摘要
本文调查了北京地区青少年先天缺失牙和多生牙的发生率、好发部位 ,探讨先天牙齿数目异常与人类进化之间的关系。观察和分析了 4 2 9名全颌曲面体层X线片 ,年龄为 12— 2 3岁 ,均无恒牙拔牙史或牙齿损伤史。结果表明先天缺失牙 (包括第三磨牙 )的发生率为 4 2 19% ,第三磨牙的缺失发生率为 35 4 3% ,缺失牙的好发部位依次为 :上颌第三磨牙、下颌第三磨牙、下颌第二双尖牙、下颌中切牙、上颌第二双尖牙等 ;多生牙发生率为 3 5 0 % ,好发部位是上颌切牙区。牙齿先天缺失在人群中的发生率明显高于多生牙 ,缺失牙主要发生在功能相对弱的牙位上 ;遗传因素对牙齿数目异常起主导作用。在人类进化过程中 ,缺失某些牙齿是咀嚼器官退化的趋势 。
The purpose of this study is to investigate the incidence and mostly happened area of the congenitally missing teeth and supernumerary teeth in Beijing adolescent in order to approach the relation between the anomaly of tooth number and human evolution. Subjects and methods:429 panoramic radiographs were observed and analyzed,163 males and 266 females, aged 12—23 years. None of permanent teeth have been extracted or hurted. Result: The incidence of congenitally missing permanent teeth (including third molar) is 42 19%.The incidence of missing third molar is 35.43%.The mostly happenedmissing teeth are maxillary third molar, mandibular third molar , mandibular second premolar, mandibular median incisor, maxillary second premolar etc. the incidence of supernumerary teeth is 3.50%, supernumerary teeth mostly happened are maxillary incisors. Conclusion: The incidence of missing teeth is higher than that of supernumerary teeth.Missing teeth mostly were found are the ones which have weaker function. The anomaly of tooth number is mostly due to hereditary factors. Congenitally tooth missing reflexes one of the evolutionary tendencies of the masticatory organ. The occurence of supernumerary teeth is a phenomenon of recapitalation.
出处
《人类学学报》
CSCD
北大核心
2003年第2期145-149,共5页
Acta Anthropologica Sinica
