关键词: [关键词] 先天性牙齿缺失, 多生牙, 埋伏牙, 融合牙, congenitally absent tooth, supernumerary tooth, impacted tooth

Abstract: Objective To investigate prevalence and distribution of tooth agenesis (congenitally absent teeth, supernumerary teeth, impacted teeth and fused teeth) in a sample of patients who had malocclusion in Jiangsu area to support clinical work. Methods 1012 orthodontic patients at the first visit in Jiangsu Provincal Stomatological Hospital (416 males, 596 females, aged between 4 to 50 years) from June to September of 2012 were collected. Based on the radiography data, clinical examination and medical history, analyze the prevalence of congenitally absent teeth, supernumerary teeth, impacted teeth and fused teeth and their distribution in dentition Results The prevalence of congenitally hypodontia was 8.99 % (excluding the third molars), the most frequent missing tooth position was lower incisor. The prevalence of supernumerary teeth was 2.57%, most of them were located in palatal of upper central incisors and were impacted. The prevalence of impacted teeth was 8.79%, occurred most frequently in the maxillary canine. The prevalence of fused tooth was 0.69%, all cases were in mandibular anterior teeth. Conclusion There’s a high prevalance of tooth agenesis in orthodontic patients in Jiangsu Province, and congenitally absent teeth were most common, whose prevalence was significantly higher than average result in previous epidemiological studies. Impacted teeth come the second. Supernumerary teeth and fused teeth follow.