Cohort Analysis on the Sex Differences in Caries Morbidity of Parmanent Teeth

Abstract

To elucidate precisely the sex differences in caries morbidity, they should be observed by post-eruptive tooth age on the individual kind of teeth under the constant sugar consumption per year per head after eruption (p) based on the epidemiological principles in dental caries attack. Authors analysed 983 boys and 778 girls who were longitudinally observed for 3 to 6 years from 1970, using the criteria on caries of WHO, the material collected by K. Katayama. The sugar consumption during the period under survey was in stable condition of about 27kg per year per head. Analytic methods were shown in detail in the previous paper^aand followed by the same approach. Cumulative number of carious teeth up to the post-eruptive tooth age x per initial 100 teeth (ΣCx) is applyed for this study. The main results of the caries indices are shown in Table 1 and 2. Statistical test of sex differences in ΣCx by ordinary chronological age is resulted in Table 3, and results of same test by post-eruptive tooth age are shown in Table 4. Cochran's Criterion Method is applied to compare the overall difference in ΣCx of every kind of teeth between the sexes, and the results are shown in Table 5.
With reference to frequently used caries indices, children of Group A are analysed, as shown in Table 6. Among the higher risk group of teeth in caries attack, females show higher risk than males during the early post-eruptive tooth ages and then the differences narrow in advanced ages. Two ΣCx curves of male and female in this paper show the same pattern as those of low and high risk groups in caries attack, derived from epidemiological principles advocated by M. Takeuchi. It gives the fact that the difference in sex of caries morbidity is existed, but it lies within a minor magnitude.
^aKatayama K.: Caries incidence pattern by post-eruptive tooth age in permanent teeth, J. Dent. Hlth, 28; 220-243, 1978