Abstract
There has been no nation wide research on dental health in 3-year-old children by municipality. Moreover, a problem arises when comparing the results among areas with different populations ; in an area with a small population, the dental caries prevalence rate is sharply affected by the members. This study was performed to calculate the empirical Bayes estimator of the dental caries prevalence rate in 3-year-old children of various municipalities, to draw illness maps of the prevalence rate, and to then compare the prevalence rates among areas on the illness maps. Moreover, the correlations between the estimator and the dental health indices were examined after adjusting for social background factors. Results were obtained for 3,1 12 municipalities in 1998, and data were collected for all municipalities (3,224) in 2000. Regional differences between the prevalence rates of 1998 and 2000, and a 2-year reduction of the prevalence rate were found using the illness maps. Multiple linear regression analysis showed that the estimator was greatly affected by better education, total fertility rate, kind of industry, and unemployment rate (partial correlation coefficient = -0.424, 0.214, - 0.204, and 0.149, respectively) The frequency of dental health guidance had a small influence (partial correlation coefficient = -0.067) (p<0.001). Regional differences between the dental caries prevalence rates in 3-year-old children were found using the illness maps of the empirical Bayes estimator. The frequency of dental health guidance tended to decrease the prevalence rate slightly.
