義務教育期間中における永久歯うしょくの追跡研究 多元配置累積法での分解による解析評価

Abstract

Dental caries in school children has not decreased to a level corresponding to the efforts made to prevent it. As the caries prevalence in permanent teeth is very high during the period of compulsory education, the effective caries prevention should be promoted during this period. Therefore, it is considered valuable to survey the real state of caries prevention and provide school dental health service according to the results of survey. Yearly observation of the changes in oral conditions of same subject gives reliable results. In this study, I made a survey of dental caries prevalence on permanent teeth of school children for 9 years from the age of 6 years until they graduated from middle high school, and I preformed cumulative analysis of variance of multiple-way layout of the results. The decomposition of factors was also followed to exhibit the difference in caries prevalence between different kinds of teeth or tooth groups which have not completely analyzed been so far.I obtained the following results.Caries prevalence during the period of compulsory education increased by 2.85 carious teeth per year and its regression equation was as follows;Y (DMF) =2.85X (school year) -0.78The tendency of caries prevalence in different kinds of teeth or tooth groups was varied and the dental health care for younger and older primary school children and middle high school children should be focused on the first molar, incisor of upper jaw and premolar, and second molar, respectively. Moreover, the comparison of these results with those of commonly used cross sectional studies showed much similarity. I also suggest that the caries prevalence of the first molar could represent the tendency of the whole dentition.The statistic analysis used for the first time in this kind of survey was useful to analyze yearly data or the data from different kinds of teeth or tooth groups.