Abstract
Conducting a survey on dental caries affecting primary and junior high school children in the cities of Sapporo, Nagoya, Kumamoto and Nagano and farm communities in their neighborhoods, this author studied regional variations in the rate of caries occurrence in permanent teeth and the rate of treated caries-affected permanent teeth.
Comparison of the rates of caries occurrence in permanent teeth in the four regions showed much similarity between urban and rural areas and between the sexes, with Nagano showing an apparently higher rate but little difference noted among the other three regions.
These regional differences can hardly be considered to derive from climatic or geographical conditions but appear to come from the local cultural environment characteristics of the schools chosen for the survey.
As for urban-rural differences in dental caries occurrence, it was found that, in Sapporo and Nagoya, in both sexes, higher rates were seen in urban communities than in rural areas, whereas in Kumamoto and Nagano, in both sexes, the latter showed higher rates than the former.
Differences in the rate of treated dental caries were most conspicuous. In each region, in both sexes, higher rates were always seen in urban areas than in rural communities.
