The prevalence of congenitally missing permanent teeth in Japanese children: A survey conducted in south-west area of Kanto district

Abstract

The purpose of this study was to investigate the prevalence of congenitally missing permanent teeth in Japanese children residing in south-west area of Kanto district in recent years. Panoramic radiographs taken for dental treatment between 1990 and 2007 were used to evaluate the congenitally missing permanent teeth excluding the third molar. The participants of this study consisted of 2,125 children aged between 7 and 20 years. The congenitally missing teeth were observed in 251 participants (11.8%). The majority of the participants (114) presented with only one tooth missing, and there was a general tendency that the number of participants gradually decreased as the number of missing teeth increased. A total of 539 teeth were congenitally missing, and mandibular second premolar was the most frequently missing tooth (153 teeth), followed by mandibular lateral incisor (86 teeth), maxillary second premolar (71 teeth), maxillary lateral incisor (61 teeth). Only one missing tooth (114 participants) was found most frequently in mandibular lateral incisor (30 participants), followed by mandibular second premolar (28 participants). There was a tendency that congenitally missing teeth occurred symmetrically; especially most of the participants who had two missing teeth (80 in 88 participants) were symmetrically missing. The prevalence of congenitally missing permanent teeth in this study was 11.8% and it was comparable to those reported in previous studies of Japanese population evaluated using panoramic radiographs.