隐裂磨牙牙尖斜度的三维重建测量研究

A measurement after 3D-reconstruction to study cuspal inclination of the cracked molars

目的:研究牙尖斜度的三维测量方法,从牙体解剖方面探讨磨牙隐裂病因。方法:隐裂组、对照组磨牙模型经螺旋CT扫描后,数据图像以DICOM格式直接输入Efilm1.8.3软件进行牙尖斜度及牙尖斜面夹角三维重建测量。结果:隐裂组的近中颊、舌尖牙尖斜度均数都大于对照组,前者相差9.02°,后者相差9.29°;牙尖斜面夹角均数小于对照组,相差17.34°。成组t检验两组的近中颊、舌尖牙尖斜度,牙尖斜面夹角均有显著性差异(P<0.01)。结论:牙尖斜度的大小是磨牙隐裂重要病因之一,牙尖斜度越大,牙尖斜面夹角越小,隐裂发生的可能性越大。

Objective： To study a 3D-measurement for cuspal inclination and evaluate the anatomical etiology of the cracked molars. Method-A case-control study was conducted （14 cracked-molar dies as a case group and 22 normal-molar dies as a control group）. Images were obtained by spiral CT scan and immediately imported into Efilml. 8.3 software measure cuspal inclination and cuapal incline angle after 3D-reconstruction. Result： The mean of mediobuccal cuspal inclination angles in cases was bigger than that in controls , so was the mean of mediolingual ones. The former＇s difference was 9.02° and the latter＇s was 9.29°. Both showed statistically significant difference（a = 0.05, P 〈 0.01 ）by the independent test. While the mean of cuspal incline angle in cases was smaller than that in controls, the difference was 17.34°which also showed statistical significance. Conclusion： Cuspal inclination was one of the important anatomical factors in the etiology of CTS in molars . The bigger the inclination and the smaller cuspal incline angle , the more likely the presence of CTS.