6453名17～21岁青年人恒牙发育异常的调查

A survey of number and morphology anomalies in permanent teeth of 6 453 youths between 17 to 21 years old

目的调查青年人恒牙牙齿形态和数目异常的状况。方法2002至2004年对3所北京高校6453名17～21岁学生进行恒牙数目和形态异常的调查。对不同性别和不同牙位发育异常的患病率进行卡方检验,并对2种牙齿异常伴发的情况进行卡方检验。结果牙齿数目和形态异常的总患病率为16.07%。女性锥形牙或桶状牙、畸形中央尖和先天缺牙的患病率高于男性,差异有统计学意义(P<0.05)。牙内陷、锥形牙或桶状牙好发于上颌侧切牙,畸形中央尖好发于下颌第二前磨牙,融合牙和先天缺牙好发于下颌切牙,差异均有统计学意义(P<0.01)。锥形牙或桶状牙与先天缺牙伴发的比率高,差异有统计学意义(P<0.01)。结论各种牙齿数目和形态异常的患病率、性别差异和好发牙位与以往的研究基本相符。但锥形牙或桶状牙、畸形中央尖的女性患病率均高于男性。

Objective To investigate the status of number and morphology anomalies in the permanent teeth. Methods A survey of anomalies of number and morphology in the permanent teeth was carried out in 6 453 students who were 17 to 21 years old in 3 colleges during 2002 to 2004, Chi-square test was used to analyze the sex distribution, the involved tooth types and the associated anomalies. Results The overall prevalence of dental number and morphology anomalies was 16. 07%. The prevalence rates of peg-shape （conical） tooth, dens evaginatus and hypodontia were higher in females compared to males （P〈0.05）. Dens invaginatus and peg-shape teeth often involved maxillary lateral incisors, Dens envaginatus often involved mandibular second premolars. Fused teeth and hypodontia often involved mandibular incisors. The prevalence of hypodontia coincident with peg-shaped teeth was higher than other associated anomalies （ P〈0. 01 ）. Conclusions The result was similar to other investigations, but pegshape teeth and dens evaginatus were more prevalent in females than in males.