- Email: [email protected]
TRENDS IN UNTREATED CARIES IN PERMANENT TEETH OF CHILDREN 6 TO 18 YEARS OLD
A
D
J
A
✷
IO N
A
T
T
CON I
N U
IN G
ED
U
ARTICLE 4
TRENDS IN UNTREATED CARIES IN PERMANENT TEETH OF CHILDREN 6 TO 18 YEARS OLD L. JACKSON BROWN, D.D.S., PH.D.; THOMAS P. WALL, M.A., M.B.A.; VICKIE LAZAR, M.A., M.S.
A
B
S
T
R
A
C
T
Background. This article is the first in a series of three that focus on recent changes in the caries status of children and adolescents in the United States. Methods. This study is based on analyses of data regarding untreated carious permanent teeth among children 6 to 18 years of age from the first and third National Health and Nutrition Examination Surveys, or NHANES I and NHANES III. The NHANES is periodically conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention. Results. Overall, the number of carious permanent teeth among children 6 to 18 years old decreased from 1.43, as measured in NHANES I, to
First in a three-part series
The oral health of U.S. children has improved
since the early 1970s. In this article—the first of three analyzing this improvement—we report changes in untreated caries in the permanent teeth of children aged 6 to 18 years. A major focus of this study is how children from low-income households have fared relative to other segments of the population. A second article will focus on untreated caries in primary teeth, and a third will consider the total experience of caries (both treated and untreated) among children and adolescents.
METHODS
Data reported and discussed here are based on
0.33, as measured in NHANES III. The number of carious permanent teeth in children 6 to 18 years old also decreased across four demographic variables: age, sex, race and poverty level. Conclusions. The number of untreated carious permanent teeth among children has declined dramatically. Since the 1970s, the absolute difference in untreated caries between disadvantaged children and the rest of the child population has narrowed substantially. Practice Implications. The reduction in untreated caries, the major oral disease among children, has been dramatic in all subgroups of children. This may reinforce the already apparent shift from restorative to preventive dental services.
analyses of data from the first and third National Health and Nutrition Examination Surveys, or NHANES I1,2 and NHANES III.3 The NHANES is a periodic survey conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention. A major purpose of this survey is to measure and monitor indicators of the nutrition and health status of the U.S. civilian, noninstitutionalized population. Each survey is based on a complex sample design consisting of a multistage, stratified probability sample of clusters of people in geographic areas. Data for the NHANESs are collected from participants through face-to-face interviews, physical and dental examinations, and laboratory tests. NHANES I was conducted with a nationwide probability sample of approximately 28,000 people,
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
✷
1637
C
TRENDS aged 1 to 74 years, from the civilian, noninstitutionalized population of the conterminous United States, excluding people living on American Indian reservations. The survey started in April 1971 and was completed in June 1974. NHANES III was conducted with a nationwide probability sample of 39,695 people, 2 months of age or older, from the civilian, noninstitutionalized population in the 50 states and the District of Columbia. Several groups of people were oversampled to ensure statistically reliable estimates: blacks, Mexican-Americans, people 2 months to 5 years of age and people 60 years of age and older. NHANES III was conducted from October 1988 through October 1994. Dental caries levels in permanent teeth were recorded using the DMFT/S index. This index, in aggregate, represents the sum of the following components: dD = decayed teeth or untreated caries; dM = missing teeth; dF = filled teeth; dT = permanent teeth; dS = surfaces of those teeth. For our study, we used toothand surface-level data to create DT and DS indexes of decay. We modified tooth and surface codes in NHANES I to make them more compatible with the dental coding scheme used in NHANES III.2 We used the SUDAAN statistical package (Version 7.11, Research Triangle Institute) to calculate standard errors and perform statistical tests because it can adjust for the correlation introduced by the complex sample design. Age for both NHANES I and 1638
NHANES III is age as reported at the time of the dental examination. In this article, the data for permanent dentition are divided into two groups: those for children 6 to 11 years old and those for children 12 to 18 years old. The first group represents the age of mixed dentition; the latter represents adolescents, the large majority of whom have permanent teeth only. Poverty level in both NHANES I and NHANES III is defined as the ratio of family income to the federal poverty line. Each year, the U.S.
Among children between the ages of 6 and 18 years, the number of untreated carious permanent teeth decreased from 1.43 as measured by NHANES I to 0.33 as measured by NHANES III. Bureau of the Census establishes the federal poverty line and adjusts it by family composition and age of the family reference person. For this article, we created the following poverty categories: dat or below poverty line; dincome ranging from greater than 100 percent to 200 percent of poverty line; dincome ranging from greater than 200 percent to 300 percent of poverty line; dincome greater than 300 percent of poverty line. Percentage of missing data on the family income variable was noticeably higher in NHANES III than in NHANES I. We compared the caries expe-
rience of children for whom data on the family income variable were missing with that of children for whom data on the family income variable were available to identify possible bias associated with missing income data in NHANES III. We detected no significant differences. We coded race-ethnicity information in NHANES III in a way to make it most consistent with race information in NHANES I and thus maintain consistency over time. MexicanAmericans were grouped with whites, and Hispanic blacks were grouped with blacks. We dropped the residual racial category of “other” owing to a relatively large sampling variation. RESULTS
Number of untreated carious teeth. Overall. Among children between the ages of 6 and 18 years, the number of untreated carious permanent teeth (the D component of the DMFT/S index) decreased from 1.43 as measured by NHANES I to 0.33 as measured by NHANES III. Similarly, the number of carious surfaces decreased from 2.34 to 0.49 among children 6 to 18 years of age. This represents a 76.9 percent decline in untreated carious teeth and a 79.1 percent decline in untreated carious surfaces among these children (Table). (Because data for carious permanent surfaces follow the same trends as data for carious permanent teeth, from this point forward we will discuss only the number of untreated carious teeth. Data on carious permanent surfaces can be found in the table.) By age. The number of untreated carious permanent
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
TRENDS
TABLE
NUMBER OF UNTREATED CARIOUS PERMANENT TEETH AND SURFACES, AMONG CHILDREN 6 TO 18 YEARS OLD, NHANES* I (1971-1974) AND NHANES III (1988-1994).† SUBJECT CHARACTERISTIC
PERMANENT SURFACES
PERMANENT TEETH NHANES I
Difference‡
NHANES III
NHANES I
NHANES III
Difference‡
2.34
0.49
-1.85
Overall 6-18 Years Old
1.43
-1.10
0.33
Age (Years) 6-11
0.74
0.14
-0.60
1.18
0.18
-1.00
12-18
1.99
0.49
-1.50
3.27
0.76
-2.51
Sex Male
1.40
0.30
-1.10
2.27
0.46
-1.81
Female
1.47
0.35
-1.12
2.41
0.52
-1.89
Race White
1.28
0.26
-1.02
1.97
0.37
-1.60
Black
2.40
0.50
-1.90
4.60
0.83
-3.77
Poverty Level At or Below
2.14
0.46
-1.68
3.85
0.65
-3.20
> 100-200 %
1.71
0.49
-1.22
2.84
0.79
-2.05
> 200-300 %
1.20
0.27
-0.93
1.78
0.38
-1.40
> 300 %
0.78
0.11
-0.67
1.15
0.15
-1.00
1.29
0.28
-1.01
2.03
0.42
-1.61
Above
Age by Poverty Level 6-11 Years Old At or below
1.06
0.22
-0.84
1.93
0.26
-1.67
Above
0.66
0.12
-0.54
0.99
0.15
-0.84
3.24
0.70
-2.54
5.81
1.05
-4.76
1.78
0.42
-1.36
2.84
0.66
-2.18
12-18 Years Old At or below Above
Race by Poverty Level White At or below
1.88
0.43
-1.45
3.01
0.56
-2.45
Above
1.19
0.22
-0.97
1.82
0.32
-1.50
At or below
2.57
0.51
-2.06
5.19
0.85
-4.34
Above
2.23
0.49
-1.74
4.03
0.82
-3.21
Black
* NHANES: National Health and Nutrition Examination Survey. † Source: NHANES I1,2 and NHANES III.3 ‡ Differences were statistically significant at P < .0001.
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
1639
TRENDS
2.50 NHANES I (1971-1974)
NUMBER OF TEETH
2.14
NHANES III (1988-1994) 2.00
1.71 1.50
1.20 1.00
0.78
0.50
0.46
0.49 0.27 0.11
0.00
At or Below the Poverty Level
>100% to 200% of the Poverty Level
>200% to 300% of the Poverty Level
Above 300% of the Poverty Level
POVERTY LEVEL
Figure 1. Average number of untreated carious permanent teeth among children 6 to 18 years old by poverty level (First National Health and Nutrition Examination Survey, or NHANES I, 1971-1974,1,2 and Third National Health and Nutrition Examination Survey, or NHANES III,198819943).
teeth among children between the ages of 6 and 11 years decreased from 0.74 as measured by NHANES I to 0.14 as measured by NHANES III (a decrease of 81.1 percent). Among 12- to 18-year-olds, the number of carious permanent teeth decreased by 1.50 teeth, or from 1.99 to 0.49, during the same time period (a decrease of 75.4 percent) (Table). By poverty level. As can be seen in the table, between NHANES I and NHANES III, the average number of untreated carious permanent teeth decreased among children at or below the poverty level and among children above the poverty level. In both NHANES’ measurement periods, children at or below the poverty level experienced a higher level of decay in permanent teeth than did children above the poverty level. The absolute level of decrease in the average number of carious permanent teeth among children at or below the poverty level (1.68 teeth) was greater than the level of 1640
decrease among children above the poverty level (1.01 teeth). The percentage reduction in both groups was comparable (78.5 percent for the former vs. 78.3 percent for the latter). Children at or below the poverty level had, on average, 2.14 carious permanent teeth as measured by NHANES I. This average decreased to 0.46 permanent teeth as measured by NHANES III, representing a 78.5 percent decline. Similarly, the number of carious permanent teeth among children above the poverty level decreased from 1.29 in NHANES I to 0.28 in NHANES III, a 78.3 percent decrease. As depicted in Figure 1, in the period of 1971 through 1974 (NHANES I), the average number of carious permanent teeth was above 0.50 teeth across all four poverty categories. In the period of 1988 through 1994 (NHANES III), however, the average number of carious permanent teeth was below 0.50 teeth across all four poverty categories. Using NHANES I data and
comparing children at or below the poverty level with children above the poverty level, we found that the difference in the average number of carious permanent teeth was 0.85 teeth: 2.14 for children at or below the poverty level and 1.29 for children above the poverty level. Comparing children at or below the poverty level with children above the poverty level using NHANES III data, we found that the difference in the average number of carious permanent teeth dropped to 0.18 teeth (Table). By race. In both NHANES’ measurement periods, black children experienced a higher level of decay in permanent teeth than white children did. Among white children, the number of carious permanent teeth decreased by 1.02 teeth, or from 1.28 as measured by NHANES I to 0.26 as measured by NHANES III (a decrease of 79.7 percent). Among black children, the number of carious permanent teeth decreased by 1.90 teeth, or from 2.40 to 0.50, during this same period (a decrease of 79.2 percent) (Table). Comparing the average number of carious permanent teeth among white and black children in NHANES I, the difference was 1.12 teeth: 1.28 for white children and 2.40 for black children. The same comparison in NHANES III shows that the difference in the average number of carious permanent teeth dropped to 0.24 teeth: 0.26 for white children and 0.50 for black children. By sex. Among male children 6 to 18 years of age, the number of carious permanent teeth decreased by 78.6 percent, or from 1.40 teeth in NHANES I to 0.30 teeth in NHANES III. Sim-
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
TRENDS
ilarly, among female children, the number of carious permanent teeth decreased 76.2 percent, or from 1.47 teeth to 0.35 teeth, during the same measurement period (Table). By age and poverty level. In NHANES I, the average number of carious permanent teeth among children 6 to 11 years old who were at or below the poverty level was 0.40 teeth greater than that of their counterparts above the poverty level. Specifically, those at or below the poverty level had an average of 1.06 carious permanent teeth and those above the poverty level had an average of 0.66 carious permanent teeth. In NHANES III, however, the difference between the number of carious permanent teeth among children 6 to 11 years old according to poverty level dropped to 0.10 teeth. Those at or below the poverty level had an average of 0.22 carious permanent teeth and those above the poverty level had an average of 0.12 carious permanent teeth (Table). The difference between the number of carious permanent teeth among children 12 to 18 years old according to poverty level was 1.46 teeth in NHANES I. Those at or below the poverty level had an average of 3.24 carious permanent teeth, and those above the poverty level had an average of 1.78 carious permanent teeth. In contrast, in NHANES III, the difference between the number of carious permanent teeth among children 12 to 18 years old according to poverty level dropped to 0.28 teeth. Those at or below the poverty level had an average of 0.70 carious permanent teeth, and those above the poverty level had an aver-
age of 0.42 carious permanent teeth (Table). By race and poverty level. The difference between the number of carious permanent teeth among white children according to poverty level was 0.69 teeth in NHANES I. Those at or below the poverty level had an average of 1.88 carious permanent teeth and those above the poverty level had an average of 1.19 carious permanent teeth. In NHANES III, however, the difference between the number of carious teeth among white children according to poverty level dropped to 0.21 teeth. Those at or below the
In NHANES III, the difference between the number of carious teeth among white and black children above the poverty level was 0.27 teeth. poverty level had an average of 0.43 carious permanent teeth and those above the poverty level had an average of 0.22 carious permanent teeth (Table). In NHANES I, the difference between the number of carious permanent teeth among black children according to poverty level was 0.34 teeth. Those at or below the poverty level had an average of 2.57 carious permanent teeth and those above the poverty level had an average of 2.23 carious permanent teeth. In contrast, in NHANES III, the difference between the number of carious teeth among black children according to poverty level dropped to 0.02 teeth. Those at or below the poverty level had an average of 0.51 car-
ious permanent teeth and those above the poverty level had an average of 0.49 carious permanent teeth (Table). Among white and black children at or below the poverty level, the difference between the number of carious permanent teeth was 0.69 teeth as measured by NHANES I. White children at or below the poverty level had an average of 1.88 carious permanent teeth and black children at or below the poverty level had an average of 2.57 carious permanent teeth. In NHANES III, however, the difference between the number of carious teeth among white and black children at or below the poverty level dropped to 0.08 teeth: 0.43 and 0.51 carious permanent teeth, respectively. Among white and black children above the poverty level, the difference between the number of carious permanent teeth was 1.04 teeth as measured by NHANES I. White children above the poverty level had an average of 1.19 carious permanent teeth; black children above the poverty level had an average of 2.23 carious permanent teeth. In contrast, in NHANES III, the difference between the number of carious teeth among white and black children above the poverty level dropped to 0.27 teeth: 0.22 and 0.49 carious permanent teeth, respectively. Children without untreated caries. Children 6 to 11 years old. As illustrated in Figure 2, among children 6 to 11 years old who were at or below the poverty level, the percentage who had no untreated carious permanent teeth increased from 56.9 percent in NHANES I to 86.4 percent in NHANES III—or 29.5 per-
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
1641
PERCENTAGE OF CHILDREN WITHOUT UNTREATED CARIOUS TEETH
TRENDS
100
93.1 90
At or Below Poverty
86.4
83.3
Above Poverty
80
69.9
70 60
66.7
56.9 48.7
50 40
29.4
30 20 10 0
NHANES I: 6-11 Years Old
NHANES III: 6-11Years Old
NHANES I: 12-18 Years Old
NHANES III: 12-18 Years Old
DATA SOURCE AND AGE GROUP
Figure 2. Percentage of children 6 to 18 years old without untreated carious permanent teeth (First National Health and Nutrition Examination Survey, or NHANES I, 1971-1974,1,2 and Third National Health and Nutrition Examination Survey, or NHANES III,1988-19943).
centage points. Among children 6 to 11 years old who were above the poverty level, the percentage without untreated caries increased from 69.9 percent in NHANES I to 93.1 percent in NHANES III—or 23.2 percentage points. In NHANES III, regardless of poverty level, more than 85 percent of children 6 to 11 years old did not have any untreated carious permanent teeth: 86.4 percent of those at or below the poverty level and 93.1 percent of those above the poverty level. Children 12 to 18 years old. Similarly, among children 12 to 18 years old who were at or below the poverty level, the percentage without any untreated carious permanent teeth increased from 29.4 percent in NHANES I to 66.7 percent in NHANES III—or 37.3 percentage points. Among children 12 to 18 years old who were above the poverty level, the percentage without any untreated carious permanent teeth 1642
increased from 48.7 percent in NHANES I to 83.3 percent in NHANES III—or 34.6 percentage points (Figure 2). Extent of untreated caries among children with untreated caries. The average number of untreated carious permanent teeth among children with untreated caries declined between NHANES I and NHANES III. The most apparent improvement was the reduction in percentage of untreated caries among children with large numbers of carious teeth. Figures 3 and 4 show that among 6- to 11-yearolds and 12- to 18-year-olds at or below the poverty level and above the poverty level, there has been a distinct shift from multiple carious permanent teeth in NHANES I to one carious permanent tooth in NHANES III. Children 6 to 11 years old. Figure 3 shows data for children 6 to 11 years old who had untreated caries. The per-
centage of these children at or below the poverty level who had one carious permanent tooth increased by 33.9 percentage points, from 25.2 percent in NHANES I to 59.1 percent in NHANES III. In contrast, the percentage of children 6 to 11 years old at or below the poverty level who had four or more carious permanent teeth decreased by 18.4 percentage points, from 21.5 percent in NHANES I to 3.1 percent in NHANES III. Figure 3 also shows that the percentage of children 6 to 11 years old above the poverty level who had one untreated carious permanent tooth increased by 27.9 percentage points, from 37.5 percent in NHANES I to 65.4 percent in NHANES III. In contrast, the percentage of children 6 to 11 years old above the poverty level who had four or more untreated carious permanent teeth decreased by 5.6 percentage points, from 17.5 percent in NHANES I to 11.9 percent in NHANES III. Children 12 to 18 years old. Figure 4 shows data for 12- to 18-year-old children with untreated caries. The percentage of these children at or below the poverty level who had one carious permanent tooth increased by 23.2 percentage points, or from 19.8 percent in NHANES I to 43.0 percent in NHANES III. In contrast, the percentage of children 12 to 18 years old at or below the poverty level who had five or more untreated carious permanent teeth decreased by 33.3 percentage points, from 41.5 percent in NHANES I to 8.2 percent in NHANES III. Figure 4 also shows that the percentage of children 12 to 18
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
years old above the poverty level who had one untreated carious permanent tooth increased by 19.5 percentage points, or from 29.2 percent in NHANES I to 48.7 percent in NHANES III. In contrast, the percentage of children 12 to 18 years old above the poverty level who had five or more untreated carious permanent teeth decreased by 11.6 percentage points, from 24.4 percent in NHANES I to 12.8 percent in NHANES III.
PERCENTAGE OF CHILDREN WITH UNTREATED CARIOUS TEETH
TRENDS
70
65.4
1 Decayed Tooth 2 Decayed Teeth
59.1
60
3 Decayed Teeth 4 Decayed Teeth 5+ Decayed Teeth
50
37.5
40
34.7 29.1
30
25.2 21.3
18.6
20
16.5
15.3 10
15.8 14.2
16.1 6.6
6.2
8.3 3.6
3.3
1.6 1.5 0
NHANES I: At or NHANES III: At or Below the Poverty Below the Poverty Level Level
DISCUSSION
NHANES I: At the Poverty Level
NHANES III: At the Poverty Level
DATA SOURCE AND POVERTY LEVEL
Figure 3. Children 6 to 11 years old: percentage with specific numbers of carious teeth among those with untreated carious permanent teeth (First National Health and Nutrition Examination Survey, or NHANES I, 1971-1974,1,2 and Third National Health and Nutrition Examination Survey, or NHANES III,1988-19943). PERCENTAGE OF CHILDREN WITH UNTREATED CARIOUS TEETH
Our findings document the dramatic decline in untreated caries among children in the United States over a relatively short period. Overall, the number of untreated carious permanent teeth among children 6 to 18 years old dropped by 76.9 percent between NHANES I and NHANES III. Percentage decreases of 70 percent or more were achieved in all categories of age, sex, poverty and race. Absolute levels dropped to 0.5 carious teeth per child or fewer in almost all categories examined. The categories with the highest levels of untreated carious teeth in NHANES I experienced the largest absolute drops from NHANES I to NHANES III. The absolute decrease was a reduction of just more than one untreated carious permanent tooth per child. In 1991, the midpoint of the NHANES III survey, there were approximately 45,605,0004 children in this age category. Untreated caries has been reduced by nearly 50 million teeth in this age group. Although oral health differences based on poverty and race still exist, absolute differences
60 1 Decayed Tooth 2 Decayed Teeth
48.7
3 Decayed Teeth
50
41.5
4 Decayed Teeth
43.0
5+ Decayed Teeth
40
31.0
29.2
30
24.4 19.8 20
24.5
17.8 17.7 14.115.1
12.9
12.8
10.9
9.4
8.9
8.2
10
4.9
5.1
0
NHANES I: At or Below the Poverty Level
NHANES III: At or Below the Poverty Level
NHANES I: At the Poverty Level
NHANES III: At the Poverty Level
DATA SOURCE AND POVERTY LEVEL
Figure 4. Children 12 to 18 years old: percentage with specific numbers of carious teeth among those with untreated carious permanent teeth (First National Health and Nutrition Examination Survey, or NHANES I,1971-1974,1,2 and Third National Health and Nutrition Examination Survey, or NHANES III,1988-19943).
between poverty and racial categories in NHANES III were much smaller than those of 20 years earlier in NHANES I. In both NHANES I and NHANES III, black children experienced rates of untreated caries twice as high as those of their white counterparts. However, the
absolute disparity between black and white children decreased from 1.12 teeth in NHANES I to 0.24 teeth in NHANES III. Children living in poverty during the NHANES III period still exhibited more untreated caries in their permanent den-
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
1643
NUMBER OF UNTREATED CARIOUS PERMANENT TEETH
TRENDS
2.50
2.14
■
At or Below the Poverty Level
■
●
Above 300% of the Poverty Level
2.00
1.50
1.00
0.78
● 0.46 0.50
■ 0.11
●
0.00
NHANES I (1971-1974)
NHANES III (1988-1994)
DATA SOURCE
Figure 5. Average number of untreated carious permanent teeth among children 6 to 18 years old who were at or below the poverty level compared with those who were above 300 percent of the poverty level (First National Health and Nutrition Examination Survey, or NHANES I, 19711974,1,2 and Third National Health and Nutrition Examination Survey, or NHANES III,1988-19943).
tition than did children living above the poverty level. Nevertheless, these children experienced dramatic improvement in the percentage of teeth without untreated caries, the average number of untreated carious permanent teeth and the extent of untreated caries among those with the condition. As illustrated in Figure 5, the difference in the average number of untreated carious teeth in children at or below the poverty level and the average in those 300 percent above the poverty level narrowed substantially between NHANES I and NHANES III. The difference in the average number of carious teeth between the low and high ends of the poverty spectrum was 1.36 teeth in NHANES I. This disparity decreased to 0.35 teeth in NHANES III. The NHANES III data are nearly a decade old, so if the trends observed in these data continue, the current disparity
1644
may become even smaller.
major impact on the practice of dentistry in the United States as these surveyed children Dr. Brown is associate executive grow older. director, American The declines Dental Association, in untreated Health Policy Resources Center, caries may 211 E. Chicago Ave., reinforce the Chicago, Ill. 60611. Address reprint already requests to Dr. apparent Brown. shift5 from restorative to preventive dental services. Nevertheless, a question remains as to whether these declines in untreated caries will continue. Trends in caries as well as other oral health conditions merit careful monitoring during this period of change in dental diseases. ■
CONCLUSION
It is evident from the analysis presented here that although the condition of carious permanent teeth among children still exists and represents an oral health problem, it has diminished dramatically in both prevalence and extent across time for all poverty and race categories examined. There is no doubt that over the twodecade interval between NHANES I (1971-1974) and NHANES III (1988-1994), there has been a significant abatement of the prevalence of untreated carious permanent teeth among children 6 to 18 years old. Data presented here show that all segments of America’s child population have benefited from improved oral health. This is extremely good news for the nation’s children. The changes examined in this series of articles will have a
Mr. Wall is manager, Statistical Research, American Dental Association, Health Policy Resources Center, Chicago. Ms. Lazar is manager, Health Policy Analysis, American Dental Association, Health Policy Resources Center, Chicago. 1. U.S. Department of Commerce. National Technical Information Service, Division of Health Examination Statistics. National Health and Nutrition Examination Survey (NHANES I) 1971-1974. Hyattsville, Md.: National Technical Information Service; 1979. Dental Data Tape Catalog 4,235. 2. Thearmontree A, Eklund SA. Comparison between NHANES I and NHANES III: comparable NHANES I tooth and surface data (abstract 2076). J Dent Res 1999;78(special issue):365. 3. U.S. Department of Health and Human Services, National Center for Health Statistics. Third National Health and Nutrition Examination Survey, 1988-1994, NHANES III Examination Data File (database on CDROM). Hyattsville, Md.: National Center for Health Statistics; 1996. Public Use Data File Documentation Number 76,200. 4. U.S. Bureau of the Census. Statistical abstract of the United States: 1993. 113th ed. Washington, D.C.: Government Printing Office; 1993:16. 5. Brown LJ, Lazar V. The economic state of dentistry: demand-side trends. JADA 1998;129:1685-91.
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
D
J
A
✷
IO N
A
T
T
CON I
N U
IN G
ED
U
ARTICLE 4
TRENDS IN UNTREATED CARIES IN PERMANENT TEETH OF CHILDREN 6 TO 18 YEARS OLD L. JACKSON BROWN, D.D.S., PH.D.; THOMAS P. WALL, M.A., M.B.A.; VICKIE LAZAR, M.A., M.S.
A
B
S
T
R
A
C
T
Background. This article is the first in a series of three that focus on recent changes in the caries status of children and adolescents in the United States. Methods. This study is based on analyses of data regarding untreated carious permanent teeth among children 6 to 18 years of age from the first and third National Health and Nutrition Examination Surveys, or NHANES I and NHANES III. The NHANES is periodically conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention. Results. Overall, the number of carious permanent teeth among children 6 to 18 years old decreased from 1.43, as measured in NHANES I, to
First in a three-part series
The oral health of U.S. children has improved
since the early 1970s. In this article—the first of three analyzing this improvement—we report changes in untreated caries in the permanent teeth of children aged 6 to 18 years. A major focus of this study is how children from low-income households have fared relative to other segments of the population. A second article will focus on untreated caries in primary teeth, and a third will consider the total experience of caries (both treated and untreated) among children and adolescents.
METHODS
Data reported and discussed here are based on
0.33, as measured in NHANES III. The number of carious permanent teeth in children 6 to 18 years old also decreased across four demographic variables: age, sex, race and poverty level. Conclusions. The number of untreated carious permanent teeth among children has declined dramatically. Since the 1970s, the absolute difference in untreated caries between disadvantaged children and the rest of the child population has narrowed substantially. Practice Implications. The reduction in untreated caries, the major oral disease among children, has been dramatic in all subgroups of children. This may reinforce the already apparent shift from restorative to preventive dental services.
analyses of data from the first and third National Health and Nutrition Examination Surveys, or NHANES I1,2 and NHANES III.3 The NHANES is a periodic survey conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention. A major purpose of this survey is to measure and monitor indicators of the nutrition and health status of the U.S. civilian, noninstitutionalized population. Each survey is based on a complex sample design consisting of a multistage, stratified probability sample of clusters of people in geographic areas. Data for the NHANESs are collected from participants through face-to-face interviews, physical and dental examinations, and laboratory tests. NHANES I was conducted with a nationwide probability sample of approximately 28,000 people,
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
✷
1637
C
TRENDS aged 1 to 74 years, from the civilian, noninstitutionalized population of the conterminous United States, excluding people living on American Indian reservations. The survey started in April 1971 and was completed in June 1974. NHANES III was conducted with a nationwide probability sample of 39,695 people, 2 months of age or older, from the civilian, noninstitutionalized population in the 50 states and the District of Columbia. Several groups of people were oversampled to ensure statistically reliable estimates: blacks, Mexican-Americans, people 2 months to 5 years of age and people 60 years of age and older. NHANES III was conducted from October 1988 through October 1994. Dental caries levels in permanent teeth were recorded using the DMFT/S index. This index, in aggregate, represents the sum of the following components: dD = decayed teeth or untreated caries; dM = missing teeth; dF = filled teeth; dT = permanent teeth; dS = surfaces of those teeth. For our study, we used toothand surface-level data to create DT and DS indexes of decay. We modified tooth and surface codes in NHANES I to make them more compatible with the dental coding scheme used in NHANES III.2 We used the SUDAAN statistical package (Version 7.11, Research Triangle Institute) to calculate standard errors and perform statistical tests because it can adjust for the correlation introduced by the complex sample design. Age for both NHANES I and 1638
NHANES III is age as reported at the time of the dental examination. In this article, the data for permanent dentition are divided into two groups: those for children 6 to 11 years old and those for children 12 to 18 years old. The first group represents the age of mixed dentition; the latter represents adolescents, the large majority of whom have permanent teeth only. Poverty level in both NHANES I and NHANES III is defined as the ratio of family income to the federal poverty line. Each year, the U.S.
Among children between the ages of 6 and 18 years, the number of untreated carious permanent teeth decreased from 1.43 as measured by NHANES I to 0.33 as measured by NHANES III. Bureau of the Census establishes the federal poverty line and adjusts it by family composition and age of the family reference person. For this article, we created the following poverty categories: dat or below poverty line; dincome ranging from greater than 100 percent to 200 percent of poverty line; dincome ranging from greater than 200 percent to 300 percent of poverty line; dincome greater than 300 percent of poverty line. Percentage of missing data on the family income variable was noticeably higher in NHANES III than in NHANES I. We compared the caries expe-
rience of children for whom data on the family income variable were missing with that of children for whom data on the family income variable were available to identify possible bias associated with missing income data in NHANES III. We detected no significant differences. We coded race-ethnicity information in NHANES III in a way to make it most consistent with race information in NHANES I and thus maintain consistency over time. MexicanAmericans were grouped with whites, and Hispanic blacks were grouped with blacks. We dropped the residual racial category of “other” owing to a relatively large sampling variation. RESULTS
Number of untreated carious teeth. Overall. Among children between the ages of 6 and 18 years, the number of untreated carious permanent teeth (the D component of the DMFT/S index) decreased from 1.43 as measured by NHANES I to 0.33 as measured by NHANES III. Similarly, the number of carious surfaces decreased from 2.34 to 0.49 among children 6 to 18 years of age. This represents a 76.9 percent decline in untreated carious teeth and a 79.1 percent decline in untreated carious surfaces among these children (Table). (Because data for carious permanent surfaces follow the same trends as data for carious permanent teeth, from this point forward we will discuss only the number of untreated carious teeth. Data on carious permanent surfaces can be found in the table.) By age. The number of untreated carious permanent
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
TRENDS
TABLE
NUMBER OF UNTREATED CARIOUS PERMANENT TEETH AND SURFACES, AMONG CHILDREN 6 TO 18 YEARS OLD, NHANES* I (1971-1974) AND NHANES III (1988-1994).† SUBJECT CHARACTERISTIC
PERMANENT SURFACES
PERMANENT TEETH NHANES I
Difference‡
NHANES III
NHANES I
NHANES III
Difference‡
2.34
0.49
-1.85
Overall 6-18 Years Old
1.43
-1.10
0.33
Age (Years) 6-11
0.74
0.14
-0.60
1.18
0.18
-1.00
12-18
1.99
0.49
-1.50
3.27
0.76
-2.51
Sex Male
1.40
0.30
-1.10
2.27
0.46
-1.81
Female
1.47
0.35
-1.12
2.41
0.52
-1.89
Race White
1.28
0.26
-1.02
1.97
0.37
-1.60
Black
2.40
0.50
-1.90
4.60
0.83
-3.77
Poverty Level At or Below
2.14
0.46
-1.68
3.85
0.65
-3.20
> 100-200 %
1.71
0.49
-1.22
2.84
0.79
-2.05
> 200-300 %
1.20
0.27
-0.93
1.78
0.38
-1.40
> 300 %
0.78
0.11
-0.67
1.15
0.15
-1.00
1.29
0.28
-1.01
2.03
0.42
-1.61
Above
Age by Poverty Level 6-11 Years Old At or below
1.06
0.22
-0.84
1.93
0.26
-1.67
Above
0.66
0.12
-0.54
0.99
0.15
-0.84
3.24
0.70
-2.54
5.81
1.05
-4.76
1.78
0.42
-1.36
2.84
0.66
-2.18
12-18 Years Old At or below Above
Race by Poverty Level White At or below
1.88
0.43
-1.45
3.01
0.56
-2.45
Above
1.19
0.22
-0.97
1.82
0.32
-1.50
At or below
2.57
0.51
-2.06
5.19
0.85
-4.34
Above
2.23
0.49
-1.74
4.03
0.82
-3.21
Black
* NHANES: National Health and Nutrition Examination Survey. † Source: NHANES I1,2 and NHANES III.3 ‡ Differences were statistically significant at P < .0001.
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
1639
TRENDS
2.50 NHANES I (1971-1974)
NUMBER OF TEETH
2.14
NHANES III (1988-1994) 2.00
1.71 1.50
1.20 1.00
0.78
0.50
0.46
0.49 0.27 0.11
0.00
At or Below the Poverty Level
>100% to 200% of the Poverty Level
>200% to 300% of the Poverty Level
Above 300% of the Poverty Level
POVERTY LEVEL
Figure 1. Average number of untreated carious permanent teeth among children 6 to 18 years old by poverty level (First National Health and Nutrition Examination Survey, or NHANES I, 1971-1974,1,2 and Third National Health and Nutrition Examination Survey, or NHANES III,198819943).
teeth among children between the ages of 6 and 11 years decreased from 0.74 as measured by NHANES I to 0.14 as measured by NHANES III (a decrease of 81.1 percent). Among 12- to 18-year-olds, the number of carious permanent teeth decreased by 1.50 teeth, or from 1.99 to 0.49, during the same time period (a decrease of 75.4 percent) (Table). By poverty level. As can be seen in the table, between NHANES I and NHANES III, the average number of untreated carious permanent teeth decreased among children at or below the poverty level and among children above the poverty level. In both NHANES’ measurement periods, children at or below the poverty level experienced a higher level of decay in permanent teeth than did children above the poverty level. The absolute level of decrease in the average number of carious permanent teeth among children at or below the poverty level (1.68 teeth) was greater than the level of 1640
decrease among children above the poverty level (1.01 teeth). The percentage reduction in both groups was comparable (78.5 percent for the former vs. 78.3 percent for the latter). Children at or below the poverty level had, on average, 2.14 carious permanent teeth as measured by NHANES I. This average decreased to 0.46 permanent teeth as measured by NHANES III, representing a 78.5 percent decline. Similarly, the number of carious permanent teeth among children above the poverty level decreased from 1.29 in NHANES I to 0.28 in NHANES III, a 78.3 percent decrease. As depicted in Figure 1, in the period of 1971 through 1974 (NHANES I), the average number of carious permanent teeth was above 0.50 teeth across all four poverty categories. In the period of 1988 through 1994 (NHANES III), however, the average number of carious permanent teeth was below 0.50 teeth across all four poverty categories. Using NHANES I data and
comparing children at or below the poverty level with children above the poverty level, we found that the difference in the average number of carious permanent teeth was 0.85 teeth: 2.14 for children at or below the poverty level and 1.29 for children above the poverty level. Comparing children at or below the poverty level with children above the poverty level using NHANES III data, we found that the difference in the average number of carious permanent teeth dropped to 0.18 teeth (Table). By race. In both NHANES’ measurement periods, black children experienced a higher level of decay in permanent teeth than white children did. Among white children, the number of carious permanent teeth decreased by 1.02 teeth, or from 1.28 as measured by NHANES I to 0.26 as measured by NHANES III (a decrease of 79.7 percent). Among black children, the number of carious permanent teeth decreased by 1.90 teeth, or from 2.40 to 0.50, during this same period (a decrease of 79.2 percent) (Table). Comparing the average number of carious permanent teeth among white and black children in NHANES I, the difference was 1.12 teeth: 1.28 for white children and 2.40 for black children. The same comparison in NHANES III shows that the difference in the average number of carious permanent teeth dropped to 0.24 teeth: 0.26 for white children and 0.50 for black children. By sex. Among male children 6 to 18 years of age, the number of carious permanent teeth decreased by 78.6 percent, or from 1.40 teeth in NHANES I to 0.30 teeth in NHANES III. Sim-
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
TRENDS
ilarly, among female children, the number of carious permanent teeth decreased 76.2 percent, or from 1.47 teeth to 0.35 teeth, during the same measurement period (Table). By age and poverty level. In NHANES I, the average number of carious permanent teeth among children 6 to 11 years old who were at or below the poverty level was 0.40 teeth greater than that of their counterparts above the poverty level. Specifically, those at or below the poverty level had an average of 1.06 carious permanent teeth and those above the poverty level had an average of 0.66 carious permanent teeth. In NHANES III, however, the difference between the number of carious permanent teeth among children 6 to 11 years old according to poverty level dropped to 0.10 teeth. Those at or below the poverty level had an average of 0.22 carious permanent teeth and those above the poverty level had an average of 0.12 carious permanent teeth (Table). The difference between the number of carious permanent teeth among children 12 to 18 years old according to poverty level was 1.46 teeth in NHANES I. Those at or below the poverty level had an average of 3.24 carious permanent teeth, and those above the poverty level had an average of 1.78 carious permanent teeth. In contrast, in NHANES III, the difference between the number of carious permanent teeth among children 12 to 18 years old according to poverty level dropped to 0.28 teeth. Those at or below the poverty level had an average of 0.70 carious permanent teeth, and those above the poverty level had an aver-
age of 0.42 carious permanent teeth (Table). By race and poverty level. The difference between the number of carious permanent teeth among white children according to poverty level was 0.69 teeth in NHANES I. Those at or below the poverty level had an average of 1.88 carious permanent teeth and those above the poverty level had an average of 1.19 carious permanent teeth. In NHANES III, however, the difference between the number of carious teeth among white children according to poverty level dropped to 0.21 teeth. Those at or below the
In NHANES III, the difference between the number of carious teeth among white and black children above the poverty level was 0.27 teeth. poverty level had an average of 0.43 carious permanent teeth and those above the poverty level had an average of 0.22 carious permanent teeth (Table). In NHANES I, the difference between the number of carious permanent teeth among black children according to poverty level was 0.34 teeth. Those at or below the poverty level had an average of 2.57 carious permanent teeth and those above the poverty level had an average of 2.23 carious permanent teeth. In contrast, in NHANES III, the difference between the number of carious teeth among black children according to poverty level dropped to 0.02 teeth. Those at or below the poverty level had an average of 0.51 car-
ious permanent teeth and those above the poverty level had an average of 0.49 carious permanent teeth (Table). Among white and black children at or below the poverty level, the difference between the number of carious permanent teeth was 0.69 teeth as measured by NHANES I. White children at or below the poverty level had an average of 1.88 carious permanent teeth and black children at or below the poverty level had an average of 2.57 carious permanent teeth. In NHANES III, however, the difference between the number of carious teeth among white and black children at or below the poverty level dropped to 0.08 teeth: 0.43 and 0.51 carious permanent teeth, respectively. Among white and black children above the poverty level, the difference between the number of carious permanent teeth was 1.04 teeth as measured by NHANES I. White children above the poverty level had an average of 1.19 carious permanent teeth; black children above the poverty level had an average of 2.23 carious permanent teeth. In contrast, in NHANES III, the difference between the number of carious teeth among white and black children above the poverty level dropped to 0.27 teeth: 0.22 and 0.49 carious permanent teeth, respectively. Children without untreated caries. Children 6 to 11 years old. As illustrated in Figure 2, among children 6 to 11 years old who were at or below the poverty level, the percentage who had no untreated carious permanent teeth increased from 56.9 percent in NHANES I to 86.4 percent in NHANES III—or 29.5 per-
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
1641
PERCENTAGE OF CHILDREN WITHOUT UNTREATED CARIOUS TEETH
TRENDS
100
93.1 90
At or Below Poverty
86.4
83.3
Above Poverty
80
69.9
70 60
66.7
56.9 48.7
50 40
29.4
30 20 10 0
NHANES I: 6-11 Years Old
NHANES III: 6-11Years Old
NHANES I: 12-18 Years Old
NHANES III: 12-18 Years Old
DATA SOURCE AND AGE GROUP
Figure 2. Percentage of children 6 to 18 years old without untreated carious permanent teeth (First National Health and Nutrition Examination Survey, or NHANES I, 1971-1974,1,2 and Third National Health and Nutrition Examination Survey, or NHANES III,1988-19943).
centage points. Among children 6 to 11 years old who were above the poverty level, the percentage without untreated caries increased from 69.9 percent in NHANES I to 93.1 percent in NHANES III—or 23.2 percentage points. In NHANES III, regardless of poverty level, more than 85 percent of children 6 to 11 years old did not have any untreated carious permanent teeth: 86.4 percent of those at or below the poverty level and 93.1 percent of those above the poverty level. Children 12 to 18 years old. Similarly, among children 12 to 18 years old who were at or below the poverty level, the percentage without any untreated carious permanent teeth increased from 29.4 percent in NHANES I to 66.7 percent in NHANES III—or 37.3 percentage points. Among children 12 to 18 years old who were above the poverty level, the percentage without any untreated carious permanent teeth 1642
increased from 48.7 percent in NHANES I to 83.3 percent in NHANES III—or 34.6 percentage points (Figure 2). Extent of untreated caries among children with untreated caries. The average number of untreated carious permanent teeth among children with untreated caries declined between NHANES I and NHANES III. The most apparent improvement was the reduction in percentage of untreated caries among children with large numbers of carious teeth. Figures 3 and 4 show that among 6- to 11-yearolds and 12- to 18-year-olds at or below the poverty level and above the poverty level, there has been a distinct shift from multiple carious permanent teeth in NHANES I to one carious permanent tooth in NHANES III. Children 6 to 11 years old. Figure 3 shows data for children 6 to 11 years old who had untreated caries. The per-
centage of these children at or below the poverty level who had one carious permanent tooth increased by 33.9 percentage points, from 25.2 percent in NHANES I to 59.1 percent in NHANES III. In contrast, the percentage of children 6 to 11 years old at or below the poverty level who had four or more carious permanent teeth decreased by 18.4 percentage points, from 21.5 percent in NHANES I to 3.1 percent in NHANES III. Figure 3 also shows that the percentage of children 6 to 11 years old above the poverty level who had one untreated carious permanent tooth increased by 27.9 percentage points, from 37.5 percent in NHANES I to 65.4 percent in NHANES III. In contrast, the percentage of children 6 to 11 years old above the poverty level who had four or more untreated carious permanent teeth decreased by 5.6 percentage points, from 17.5 percent in NHANES I to 11.9 percent in NHANES III. Children 12 to 18 years old. Figure 4 shows data for 12- to 18-year-old children with untreated caries. The percentage of these children at or below the poverty level who had one carious permanent tooth increased by 23.2 percentage points, or from 19.8 percent in NHANES I to 43.0 percent in NHANES III. In contrast, the percentage of children 12 to 18 years old at or below the poverty level who had five or more untreated carious permanent teeth decreased by 33.3 percentage points, from 41.5 percent in NHANES I to 8.2 percent in NHANES III. Figure 4 also shows that the percentage of children 12 to 18
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
years old above the poverty level who had one untreated carious permanent tooth increased by 19.5 percentage points, or from 29.2 percent in NHANES I to 48.7 percent in NHANES III. In contrast, the percentage of children 12 to 18 years old above the poverty level who had five or more untreated carious permanent teeth decreased by 11.6 percentage points, from 24.4 percent in NHANES I to 12.8 percent in NHANES III.
PERCENTAGE OF CHILDREN WITH UNTREATED CARIOUS TEETH
TRENDS
70
65.4
1 Decayed Tooth 2 Decayed Teeth
59.1
60
3 Decayed Teeth 4 Decayed Teeth 5+ Decayed Teeth
50
37.5
40
34.7 29.1
30
25.2 21.3
18.6
20
16.5
15.3 10
15.8 14.2
16.1 6.6
6.2
8.3 3.6
3.3
1.6 1.5 0
NHANES I: At or NHANES III: At or Below the Poverty Below the Poverty Level Level
DISCUSSION
NHANES I: At the Poverty Level
NHANES III: At the Poverty Level
DATA SOURCE AND POVERTY LEVEL
Figure 3. Children 6 to 11 years old: percentage with specific numbers of carious teeth among those with untreated carious permanent teeth (First National Health and Nutrition Examination Survey, or NHANES I, 1971-1974,1,2 and Third National Health and Nutrition Examination Survey, or NHANES III,1988-19943). PERCENTAGE OF CHILDREN WITH UNTREATED CARIOUS TEETH
Our findings document the dramatic decline in untreated caries among children in the United States over a relatively short period. Overall, the number of untreated carious permanent teeth among children 6 to 18 years old dropped by 76.9 percent between NHANES I and NHANES III. Percentage decreases of 70 percent or more were achieved in all categories of age, sex, poverty and race. Absolute levels dropped to 0.5 carious teeth per child or fewer in almost all categories examined. The categories with the highest levels of untreated carious teeth in NHANES I experienced the largest absolute drops from NHANES I to NHANES III. The absolute decrease was a reduction of just more than one untreated carious permanent tooth per child. In 1991, the midpoint of the NHANES III survey, there were approximately 45,605,0004 children in this age category. Untreated caries has been reduced by nearly 50 million teeth in this age group. Although oral health differences based on poverty and race still exist, absolute differences
60 1 Decayed Tooth 2 Decayed Teeth
48.7
3 Decayed Teeth
50
41.5
4 Decayed Teeth
43.0
5+ Decayed Teeth
40
31.0
29.2
30
24.4 19.8 20
24.5
17.8 17.7 14.115.1
12.9
12.8
10.9
9.4
8.9
8.2
10
4.9
5.1
0
NHANES I: At or Below the Poverty Level
NHANES III: At or Below the Poverty Level
NHANES I: At the Poverty Level
NHANES III: At the Poverty Level
DATA SOURCE AND POVERTY LEVEL
Figure 4. Children 12 to 18 years old: percentage with specific numbers of carious teeth among those with untreated carious permanent teeth (First National Health and Nutrition Examination Survey, or NHANES I,1971-1974,1,2 and Third National Health and Nutrition Examination Survey, or NHANES III,1988-19943).
between poverty and racial categories in NHANES III were much smaller than those of 20 years earlier in NHANES I. In both NHANES I and NHANES III, black children experienced rates of untreated caries twice as high as those of their white counterparts. However, the
absolute disparity between black and white children decreased from 1.12 teeth in NHANES I to 0.24 teeth in NHANES III. Children living in poverty during the NHANES III period still exhibited more untreated caries in their permanent den-
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
1643
NUMBER OF UNTREATED CARIOUS PERMANENT TEETH
TRENDS
2.50
2.14
■
At or Below the Poverty Level
■
●
Above 300% of the Poverty Level
2.00
1.50
1.00
0.78
● 0.46 0.50
■ 0.11
●
0.00
NHANES I (1971-1974)
NHANES III (1988-1994)
DATA SOURCE
Figure 5. Average number of untreated carious permanent teeth among children 6 to 18 years old who were at or below the poverty level compared with those who were above 300 percent of the poverty level (First National Health and Nutrition Examination Survey, or NHANES I, 19711974,1,2 and Third National Health and Nutrition Examination Survey, or NHANES III,1988-19943).
tition than did children living above the poverty level. Nevertheless, these children experienced dramatic improvement in the percentage of teeth without untreated caries, the average number of untreated carious permanent teeth and the extent of untreated caries among those with the condition. As illustrated in Figure 5, the difference in the average number of untreated carious teeth in children at or below the poverty level and the average in those 300 percent above the poverty level narrowed substantially between NHANES I and NHANES III. The difference in the average number of carious teeth between the low and high ends of the poverty spectrum was 1.36 teeth in NHANES I. This disparity decreased to 0.35 teeth in NHANES III. The NHANES III data are nearly a decade old, so if the trends observed in these data continue, the current disparity
1644
may become even smaller.
major impact on the practice of dentistry in the United States as these surveyed children Dr. Brown is associate executive grow older. director, American The declines Dental Association, in untreated Health Policy Resources Center, caries may 211 E. Chicago Ave., reinforce the Chicago, Ill. 60611. Address reprint already requests to Dr. apparent Brown. shift5 from restorative to preventive dental services. Nevertheless, a question remains as to whether these declines in untreated caries will continue. Trends in caries as well as other oral health conditions merit careful monitoring during this period of change in dental diseases. ■
CONCLUSION
It is evident from the analysis presented here that although the condition of carious permanent teeth among children still exists and represents an oral health problem, it has diminished dramatically in both prevalence and extent across time for all poverty and race categories examined. There is no doubt that over the twodecade interval between NHANES I (1971-1974) and NHANES III (1988-1994), there has been a significant abatement of the prevalence of untreated carious permanent teeth among children 6 to 18 years old. Data presented here show that all segments of America’s child population have benefited from improved oral health. This is extremely good news for the nation’s children. The changes examined in this series of articles will have a
Mr. Wall is manager, Statistical Research, American Dental Association, Health Policy Resources Center, Chicago. Ms. Lazar is manager, Health Policy Analysis, American Dental Association, Health Policy Resources Center, Chicago. 1. U.S. Department of Commerce. National Technical Information Service, Division of Health Examination Statistics. National Health and Nutrition Examination Survey (NHANES I) 1971-1974. Hyattsville, Md.: National Technical Information Service; 1979. Dental Data Tape Catalog 4,235. 2. Thearmontree A, Eklund SA. Comparison between NHANES I and NHANES III: comparable NHANES I tooth and surface data (abstract 2076). J Dent Res 1999;78(special issue):365. 3. U.S. Department of Health and Human Services, National Center for Health Statistics. Third National Health and Nutrition Examination Survey, 1988-1994, NHANES III Examination Data File (database on CDROM). Hyattsville, Md.: National Center for Health Statistics; 1996. Public Use Data File Documentation Number 76,200. 4. U.S. Bureau of the Census. Statistical abstract of the United States: 1993. 113th ed. Washington, D.C.: Government Printing Office; 1993:16. 5. Brown LJ, Lazar V. The economic state of dentistry: demand-side trends. JADA 1998;129:1685-91.
JADA, Vol. 130, November 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.