An epidemiological study of supernumerary primary teeth in Japanese children: a review of racial differences in the prevalence.

OBJECTIVE

To clarify the prevalence of supernumerary primary teeth in Japanese children, we evaluated this prevalence in a sample of 8122 children aged 3-6 years. Furthermore, we undertook a statistical comparison of the findings of the present study with those of previous investigations on the prevalence of supernumerary primary teeth in Japanese, Chinese and Caucasian children.

SUBJECTS: The subjects used in the study consisted of 8122 children aged 3-6 years (4102 boys and 4020 girls). The children were examined in kindergartens.

METHODS

The prevalence of supernumerary primary teeth was recorded by visual inspection. Statistical analysis was carried out using the chi 2 test.

RESULTS

Four cases of supernumerary primary teeth were found among the children examined, and thus the prevalence was 0.05%. All of the supernumerary primary teeth were located in the maxillary lateral incisor area.

CONCLUSIONS

The prevalence in a sample of 8122 Japanese children was 0.05% and that in a combined sample of 65,068 Japanese children was 0.06%.