下牙弓后段可用间隙测量分析

Available Space Analysis of Lower Posterior Arch

目的研究下牙弓后段可用间隙生长变化特点。方法从符合纳入标准的初诊患者中随机选取 188例为研究对象 ,其中男性 76例 ,女性 112例。拍摄X线全颌曲面断层片 ,在X线片上沿牙合平面测量下颌第一恒磨牙远中表面切线到升支前、后缘之间的距离 ,使用SPSS/PC进行统计。结果①可用间隙生长量年龄、性别、牙合发育阶段差异有显著性 ;②可用间隙在安氏错牙合各类型之间差异无显著性 ;③升支宽度发育早期已经完成。结论可用间隙的临床预测应结合年龄、性别、牙合发育阶段等指标作综合评估。

Objective To study the growth changes of available space of lower posterior arch. Methods The sample consisted of 188 randomly selected subjects aged from 11 to 18 years, 76males and 112 females. The distance from the distal of lower first molar to the anterior border and also to the posterior border of the ramus was measured from orthopantomographams. All the data were analyzed by statistic methods. Results 1) The significant difference of available space between sexual groups,as well as that in different age groups and developmental stages of occlusion was found.2) No significant difference in Angle's malocclusion categories was showed.3) The width of ramus was attained at early stage. Conclusions The prediction of available space should be based on age,sex and stage of occlusion.