A survey of hypodontia in Japanese orthodontic patients.

摘要: Introduction: The purpose of this retrospective study was to assess the prevalence and distribution hypodontia in permanent dentition, excluding third molars, a sample Japanese orthodontic patients. Methods: Orthopantomograms 3358 patients (1453 boys 1905 girls) between ages 5 15 years were examined for evidence hypodontia. Results: 8.5% (7.5% boys, 9.3% with no statistically significant difference sexes. average number missing teeth per child 2.4 (2.5 girls). Most (76.3%) children either 1 or 2 (77.1% 75.7% advanced 10.1% (11.0% 9.7% most commonly mandibular second premolars, followed by maxillary lateral incisors, premolars; minor differences order existed among groups classified teeth. Symmetrical predominant, symmetrical premolar agenesis. No consistent finding obtained as which jaw had more similar right left sides dental arches each group children. Anterior tooth agenesis predominant hypodontia, posterior increased severity. Conclusions: distinct characteristic population compared other populations higher both incisor