Oral Epidemiology

Dental caries status of Chinese children in Johannesburg, South Africa p. M. MGINNES AND E. VIEIRA Medical Research Councit, University of the Witwatersrand Dental Research Johannesburg, South Africa •

Institute, .

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Mclnnes, P. M. & Vieira, E.: Dental caries status of Chinese children in Johamiesburg South Africa, Community Dent. Oral Epidemiol. 1979: 7: 170-173. '

Abstract — The purpose of this study was to determine the dental health status of a representative sample of Johannesburg Chinese schoolchildren, all 250 attending the only Chinese school in the city. In 18 preschoolchildren, 3-5 years old, 16.7 % were caries-free mean dmft was 7.1 + 5.8 and labial earies was present in 33.3 %. In 165 primary schoolchildren aged 5-16 years, the mean dmft was 5.0 + 3.2 with 20 % of the primary dentition caries-free and the mean D M F T was 2.4 ± 1.9. 4.8 % oi the primary schoolchildren were caries-free. In 67 high school pupils of 11-17 years, 4 . 5 % were caries-free and the mean D M F T score, was 7.1 ± 3.9. Caries prevalences among the Chinese were sitiiilar to corresponding groups of children of Chinese immigrants in the United Kingdom and Malaysia

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Key words: dental earies. P. M. Mclnnes, Dental Research Institute, University of Witwatersrand, 1 Jan Smuts Avenue, 2001 Johannesburg, South Africa. ..-, , ,

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Accepted for publication 10 December 1978.

The Chinese community in Johannesburg, South Africa, is a closely knit comm.unity which has maintained much of an oriental way of life in the midst of Western culture. The present community has developed from sporadic immigration up to 1950 with the arrival in 1891 of Cantonese traders, from Madagascar and Mauritius. Until the commencement of the present study, no research had been carried out on the oral health status of the community. Interest in this group of people arose after studying a paper by VARLEY & GOOSE (10), who reported results of a svirvey in children of immigrants living in Liverpool. They found that the children of Chinese immigrants had higher DMF values than corresponding groups of White or Negro children. The present investigation was undertaken to determine the dental health status of a representative sample of Chinese schoolchildren in Johannesburg. 0301-5661/79/030170 $02.50

©

1979

MATERIAL AND METHODS The children studied attended the Kuo Ting Chinese school, the only sehool of its type in Johannesburg. All 250 children in the school were exatnincd with the per.. mission of the sehool principal. They were divided into three groups: a preschool group consisting of 18 pupils; a pritnary school group comprising 165 pupils; and a high sehool group containing 67 pupils. The children were of mixed socioeconomic class. The examinations were carried out over 3 days and males and females were examined in random order. The children sat on an upright chair in a classroom, in good natural light augmented by artificial light. Their dentitions were examined by one investigator using a mirror and sharp probe and any suspicious area, pit or fissure, in which the probe stuck, was recorded as carious. Teeth were considered erupted once the entire occlusa! surface was exposed and could be probed. Teeth with primary decay and those with fillings and secondary decay were designated decayed (D/d). Labial caries was defined as caries on the labial surface of a maxillary or mandibular incisor tooth. Rampant caries was recorded as caries involving more than 25"% of the dentition (9). ^

Munksgaard, Copenhagen

Caries in Chinese 171 SIMEAN-7'I

1

28-

B CHINESE LLJ

24-

Q

20-

>CHII

•WHITES

16

RAMPANT CARIES(DIVIFT>7)

128

. 1 Fig. I. Histogram showing percentage frequency distribution of dmft and rampant caries (dmft > 5) in 18 Chinese preschoolehildren (3-5 years) and 111 White preschoolchildren.

The observations were transferred onto IBM punchcards and statistical analysis was carried out in an IBM 370/158 computer using the Statistical package for the social sciences (7). The statistical tests used wei'e the Student's t-test and the chi-square test; the level of significance chosen was P < 0.01.

RESULTS PRESCHOOLCHILDREN Eighteen children were examined of whom seven were girls and 11 boys. They ranged in age from 3 to 5 years with a mean value of 4.3 ± 0.5 years. Their dmft values ranged from 0 to 20 with a

RAMPANT CARIES (dmft a 5) Q X

0

1 2

3

1

11

1 11 IL 16 17

dmft Fig. 2. Histogram showing percentage frequency distribution of dmft and rampant caries in 165 Chinese primary schoolchildren (5-16 years). ~ ' '' '

4n0

1 2

3

4

5

6

7

8

10

12

DMFT Fig. 3. Histogram of percentage frequency distribution of DMFT and rampant caries in 165 Chinese primary schoolchildren (5-16 years).

mean value of 7.1 ± 5.8 and 16.7 % of the children were caries-free (Fig. 1). Six children had labial caries and the mean number of teeth requiring treatmetit was 5.1 ± 5.4. Rampant caries was present in 61.1 % of the cliildren. No statistically significant differences were found between the prevalences of caries in the small group of males atid females. Fig. 1 shows, in histogram fortn, a comparison of the dmft indices for the Chinese children and for a corresponding group of White preschoolehildren iti Johannesburg (5). The mean dmft in Whites (4.9 ± 4.4) was higher than that of the Chinese group but this was not statistically significant. PRIMARY SCHOOLCHILDREN . ' In the primary school 165 children, 63 females and 102 males, were studied. They ranged in age from 5 to 16 years with a mean age of 8.6 ± 2.2 years. The dmft values ranged from 0 to 19 with a mean value of 5.0 ± 3.2 (Fig. 2). Twenty percent had no caries in their remaitiing primary teeth but rampant caries was present in 50.8 % of the children. In the permanent dentition the DMFT values ranged from 0 to 12 with a mean value of 2.4 ± 1.9, while 4.8 % of the children were caries-free (Fig. 3). There was no significatit difference betweeti the DMFT values for males and females but males had a higher dmft than females {P < 0.005). Thirty-one children (18.8%) had labial caries oftheir remaining primary incisor or canine teeth.

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MGINNES AND VIEIRA Table 1. Details of the decayed, missing and filled teeth in the primary and permanent dentitions

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RAMPANT CARIES (DMFT>7)

13

Group

1211-

9Q

I

o

8.

ni

f

8 27 82 482 103 200 1 0 2

Preschool Primary school High school

10-

on

d

D

M

0 369 231

0 0 34 91 47 190

F

765-

!t

4 32 13

4

5

6

7

8

9

10

11 12

13

16

17

DMFT

Fig. 4. Histogram of percentage frequency distribution of DMFT and rampant earies in 67 Chinese high school children (11—17 years). the number of teeth per child ranging from 1 to 6 with a mean of 0.5 + 1.2. There was no significant difference between the labial caries prevalences iti females and males. The tiumber of teeth requiring treatment ranged from 0 to 17 with a mean value of 5.0 ±3.9 teeth. HIGH SCHOOL CHILDREN In the high school 67 pupils, 22 females and 45 males, were examined. They ratiged in age from 11 to 17 years with a mean age of 14.6 ±1.5 years. DMFT scores ranged from 0 to 17 with a mean value of 7.1 ± 3.9 and 4.5 % were caries-free (Fig. 4). Rampant caries (DMFT > 7 ) was tioted in 49.3 % of the children. There were no statistically significatit differences between males atid females in any of the results in the high school group. Details of the numbers of decayed, missing and filled teeth for the three groups are shown in Table 1.

Primary schoolchildren — The caries prevalence observed iti tliis group was much as had been expected. The values recorded cannot be compared with similar groups of White children in present-day Johantiesburg as no surveys iti that group have been published. However, VARLEY & GOOSE (10), in a survey of jutiior school Chitiese children in Liverpool, found a mean DMF value of 1.8 ± 0.4 for boys and 2.2 ± 0.5 for girls. The DMFT values for the Johantiesburg Chinese childreti were 2.8 ± 2.0 for boys and 3.0 ± 2.7 for girls. Using the chisquare test, the DMFT value for boys in Johannesburg was significantly higher than their counterparts in Liverpool ( F < 0.001) but, as it was not possible to determine the age groups examined by VARLEY & COOSE (10), this difference should be treated with reserve. All extensive dental health survey was undertaken iti Malaysia by YASSIN & Low (11). They studied Malay, Chinese and Indian children atid found a distinct variation in the caries experietice in the permanent teeth of these groups. The caries prevaletice was highest among the Chitiese children, beipg about twice the prevalence in the Malay and Indian children. The authors postulated the possibility of a racial variation in caries susceptibility as ati analysis of factors cotitributing to the racial variation showed that dietary itifluence was not the otily prevailing factor. ^ Table 2. Comparison between caries prevalences in primary dentition in Malaysia and Johannesburg ' Age in years

DISCUSSION Preschoolehildren — The observations in this section of the study suggest that the caries prevalence among Chinese preschoolehildren may be higher thati among their White counterparts. Examitiation of a larger sample of Chinese children is needed to establish this.

6 7

8 '

9 10 11

12

Malaysian Chinese (11) Present study dif (mean ± s.d.) dmft (mean ± s.d.) ,. "\

6.5 5.3 3.4 2.1 1.0 0.4 ' 0.1

± 3.1 ± 3.0 ±2.6 ± 2.2 ± 1.6 ±1.0 ± 0.5

9.1 7.9 5.5 4.6 2.2 1.5 0.3

± ± ± ± ± ± ±

4.5 4.1 2.4 3.7 2.1 1.9 0.6

Caries in Chinese 173

I Table 3. Comparison between caries prevalences in permanent dentition in Malaysia and Johannesburg Age in years 6 7 8 9 10 11 12 13 14 15 16 17

Malaysian Chinese (1 1) Present study DIF (mean ± s.d.;1 DMFT (mean ± s.d.) 1.3 1.9 3.0 3.6 4.2 5.3 5.9 6.1 6.5 7.0

± 1.4 ± 1.8 ± 2.2 ± 2.6 ± 3.1 ± 3.7 ± 3.9 ± 4.2 ± 4.5 ± 4.9

'• ;

7.3 ± 4.5

-'

7.4 ± 5.5

1.2 2.1 2.4 3.0 3.8 4.1 5.5 6.6 4.9 7.8 7.8 7.9

± 1.4 ± 1.7 ± 1.3 ± 1.8 ± 1.3 ± 2.1 ± 4.3 ± 4.1 ± 3.4 ± 4.4 ± 3.7 ± 4.4

groups did tiot differ significantly from those of their White counterparts. Differences in caries prevalences in ethnic groups living in the same areas may be due to variations in dietary pattertis atid to genetic factors (1-3,6), JACKSON (4) in particular supports the genetic theory. From the results of the presetit study it is not possible to comment oti these points.

REFERENCES 1. CLE.\TON-JONES, P., RICHARDSON, B.D., MCINNF.S, P.

M. & FATTI, L . P . : Dental earies in South African white children aged 1-5 years. Community Dent. Oral Epidemiot. \91%: 6: 78-81 2. CRKiGttTON, W. E.: Dental caries experience of Negro and Caucasian children in Portland, Oregon. / . Dent. Child. 1969: .36; 139-143 3. INIWNTE, P . F . & RUSSELL, A. L.: An epidemiologic

The results of YASSIN & Low (11) are compared with those in the present study in Tables 2 and 3. In the primary dentition the results in our study are higher than those iti Malaysian Chitiese. As the numbers of children in each of YASSIN & Low's (11) age groups were not published, it is not possible to analyze the data statistically. The decreasing caries prevaletice iti the primary dentition iti both groups is, of course, due to exfoliation of primary teeth as age increases. In the permaiietit dentitioti, DMFT values in the present study were lower than those of YASSIN & Low (11) in children up to 12 years of age, but at 13, 15, 16 and 17 they were slightly higher. High school children - RETIEF, CLEATON-JONES & WALKER (8), in a survey on 16- and 17-year-old White pupils in Johannesburg, found mean DMFT values for males atid females of 8.9 atid 11.1 respectively. To achieve comparisoti, the data of the Chinese children aged 16 and 17 years were analyzed. There were 19 children in this age group, 12 males and 7 females. In the male group the meati DMFT was 7.7; for the females it was 8.6. The DMFT of these small

study of dental caries in preschool children in the United States by race and socioeconomic level. / . Dent. Res. 1974: 55: 393-396 4. JACKSON, D . : Caries initiation: inadequacies oj the acid theory. ISRF/CEFS International Meeting, Paris, France. International Sugar Research Foundation, Bethesda 1977 5. MCINNES, P . M . : Rampant caries and oral microbiology in white South African preschool children. / . Dent. Res. 1911: 56: A45 6. MENEZES, D . M . : A dental health study of children attending dental hospitals in Rangoon and Birmingham. Community Dent. Orat Epidemiol. 1974: 2: 20-25 7. NtE, N. H., HUM., C . H . , JENKINS, J. G., STEmBRENNER,

K. & BENT, D . H . : Statistical package jor the social sciences. 2nd ed. McGraw-Hill, New York 1975 8. RETUSF, D . H . , CI.E.\TON-JONES, P. E.

& WALKER,

A. R. P.: Dental caries and sugar intake in South African pupils of 16 to 17 years in four ethnic groups. Br. Dent. J. 1975: 138: 463-469 9. RICHARDSON, B . D . & CLEATON-JONKS, P. E.: Rampant

caries and labial caries - synonyms? S. Ajr. Med. f. 1977: 5/.- 527 10. V.\RLEY, T. F. & GOOSE, D . H . : Dental caries in children of immigrants in Liverpool. Br. Dent. ]. 1971: 130: 27-29 11. YASSIN, I. & Low, T.: Caries prevalence in different racial groups of schoolchildren in West Malaysia. Community Dent. Oral Epidemiol. 1975: 3: 179-183