成都地区正常人群临床牙冠中心高度的研究

A Study on the Center Height of Clinical Crowns for the People with Normal Occlusion in Chengdu Area

目的 了解成都地区正常人群临床牙冠中心高度的分布规律并结合曲线的规律对全程式化预成序列托槽的粘接高度进行探讨。方法 符合纳入标准的未接受过正畸治疗的成都地区 18～ 35岁正常者 75例为研究对象。其中男性 36例 ,女性 39例。测量样本临床牙冠中心高度 ,分析正常人群的临床牙冠中心高度的分布规律 ;测量下颌临床牙冠中心点连线和Spee曲线的曲度并通过相关分析检测二者的相关性。结果 ①成都地区正常人群临床牙冠中心高度呈正态分布且标准差较小 (<0 .5mm) ;②不同性别间各同名牙临床牙冠中心高度测量值无统计学差异 (P <0 .0 5 ) ;③下颌临床牙冠中心点连线与Spee曲线的曲度具有高度相关性 (γ =0 .986 ,P <0 .0 0 0 1)。结论 ①成都地区正常人群各同名牙临床牙冠中心高度的差异较小 ;②男女间各同名牙临床牙冠中心高度无显著性差异 ;③提供了一套适合成都地区人群的全程式化预成序列托槽矫治器临床粘接高度参考值 ;④一般情况下 ,应该按照临床牙冠中心点的高度粘接全程式化预成序列托槽。在一些特殊情况下 ,应该对托槽粘接高度进行适当的调整。

Objective The purpose of this study was to investigate the center height of clinical crowns and the difference among individuals, together with the regularity of the Spee curve in mandible and compensating curve in maxilla for the people with normal occlusion in Chengdu area.Methods The data were derived from systematically collected people with normal occlusion in Chengdu area, including 36 males and 39 females (ranged from18 to 35 years ). The values of center height of clinical crowns, the depths of Spee curve and curve formed by the center of clinical crowns in mandible were obtained by measurement. Afterwards, the distribution of the center height of clinical crowns was analyzed, as well as the depth of curve formed by the center of clinical crowns in mandible and its correlation with depth of Spee.Results (1) The distribution of the center height of clinical crowns accord with normal distribution and the standard deviation was minor(<0.5 mm); (2)There was no statistical difference between male and female for the center height of clinical crowns;(3)The depth of curve formed by the center of clinical crowns in mandible and the depths of Spee curve showed highly correlation(γ=0.986,P<0.000 1).Conclusion (1) The difference of the center height in clinical crowns among individuals with normal occlusion in Chengdu area was minor; (2) There was no significant difference on the center height in clinical crowns between male and female; (3) Provide a recommended bracket placement chart suitable for people of Chengdu area in clinical practice; (4) The brackets of the pre-adjusted appliance should be placed in the center of clinical crowns, despite some adjustment are needed in some special circumstances.