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%.
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%.