正畸前拔牙对髁突位置影响的X线头影测量研究

[目的]了解正畸治疗前拔牙与未拔牙病例治疗前后髁突位置相对于颅底位置的变化情况。[方法]利用张口型头颅定位侧位片与正中咬合头颅定位侧位片相结合的方法,对120例(拔牙86例,未拔牙34例)的正畸治疗病例进行头影测量研究。[结果]拔牙组病例中,治疗后髁突的位置相对于颅底的位置有向下向后移位的趋势,而未拔牙组病例中,治疗后髁突的位置相对于颅底的位置有向下向前移位的趋势,但两组之间的差异无显著性(P>0.05)。[结论]本研究的结果尚未能证明正畸治疗前拔牙对髁突相对于颅底位置有影响。

Cephalometric Roentgenographic Study on the Effect of Pre-orthodontic Extraction on the Position of Condyle

[Objective] To evaluate the change of the position of condyle relative to cranial base in patients treated with or without extraction. [Methods] 120 patients(86 with extraction, 34 without extraction) were studied by cephalometric analysis. Two lateral cephalograms were taken, one in centric occlusion and the other with the mouth wide open. This could provide greater accuracy and reliability in obtaining the image of condyle on lateral cephalogram with centric occlusion. [ Results ] Condyle moved posteriorly and inferiorly in extraction group and moved anteriorly and inferiorly in nonextraction group, but statistical difference was not significant ( P > 0. 05) between two groups. [Conclusion] This study does not indicate that the position of condyle relative to the cranial base is affected by pre-orthodontic extraction.