Community differences in caries prevalence in deciduous teeth were investigated. The Community Organization Data Base System (CODB) includes the data of 3-year-old children's dental examinations from 112 communities (cities, towns and villages) in Niigata prefecture in 1983, 1984 and 1985. This CODB also includes the data of 141 items concerned with community characteristics. Multiple regression analysis was used to find the factors that have an influence on the caries prevalence in deciduous teeth in each community.
The dmft indices on an average for these 3 years were distributed from 1.32 to 7.06 in 111 communities, ignoring one community in which the number of 3-year-old children was less than 10. There was a fivefold difference between the maximum value and the minimum. The pattern of caries prevalence was similar in each community belonging to the same county. It appears that the county has a homogeneous life environment that affected the caries of deciduous teeth.
Community characteristics were closely related to the caries prevalence (multiple correlation coefficient=0.51, p<0.01). Five items from these community characteristics were highly correlated to the caries prevalence. These were percentage of children receiving 1.5-year-old dental examination, degree of self-sufficiency for medical care in a community, numerical rating of the health insurance for dental treatment, annual family income and mean dmft index of 3-year-old children in the county exclusive of the subject community
It appeared that the lower caries prevalence of deciduous teeth in a community had close relationship to urbanization of the community.