
permanent dentitions as does the range of interrelated factors acting in the caries process
(Eriksen and Dimitrov, 2003). This makes the stability needed for prediction extremely
difficult. Within these limitations, past caries experience remains the most powerful
predictor of future caries in the young permanent dentition (Powell, 1998; Demers et al,
1989).
However, many of the previous studies about dental caries suffer from obvious
methodical weaknesses. Retrospective study designs are common. Retrospective studies
take baseline data that have been obtained from previous records. In these cases,
reliability might be questioned because prior inter-examiner calibration is usually
lacking. By contrast, prospective studies usually allow the same diagnostic methods to be
used. They may also include calibration training programs and the same caries criteria
may be used both at baseline and at endpoint examinations. Therefore, prospective study
designs are preferred, either when the focus is to look for caries associations between
primary and permanent teeth or to identify children who might be at risk for dental caries
in the future (Skeie et al., 2001).
The diagnostic method chosen should be based on the current scientific
knowledge that dental caries is a complex multifactorial disease, resulting from a
disturbance in the balance between teeth and existing oral flora present in biofilms.
Dental caries result from an ecological shift in the tooth-surface biofilm which leads to a
mineral imbalance and to a net loss of tooth mineral. Dental caries belong to a category
of common diseases, such as cancer and diabetes, in which many genetic, environmental
4
and behavioral risk factors interact (Fejerskov, 2004). Furthermore, it may be concluded
from past research that not only is the identification of high caries-risk individuals
important in itself, but the identification of these children can help prevent them from
receiving invasive restorative dental treatment in the future.
In order to avoid costly dental treatment, many studies have been conducted to
identify caries risk predictors. A literature review of caries risk predictors was done
(Powell 1998). The conclusions to this literature review on caries prediction were:
● Clinical variables, especially past caries experience, have been confirmed as the
most significant predictors of future caries development.
● The status of the most recently erupted/exposed surface is the most appropriate
measure of past caries experience.
● Bacterial levels are included in the most accurate prediction models.
● Sociodemographic variables are most important to prediction models for young
children and older adults.
In one particular study, an eight-year cohort study analyzed Chinese children and
the study found statistically significant associations between caries prevalence in primary
and permanent dentitions (p < 0.01) (Li and Wang, 2002). Furthermore, high caries
prevalence and more decayed teeth were observed in the primary dentition of children
with lower socio-economic status. The socio-economic status may not indicate a direct
etiologic risk factor for dental caries, but it can significantly undermine tooth
susceptibility for caries in primary teeth (Li and Wang, 2002).
In another study, a sample of 186 children (90 males) living in Norway were
clinically examined as 5 year olds and re-examined as 10 year olds by calibrated dentists
5
(Skeie et al., 2001). Statistically significant correlations were found between the caries
experience in the two dentitions as well as between the primary second molars at baseline
and the permanent teeth at 10 years of age. More than two surfaces with caries experience
in primary second molars were suggested as a clinically useful predictor at 5 years of age
for being at high risk at age 10.
All in all, there are plenty of research articles that have been done linking primary
and permanent caries. However, none of the previous studies have used the dft/t and
DFT/T ratios as criteria for measuring the association between primary and permanent
decay.
6
Chapter 3: Hypotheses
Research Hypotheses
1. There is a significant correlation and linear regression between dft/t and DFT/T.
2. There is a significant difference in the number of dental caries on primary teeth and
history of caries on primary teeth (measured by the dft/t ratio) between Griffin and
Rossmoor Elementary children.
3. There is a significant difference in number of dental caries on permanent teeth and
history of caries on permanent teeth (measured by the DFT/T ratio) between Griffin and
Rossmoor Elementary children.
4. There is a significant difference in dft/t ratios between male and female children.
5. There is a significant difference in DFT/T ratios between male and female children.
6. There is a significant difference in dft/t ratios between Asian and Hispanic children
attending Griffin Elementary school.
7. There is a significant difference in DFT/T ratios between Asian and Hispanic children
attending Griffin Elementary school.
Null Hypotheses
1. There is no significant correlation and linear regression between dft/t and DFT/T.
2. There is no significant difference in the number of dental caries on primary teeth and
history of caries on primary teeth (measured by the dft/t ratio) between Griffin and
Rossmoor Elementary children.
7
3. There is no significant difference in number of dental caries on permanent teeth and
history of caries on permanent teeth (measured by the DFT/T ratio) between Griffin and
Rossmoor Elementary children.
4. There is no significant difference in dft/t between male and female children.
5. There is no significant difference in DFT/T between male and female children.
6. There is no significant difference in dft/t between Asian and Hispanic children
attending Griffin Elementary school.
7. There is no significant difference in DFT/T between Asian and Hispanic children
attending Griffin Elementary school.
8
Chapter 4: Materials and Methods
Student and School Characteristics
Dental caries patterns in primary and permanent dentition were assessed for
children 7 to 10 years old in this prospective study. Human subjects were from two
schools in the Southern California area (Griffin and Rossmoor Elementary). Children
from Griffin Elementary were examined from 2003 to 2006. Children from Rossmoor
Elementary were examined in 2005 and 2006. Griffin Elementary is a public school that
is located in Los Angeles County and is a part of the Los Angeles Unified School
District. Rossmoor Elementary is a public school that is located in Orange County and is
a part of the Los Alamitos Unified School District.
The study consisted of 268 children from Griffin Elementary and 108 children
from Rossmoor Elementary.
For Griffin Elementary, 43% of the children in this study were male and 57% of
the children in this study were female. In Griffin Elementary, 34% of the children were
Asian and 66% were Hispanic. According to the School’s Fiscal Services Division, there
was an 83.6% average percent enrollment in the Free Reduced Price Meals program at
Griffin Elementary during 2003 to 2006.
For Rossmoor elementary, 61% of the children in this study were male and 39%
of the children in this study were female. Of the 108 Rossmoor Elementary School
children, 3% were Asian/Pacific Islander, 6% were Hispanic, 67% were White, 1% was
Black, and 23% were of multiple races or did not respond. According to the school’s
Fiscal Services Division, there was an 8.5% average percent enrollment in the Free
9
Reduced Price Meals program at Rossmoor Elementary in 2005 to 2006. A summary of
this data is presented in Figure 1.
Figure 1: Breakdown of Students at Griffin and Rossmoor Elementary
Griffin Elementary
● 268 Total Children
● 43% Male, 57% Female
● 34% Asian, 66% Hispanic
● 83.6% Average Percent Enrollment in Free Reduced Price Meals Program
Rossmoor Elementary
● 108 Total Children
● 61% Male, 39% Female
● 3% Asian/Pacific Islander, 6% Hispanic, 67% White (Non-Hispanic), 1% Black
(African-American), and 23% Multiple Races or Did Not Respond
● 8.5% Average Percent Enrollment in Free Reduced Price Meals Program
Institutional Review Board
A medical questionnaire and consent was provided to the child’s parent; the study
participants assented on site prior to inclusion, all in accordance with and approved by
the University of Southern California’s Institutional Review Board (HS-025033).
Participation in this study was on a voluntary basis.
Measurement of Dental Caries
Dental examination for caries was done by a single investigator: Dr. Joyce
Galligan, RN, DDS. Teeth were also examined
for crowns, sealants, and restorations.
Furthermore, teeth that were unerupted or missing due orthodontic work were noted. The
examination did not involve taking and looking at dental x-rays. Dental evaluations were
completed using a mouth mirror and an explorer.
10
Explanation of dft/t and DFT/T Ratios
DFT/T represents the ratio of decayed and filled permanent teeth over the total
number of permanent teeth. On the other hand, dft/t represents the ratio of decayed and
filled primary teeth over the total number of primary teeth remaining. A ratio was used
because of the changing patterns in mixed dentition. In our study, any tooth that was
filled was assumed to have a history of decay.
Data Analysis
The statistical analysis was performed using Microsoft Excel 2003 (Redmond,
WA) and SigmaStat 3.5 (Point Richmond, CA). Presence or history of caries on the
permanent teeth (defined by the DFT/T ratio) was the dependent variable. Presence or
history of caries on the primary teeth (defined by the dft/t ratio) was the independent
variable. The data was categorized by age and school to detect dental caries patterns of
each group. Linear regression analyses were used to determine whether there was a
significant correlation between dft/t and DFT/T. All children with one or more sealants
on their permanent teeth were not included in the linear regression analysis. The levels of
significance was p < .05 and in addition p ≥ .05 was not considered significant. Each
child’s dft/t was plotted on the X-axis and DFT/T was plotted on the Y-axis. A best fit
line was drawn to determine the relationship between the independent variable (dft/t) and
the dependent variable (DFT/T). Both the Pearson product-moment correlation
coefficient (r) and coefficient of determination (r
2
) were calculated.
11
An unpaired t-tests was used to see if there was a significant difference between
the schools (Griffin and Rossmoor), between the sexes (male and female), and between
the two ethnicities (Asian and Hispanic). Kolmogorov-Smirnov test was used to
determine if the population was normally distributed and the Levene equal variance test
was used to test the equivalency of variances. If the data from a particular age group
failed the Kolmogorov-Smirnov normality test, the Mann-Whitney Rank Sum Test was
used. If the data from a particular age group passed the Kolmogorov-Smirnov normality
test but failed the equal variance test, the Mann-Whitney Rank Sum Test was also used to
see if there was a significant difference between the schools (Griffin and Rossmoor),
between the sexes (male and female), and between the two ethnicities (Hispanic and
Asian).
The Mann-Whitney Rank Sum test was used most of the time because most of the
data were not considered to be drawn from normally distributed populations with equal
variances. The Mann-Whitney Rank Sum Test is used to test for a difference between
two groups that is greater than what can be attributed to random sampling variation. The
null hypothesis is that the two samples were not drawn from populations from different
medians. The Rank Sum Test is a nonparametric procedure, which does not require
assuming normality or equal variance. It ranks all the observations from smallest to
largest without regard to which group each observation comes from. The ranks for each
group are summed and the rank sums compared. If there is no difference between the two
groups, the mean ranks should be approximately the same. If they differ by a large
amount, this study assumed that the low ranks tend to be in one group and the high ranks
are in the other, and concluded that the samples were drawn from different populations
12
(i.e. that there is a statistically significant difference). Since some age groups showed
both normality and equal variance, the data was analyzed with the more powerful
unpaired t-test instead.
13
Chapter 5: Results
Caries Correlation and Linear Regression Analysis
For Griffin Elementary children, there was a significant correlation (p < 0.05)
between dft/t and DFT/T for 8 year olds (p = 0.002, n = 68) and 9 year olds (p = 0.018, n
= 35), but there was not a significant correlation between dft/t and DFT/T for 7 year olds
(p = 0.493, n = 27) and 10 year olds (p = 0.182, n = 16). See Figure 2. Also, any children
with sealants on their permanent teeth were not included in this linear regression.
Figure 2: Linear Regression and Equation for Griffin Elementary Children
7 Year Olds From Griffin Elementary
r = 0.138
y = -0.1009x + 0.1984
r
2
= 0.019
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
dft/t
DFT/T
8 Year Olds From Griffin Elementary
r = 0.368
y = 0.2249x + 0.0727
r
2
= 0.1352
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
dft/t
DFT/T
14
(Figure 2, Continued)
9 Year Olds From Griffin Elementary
r = 0.397
y = 0.2052x + 0.0823
r
2
= 0.1579
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
dft/t
DFT/T
10 Year Olds From Griffin Elementary
r = 0.351
y = 0.1519x + 0.0609
r
2
= 0.1234
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
dft/t
DFT/T
For Rossmoor Elementary children there was a significant correlation (p < 0.05)
between dft/t and DFT/T for 7 year olds (p < 0.001, n = 20), 8 year olds (p < 0.001, n =
29), and 9 year olds (p < 0.001, n = 22), but there was not a significant correlation
between dft/t and DFT/T for 10 year olds (p = 0.591, n = 9). See Figure 3. Also, any
children with sealants on their permanent teeth were not included in this linear regression.
15
Figure 3: Linear Regression and Equation for Rossmoor Elementary Children
7 Year Olds From Rossmoor Elementary
r = 0.805
y = 0.5618x - 0.0253
r
2
= 0.6488
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
dft/t
DFT/T
8 Year Olds From Rossmoor Elementary
r = 0.613
y = 0.1566x - 0.0052
r
2
= 0.3752
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
dft/t
DFT/T
9 Year Olds From Rossmoor Elementary
r = 0.709
y = 0.3534x + 0.0136
r
2
= 0.502
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
dft/t
DFT/T
16
(Figure 3, Continued)
10 Year Olds From Rossmoor Elementary
r = 0.208
y = 0.0231x + 0.0048
r
2
= 0.0434
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
dft/t
DFT/T
Mann-Whitney Rank Sum Test of dft/t Scores Between Schools
To see if there was a significant difference in dft/t scores between Rossmoor and
Griffin Elementary children at a particular age, Mann-Whitney Rank Sum Test was used.
An unpaired t-test was not used because the data for dft/t scores did not pass both the
Kolmogorov-Smirnov normality test and Levene equal variance test.
For 7 year old Griffin and Rossmoor children, the difference in the median values
between the two groups is greater than would be expected by chance. In other words,
there was a statistically significant difference between Rossmoor dft/t scores and Griffin
dft/t scores (p < 0.001). See Table 1.
Table 1: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old Griffin and
Rossmoor dft/t Scores
Group N Median 25% 75%
Griffin dft/t 50 0.388 0.231 0.571
Rossmoor dft/t 24 0.0278 0.000 0.160
For 8 year old Griffin and Rossmoor children, the difference in the median values
between the two groups is greater than would be expected by chance. In other words,
17
there was a statistically significant difference between Rossmoor dft/t scores and Griffin
dft/t scores (p < 0.001). See Table 2.
Table 2: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old Griffin and
Rossmoor dft/t Scores
Group N Median 25% 75%
Griffin dft/t 105 0.500 0.195 0.587
Rossmoor dft/t 37 0.133 0.000 0.291
For 9 year old Griffin and Rossmoor children, the difference in the median values
between the two groups is greater than would be expected by chance. In other words,
there was a statistically significant difference between Rossmoor dft/t scores and Griffin
dft/t scores (p < 0.001). See Table 3.
Table 3: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old Griffin and
Rossmoor dft/t Scores
Group N Median 25% 75%
Griffin dft/t 81 0.417 0.122 0.644
Rossmoor dft/t 33 0.1000 0.000 0.288
For 10 year old Griffin and Rossmoor children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Rossmoor dft/t scores and Griffin dft/t scores
(p = 0.05). See Table 4.
Table 4: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old Griffin and
Rossmoor dft/t Scores
Group N Median 25% 75%
Griffin dft/t 32 0.400 0.0454 0.708
Rossmoor dft/t 14 0.113 0.000 0.333
18
Mann-Whitney Rank Sum Test of DFT/T Scores Between Schools
To see if there was a significant difference in DFT/T scores between Rossmoor
and Griffin Elementary children at a particular age, Mann-Whitney Rank Sum Test was
used. An unpaired t-test was not used because the data for DFT/T scores did not pass the
Kolmogorov-Smirnov normality test.
For 7 year old Griffin and Rossmoor children, the difference in the median values
between the two groups is greater than would be expected by chance. In other words,
there was a statistically significant difference between Rossmoor DFT/T scores and
Griffin DFT/T scores (p = 0.006). See Table 5.
Table 5: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old Griffin and
Rossmoor DFT/T Scores
Group N Median 25% 75%
Griffin DFT/T 50 0.0417 0.000 0.200
Rossmoor DFT/T 24 0.000 0.000 0.000
For 8 year old Griffin and Rossmoor children, the difference in the median values
between the two groups is greater than would be expected by chance. In other words,
there was a statistically significant difference between Rossmoor DFT/T scores and
Griffin DFT/T scores (p < 0.001). See Table 6.
Table 6: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old Griffin and
Rossmoor DFT/T Scores
Group N Median 25% 75%
Griffin DFT/T 105 0.1000 0.000 0.206
Rossmoor DFT/T 37 0.000 0.000 0.000
For 9 year old Griffin and Rossmoor children, the difference in the median values
between the two groups is greater than would be expected by chance. In other words,
19
there was a statistically significant difference between Rossmoor DFT/T scores and
Griffin DFT/T scores (p = 0.002). See Table 7.
Table 7: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old Griffin and
Rossmoor DFT/T Scores
Group N Median 25% 75%
Griffin DFT/T 81 0.0833 0.000 0.183
Rossmoor DFT/T 33 0.000 0.000 0.0744
For 10 year old Griffin and Rossmoor children, the difference in the median
values between the two groups is greater than would be expected by chance. In other
words, there was a statistically significant difference between Rossmoor DFT/T scores
and Griffin DFT/T scores (p < 0.001). See Table 8.
Table 8: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old Griffin and
Rossmoor DFT/T Scores
Group N Median 25% 75%
Griffin DFT/T 32 0.0556 0.000 0.148
Rossmoor DFT/T 14 0.000 0.000 0.000
Unpaired t-test and Mann-Whitney Rank Sum Test of dft/t Scores Between Males and
Females at Rossmoor Elementary
To see if there was a significant difference in dft/t scores between Rossmoor
Elementary males and females at a particular age, Mann-Whitney Rank Sum Test was
used for 7 year olds, 8 year olds, and 9 year olds. An unpaired t-test was not used for 7, 8,
and 9 year olds because the dft/t data did not pass the Kolmogorov-Smirnov normality
test. An unpaired t-test was used, however, for 10 year old Rossmoor Elementary males
and female children because the 10 year old Rossmoor dft/t male and female data passed
both the Kolmogorov-Smirnov normality test and Levene equal variance test.
20
Hence, for 7 year old Rossmoor male and female children, the difference in the
median values between the two groups is not great enough to exclude the possibility that
the difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Rossmoor male and female dft/t scores (p =
0.757). See Table 9.
Table 9: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old Rossmoor Male
and Female dft/t Scores
Group N Median 25% 75%
Male dft/t 11 0.000 0.000 0.269
Female dft/t 13 0.0556 0.000 0.117
For 8 year old Rossmoor male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Rossmoor male and female dft/t scores (p =
0.507). See Table 10.
Table 10: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old Rossmoor Male
and Female dft/t Scores
Group N Median 25% 75%
Male dft/t 24 0.108 0.000 0.268
Female dft/t 13 0.167 0.000 0.427
For 9 year old Rossmoor male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Rossmoor male and female dft/t scores (p =
0.415). See Table 11.
21
Table 11: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old Rossmoor Male
and Female dft/t Scores
Group N Median 25% 75%
Male dft/t 23 0.167 0.000 0.318
Female dft/t 10 0.0500 0.000 0.167
For 10 year old Rossmoor male and female children, the difference in the mean
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Rossmoor male and female dft/t scores (p =
0.427). See Table 12.
Table 12: Data Used for Unpaired t-test on 10 Year Old Rossmoor Male and Female
dft/t Scores
Group Name N Mean Std. Dev Std. Error Mean
Male dft/t 8 0.148 0.189 0.0668
Female dft/t 6 0.244 0.251 0.102
Mann-Whitney Rank Sum Test of DFT/T Scores Between Males and Females at
Rossmoor Elementary
To see if there was a significant difference in DFT/T scores between males and
females at Rossmoor Elementary children at a particular age, Mann-Whitney Rank Sum
Test was used. An unpaired t-test was not used because the DFT/T data did not pass the
Kolmogorov-Smirnov normality test.
For 7 year old Rossmoor male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Rossmoor male and female DFT/T scores (p =
0.196). See Table 13.
22
Table 13: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old Rossmoor Male
and Female DFT/T Scores
Group N Median 25% 75%
Male DFT/T 11 0.000 0.000 0.0750
Female DFT/T 13 0.000 0.000 0.000
For 8 year old Rossmoor male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Rossmoor male and female DFT/T scores (p =
0.912). See Table 14.
Table 14: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old Rossmoor Male
and Female DFT/T Scores
Group N Median 25% 75%
Male DFT/T 24 0.000 0.000 0.000
Female DFT/T 13 0.000 0.000 0.0208
For 9 year old Rossmoor male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Rossmoor male and female DFT/T scores (p =
0.647). See Table 15.
Table 15: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old Rossmoor Male
and Female DFT/T Scores
Group N Median 25% 75%
Male DFT/T 23 0.000 0.000 0.0535
Female DFT/T 10 0.000 0.000 0.1000
For 10 year old Rossmoor male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
23
statistically significant difference between Rossmoor male and female DFT/T scores (p =
0.662). See Table 16.
Table 16: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old Rossmoor
Male and Female DFT/T Scores
Group N Median 25% 75%
Male DFT/T 8 0.000 0.000 0.000
Female DFT/T 6 0.000 0.000 0.000
Unpaired t-test and Mann-Whitney Rank Sum Test of dft/t Scores Between Males and
Females at Griffin Elementary
To see if there was a significant difference in dft/t scores between Griffin
Elementary males and females at a particular age, Mann-Whitney Rank Sum Test was
used for 8 year olds and 9 year olds. An unpaired t-test was not used for 8 and 9 year olds
because the dft/t data did not pass the Kolmogorov-Smirnov normality test. An unpaired
t-test was used, however, for 7 year old and 10 year old Griffin Elementary male and
female children because the data for 7 and 10 year olds passed both the Kolmogorov-
Smirnov normality test and Levene equal variance test.
Hence, for 7 year old Griffin male and female children, the difference in the mean
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin male and female dft/t scores (p =
0.576). See Table 17.
Table 17: Data Used for Unpaired t-test on 7 Year Old Griffin Male and Female dft/t
Scores
Group Name N Mean Std. Dev Std. Error Mean
Male dft/t 26 0.423 0.230 0.0450
Female dft/t 24 0.383 0.273 0.0558
24
For 8 year old Griffin male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin male and female dft/t scores (p =
0.898). See Table 18.
Table 18: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old Griffin Male
and Female dft/t Scores
Group N Median 25% 75%
Male dft/t 45 0.500 0.282 0.600
Female dft/t 59 0.500 0.182 0.583
For 9 year old Griffin male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin male and female dft/t scores (p =
0.607). See Table 19.
Table 19: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old Griffin Male
and Female dft/t Scores
Group N Missing Median 25% 75%
Male dft/t 37 0 0.333 0.108 0.644
Female dft/t 44 0 0.417 0.146 0.646
For 10 year old Griffin male and female children, the difference in the mean
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin male and female dft/t scores (p =
0.302). See Table 20.
25
Table 20: Data Used for Unpaired t-test on 10 Year Old Griffin Male and Female dft/t
Scores
Group Name N Mean Std. Dev Std. Error Mean
Male dft/t 8 0.303 0.326 0.115
Female dft/t 24 0.457 0.368 0.0752
Mann-Whitney Rank Sum Test of DFT/T Scores Between Males and Females at
Griffin Elementary
To see if there was a significant difference in DFT/T scores between Griffin
Elementary males and females at a particular age, Mann-Whitney Rank Sum Test was
used. An unpaired t-test was not used because the DFT/T data did not pass the
Kolmogorov-Smirnov normality test.
For 7 year old Griffin male and female children, the difference in the median
values between the two groups is greater than would be expected by chance. In other
words, there was a statistically significant difference between Griffin male and female
DFT/T scores (p = 0.021). See Table 21.
Table 21: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old Griffin Male
and Female DFT/T Scores
Group N Median 25% 75%
Male DFT/T 26 0.000 0.000 0.111
Female DFT/T 24 0.118 0.000 0.275
For 8 year old Griffin male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin male and female DFT/T scores (p =
0.814). See Table 22.
26
Table 22: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old Griffin Male
and Female DFT/T Scores
Group N Median 25% 75%
Male DFT/T 45 0.1000 0.000 0.250
Female DFT/T 59 0.1000 0.000 0.200
For 9 year old Griffin male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin male and female DFT/T scores (p =
0.152). See Table 23.
Table 23: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old Griffin Male
and Female DFT/T Scores
Group N Median 25% 75%
Male DFT/T 37 0.000 0.000 0.170
Female DFT/T 44 0.108 0.0263 0.201
For 10 year old Griffin male and female children, the difference in the median
values between the two groups is not great enough to exclude the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin male and female DFT/T scores (p =
0.187). See Table 24.
Table 24: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old Griffin Male
and Female DFT/T Scores
Group N Median 25% 75%
Male DFT/T 8 0.000 0.000 0.192
Female DFT/T 24 0.0711 0.0228 0.148
27
Unpaired t-test and Mann-Whitney Rank Sum Test of dft/t Scores Between Asian and
Hispanic Children at Griffin Elementary
To see if there was a significant difference in dft/t scores between Griffin
Elementary Asian and Hispanic children at a particular age, Mann-Whitney Rank Sum
Test was used for 8 year olds and 10 year olds. An unpaired t-test was not used for 8 and
10 year olds because the dft/t data did not pass the Kolmogorov-Smirnov normality test.
An unpaired t-test was used, however, for 7 year old and 9 year old Griffin Elementary
Asian and Hispanic children because the data for 7 and 9 year olds passed both the
Kolmogorov-Smirnov normality test and Levene equal variance test.
Hence, for 7 year old Griffin Asian and Hispanic children, the difference in the
mean values between the two groups is greater than would be expected by chance. In
other words, there was a statistically significant difference between Griffin Asian and
Hispanic dft/t scores (p = 0.037). See Table 25.
Table 25: Data Used for Unpaired t-test on 7 Year Old Griffin Asian and Hispanic dft/t
Scores
Group N Mean Std Dev Std. Error Mean
Asian dft/t 19 0.497 0.239 0.0548
Hispanic dft/t 31 0.346 0.242 0.0435
For 8 year old Griffin Asian and Hispanic children, the difference in the median
values between the two groups is greater than would be expected by chance. In other
words, there was a statistically significant difference between Griffin Asian and Hispanic
dft/t scores (p = 0.047). See Table 26.
Table 26: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old Griffin Asian
and Hispanic dft/t Scores
Group N Median 25% 75%
Asian dft/t 41 0.500 0.406 0.600
Hispanic dft/t 64 0.455 0.167 0.569
28
For 9 year old Griffin Asian and Hispanic children, the difference in the mean
values between the two groups is not great enough to reject the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin Asian and Hispanic dft/t scores (p =
0.346). See Table 27.
Table 27: Data Used for Unpaired t-test on 9 Year Old Griffin Asian and Hispanic dft/t
Scores
Group N Mean Std Dev Std. Error Mean
Asian dft/t 23 0.445 0.308 0.0642
Hispanic dft/t 57 0.376 0.289 0.0383
For 10 year old Griffin Asian and Hispanic children, the difference in the median
values between the two groups is not great enough to reject the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin Asian and Hispanic dft/t scores (p =
0.644). See Table 28.
Table 28: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old Griffin Asian
and Hispanic dft/t Scores
Group N Missing Median 25% 75%
Asian dft/t 8 0 0.367 0.167 0.400
Hispanic dft/t 24 0 0.473 0.0455 0.775
Mann-Whitney Rank Sum Test of DFT/T Scores Between Asian and Hispanic
Children at Griffin Elementary
To see if there was a significant difference in DFT/T scores between Griffin
Elementary Asian and Hispanic children at a particular age, Mann-Whitney Rank Sum
29
Test was used for. An unpaired t-test was not used for 8 and 10 year olds because the
DFT/T data did not pass the Kolmogorov-Smirnov normality test.
For 7 year old Griffin Asian and Hispanic children, the difference in the median
values between the two groups is not great enough to reject the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin Asian and Hispanic DFT/T scores (p =
0.631). See Table 29.
Table 29: Data Used for Mann-Whitney Rank Sum Test on 7 Year Old Griffin Asian
and Hispanic DFT/T Scores
Group N Median 25% 75%
Asian DFT/T 19 0.1000 0.000 0.192
Hispanic DFT/T 31 0.000 0.000 0.200
For 8 year old Griffin Asian and Hispanic children, the difference in the median
values between the two groups is not great enough to reject the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin Asian and Hispanic DFT/T scores (p =
0.265). See Table 30.
Table 30: Data Used for Mann-Whitney Rank Sum Test on 8 Year Old Griffin Asian
and Hispanic DFT/T Scores
Group N Median 25% 75%
Asian DFT/T 41 0.143 0.000 0.236
Hispanic DFT/T 64 0.0955 0.000 0.191
For 9 year old Griffin Asian and Hispanic children, the difference in the median
values between the two groups is not great enough to reject the possibility that the
difference is due to random sampling variability. In other words, there was not a
30
statistically significant difference between Griffin Asian and Hispanic DFT/T scores (p =
0.348). See Table 31.
Table 31: Data Used for Mann-Whitney Rank Sum Test on 9 Year Old Griffin Asian
and Hispanic DFT/T Scores
Group N Median 25% 75%
Asian DFT/T 23 0.1000 0.0131 0.241
Hispanic DFT/T 57 0.0769 0.000 0.170
For 10 year old Griffin Asian and Hispanic children, the difference in the median
values between the two groups is not great enough to reject the possibility that the
difference is due to random sampling variability. In other words, there was not a
statistically significant difference between Griffin Asian and Hispanic DFT/T scores (p =
0.876). See Table 32.
Table 32: Data Used for Mann-Whitney Rank Sum Test on 10 Year Old Griffin Asian
and Hispanic DFT/T Scores
Group N Median 25% 75%
Asian DFT/T 8 0.0815 0.000 0.160
Hispanic DFT/T 24 0.0556 0.000 0.148
Average dft/t and DFT/T Ratios for All Griffin and Rossmoor Elementary Children
The average dft/t ratio for all Griffin Elementary children (7-10 year olds) was
0.4072. The average DFT/T ratio for all Griffin Elementary children (7-10 year olds) was
0.1226. The total number of children computed for these averages was 268.
The average dft/t ratio for all Rossmoor Elementary children (7-10 year olds) was
0.1665. The average DFT/T ratio for all Rossmoor Elementary children (7-10 year olds)
was 0.0312. The total number of children computed for these averages was 108.
Hence, Griffin Elementary children had higher dft/t and DFT/T averages than
Rossmoor Elementary children. See Figure 4.
31
Figure 4: Bar Charts of Average dft/t and DFT/T Ratios for All Griffin and Rossmoor
Elementary Children
Average dft/t and DFT/T for Griffin 7-10 Year Old Children
0
0.1
0.2
0.3
0.4
0.5
dft/t DFT/T
Average Ratio
Average dft/t and DFT/T for Rossmoor 7-10 Year Old Children
0
0.1
0.2
0.3
0.4
0.5
dft/t DFT/T
Average Ratio
32
Chapter 6: Assumptions
There were two assumptions made in our study. First, the detection of caries and
the detection of dental restorations (filled teeth) were accurate. Second, children from
Griffin and Rossmoor Elementary schools combined were representative of the child
population elsewhere in the United States.
33
Chapter 7: Limitations
There were several potential limitations to this study. First, although there was no
selection bias involved because the children participated in this study on a voluntary
basis, it is possible that this patient population does not represent the population at large.
Second, the detection of caries and the detection of dental restorations (filled teeth) were
subjected to human error which includes possibly not detecting dental caries when one is
present. Last, our study did not analyze the ethnicity differences in Rossmoor Elementary
school children because when the different ethnicities were grouped according to ages,
there would often be only one student that was of one ethnicity. For example, there would
only be one African-American child being compared to many Hispanic and White
children. Therefore, this was an unfair comparison. Furthermore, with Rossmoor
Elementary children, there were many students that were of mixed races or did not
respond. This made it hard to analyze the racial differences in Rossmoor Elementary
school children.
34
Chapter 8: Discussion
For Griffin Elementary children, there was a significant correlation (p < 0.05)
between dft/t and DFT/T for 8 year olds and 9 year olds, but there was not a significant
correlation for 7 year olds and 10 year olds. For Rossmoor Elementary children there was
a significant correlation (p < 0.05) between dft/t and DFT/T for 7 year olds, 8 year olds,
and 9 year olds, but there was not a significant correlation for 10 year olds. In both cases,
10 year old children did not show significant correlation. The time span from 5 to
10 years of age covers a period where teeth of both dentitions coexist, sharing the
exposures related to caries occurrence (Skeie et al., 2001). At 10 years of age, most
children lose most of their primary dentition. This may be the reason why the significant
correlation goes away by age 10.
There was a statistically significant difference in schools for all dft/t and DFT/T
ratios except for 10 year old children’s dft/t scores. However, the p value for the
difference between 10 year old Griffin and Rossmoor dft/t score was 0.05, which is
extremely close to being significant. The fact that practically all Griffin and Rossmoor
dft/t and DFT/T ratios were significantly different reflects on the large difference in
averages of dft/t and DFT/T ratios between each school. The dft/t and DFT/T averages
were much greater at Griffin Elementary than at Rossmoor Elementary (See Figure 4). A
major reason why there was a difference between schools may be due to the economic
factor. This study did not measure the child’s economic status directly. However, a
measure of the economic status of the children at each school is what percentage of
children was enrolled for the Free and Reduced Price Meals Program (FRPM). FRPM is
a federally assisted meal program operating in public and nonprofit private schools and
35
residential child care institutions. The state of California also provides additional money
for this program. This program is intended to provide a nutritious meal to every low-
income student (O’Connell, 2008). To be eligible for FRPM, a family needs to make
130% or less of the federal income poverty level amount to qualify for free meals and
185% or less of the federal income poverty level amount to qualify for reduced priced
meals (United States Department of Agriculture, 2009). Hence, the higher the percentage
that students are enrolled in FRPM, the lower the children’s economic status at each
school. Griffin Elementary students had a much higher percentage enrollment in FRPM
(83.6%) than Rossmoor Elementary students (8.5%). Hence as was the case in the study
by Li and Wang in 2002, lower economic status children had more decay on their
primary teeth than higher economic status children. Also, like other studies (Kaste et al.,
1996; Beltrán-Aguilar et al., 2005) the lower economic children (Griffin Elementary
students) also had more decay on their permanent teeth than higher economic status
children (Rossmoor Elementary students).
There are many questionnaires that assess caries risk and asking the child’s parent
whether their child is enrolled in FRPM program could be a valid caries risk indicator
question. One such program that has a questionnaire for the patients is called the “Caries
management by risk assessment” (CAMBRA) which represents an
evidence-based
approach to preventing, reversing, and treating
dental caries (Young et al., 2007). Among
the questions that are asked in CAMBRA include whether there are: restorations in the
last three years, white spots on smooth surfaces, radiographic approximal enamel lesions
(not in dentin), and visible cavities or radiographic penetration of the dentin
(Featherstone et al., 2007). Unfortunately, there is not a question about the economic
36
status of the child or about enrollment of the FRPM program. Such a question could
indicate whether the child’s parents have the financial means to get dental care and
additional preventative dental care. If the parent does not have the financial means, the
dental professional could direct the parent to free dental clinics or federal and state
sponsored programs where dental care could be provided for low-income families and
children.
Another caries risk questionnaire was produced by the American Academy of
Pediatric Dentistry (AAPD). AAPD adopted
the Caries-Risk Assessment Tool (CAT) for
determining caries
risk in children. In CAT there is one question about whether the child
has decay (AAPD, 2002). Factoring in dft/t and DFT/T ratios into CAT could make this
caries risk assessment more powerful.
In regards to the difference in dft/t and DFT/T between male and female children,
there was only a significant difference in DFT/T scores between male and female 7 year
olds at Griffin Elementary. Seven year old female Griffin children had a higher average
DFT/T score (0.158) than male students (0.065) and the female students had a higher
median (0.118) than male students (0.0). This finding is in agreement that caries
experience in permanent teeth was higher among females than males in the 6 to 19 year
old age group (Beltrán-Aguilar et al., 2005). However there was not a significant
difference between males and females for any other age category. This may mean that the
difference between male and female dental caries pattern in permanent teeth only
consistently show up later in life because our study only analyzed caries patterns of 7 to
10 year old children.
37
In regards to the difference in dft/t and DFT/T between Asian and Hispanic
children, there were only significant differences in dft/t scores in 7 year old and 8 year
old Griffin children. According to the study by Beltrán-Aguilar conducted in 2005,
Mexican-Americans or Hispanics had the highest caries experience in primary teeth as
compared to other ethnicities. In our study, for 7 year old Griffin children (where a
significant difference was found between Asian and Hispanic children), Asian children
had higher dft/t averages (0.497) than Hispanic children (0.346). Also, in 8 year old
Griffin children (where a significant difference was found between Asian and Hispanic
children), Asian children had higher dft/t averages (0.481) than Hispanic children
(0.378). This is contrary to the findings in Beltrán-Aguilar’s study conducted in 2005.
Hence, more research is needed analyzing the dental caries pattern of Asian children as
compared to Hispanic children.
One strength of the study was the ability to look at both the primary and
permanent dentition at the same time. However, the main limitation was that the study
could not include dental caries data of all the permanent teeth. Hence, the strength of the
study was also its limitation. Because the study examined school children between the
ages of 7 and 10, most permanent teeth (i.e. premolars, second molars, and canines) do
not fully erupt by the age of 10. Therefore, gathering dental caries data for these Griffin
and Rossmoor Elementary children when all of their permanent teeth erupt would provide
a greater understanding of the statistical relationship between primary and permanent
caries. Also, this study did not look at whether the two different schools had fluoride in
their water supply or if the individual schools had a fluoride mouth rinse program.
38
Finally, more sensitive caries diagnostic and detecting techniques are needed for future
studies.
39
Chapter 9: Conclusion
Overall, this study demonstrated a significant positive correlation between caries
in primary and permanent dentitions. Future caries development should be continued to
be based on overall risk estimation. In the overall risk estimation analysis, whether a
child is enrolled in the Free and Reduced Price Meals Program (FRPM) should be
included and dft/t and DFT/T ratios should also be included. If future studies continue to
show that those schools with a high enrollment of FRPM have higher dft/t and DFT/T
ratios, more public oral health funds should be concentrated at schools with high FRPM
enrollment. In mixed dentition children, assessment of caries status in primary teeth is an
important prognostic tool to predict future caries. Hence, a high dft/t ratio of a child could
indicate that preventative measures need to be taken quickly on the remaining primary
teeth and on erupting permanent teeth, in anticipation of future caries.
40
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Interorganizational Collaboration in Dentistry: The CAMBRA Coalition Model. J Dent
Educ 71(5):595-600.
Abstract (if available)
Abstract
Introduction: High caries prevalence in children is a major oral health issue. Few studies about dental caries have been conducted on children with mixed dentitions (presence of both primary and permanent teeth). Specific information is needed validating the correlation between caries in primary and permanent teeth in the same child. Methods: Dental caries patterns were assessed for children 7 to 10 years old from two different elementary schools. Linear regression analysis was used to determine whether the presence of caries in the primary teeth significantly correlated with caries in the permanent teeth. Results: The study found significant correlations between caries in primary and permanent dentitions (p < 0.05). The highest correlation was found among 7 year old children at one elementary school (r=.805, p < 0.001). Conclusion: Decay on primary teeth should be a risk indicator for caries in permanent teeth.
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University of Southern California Dissertations and Theses
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Asset Metadata
Creator
Kim, Howard Hyung-won
(author)
Core Title
The correlation between dental caries in primary and permanent teeth in children at two different elementary schools
School
School of Dentistry
Degree
Master of Science
Degree Program
Craniofacial Biology
Publication Date
04/06/2009
Defense Date
03/19/2009
Publisher
University of Southern California
(original),
University of Southern California. Libraries
(digital)
Tag
caries,caries prediction,dental caries,mixed dentition,OAI-PMH Harvest,primary and permanent teeth,risk indicator
Language
English
Contributor
Electronically uploaded by the author
(provenance)
Advisor
Denny, Paul C. (
committee chair
), Paine, Michael L. (
committee member
), Sameshima, Glenn T. (
committee member
)
Creator Email
hkim825@gmail.com,howardhk@usc.edu
Permanent Link (DOI)
https://doi.org/10.25549/usctheses-m2054
Unique identifier
UC1306143
Identifier
etd-Kim-2779 (filename),usctheses-m40 (legacy collection record id),usctheses-c127-205660 (legacy record id),usctheses-m2054 (legacy record id)
Legacy Identifier
etd-Kim-2779.pdf
Dmrecord
205660
Document Type
Thesis
Rights
Kim, Howard Hyung-won
Type
texts
Source
University of Southern California
(contributing entity),
University of Southern California Dissertations and Theses
(collection)
Repository Name
Libraries, University of Southern California
Repository Location
Los Angeles, California
Repository Email
cisadmin@lib.usc.edu
Tags
caries
caries prediction
dental caries
mixed dentition
primary and permanent teeth
risk indicator