髁突高位切除术对下颌骨位置的影响

目的:探讨髁突高位切除术后下颌骨的位置变化。方法:收集武汉大学口腔医学院就诊的髁突肥大患者10例。患者术前均接受临床及影像学检查及双侧髁突Tc99-MDP计算机体层扫描(SPECT)检查。所有患者均接受髁突高位切除术,平均随访时间9.6月。下颌骨位置变化评价方法:1)矢状位:比较侧位头影测量上测量术前术后SNA、SNB及ANB角的变化。2)冠状位:比较正位头影测量术前术后上、下颌切牙点至Y轴的距离。结果:侧位头影测量显示术后SNA无显著变化(P>0.05),SNB显著减小(P<0.05),ANB显著增加(P<0.05)。正位头影测量显示上切牙点至Y轴的距离无显著变化(P>0.05),下切牙点至Y轴的距离显著减小(P<0.05)。结论:髁突高位切除术后下颌骨在矢状位及冠状位上发生向后和向患侧的移位,此种移位有利于髁突肥大所致偏颌畸形的矫正。

Mandible Shift after the Condylectomy

Objective:To discuss the mandible shift after condylectomy.Methods:10 patients(4 males,6 females)with condylar hyperplasia had been collected in the Department of Maxillofacial Surgery of the School of Stomatology,Wuhan University.All patients had made the standard clinical and radiography examinations,as well as the Preoperative Tc99-MDP single photon emission computed tomography(SPECT)examination.Then,the average follow-up interphase was 9.6 months.Estimate methods were:1)Sagittal section:preoperative and postoperative,the angle changes with SNA,SNB and ANB on the lateral cephalometric X-Rays.2)Coronal section:measuring the separation of the joint of upper and lower incisor to the Y axis on the positive cephalometric X-Rays.Results:Regarding from the lateral cephalometric X-Rays which taken after the operation,SNA has less change(P>0.05),but SNB decreases remarkably(P<0.05),while ANB increases significantly(P<0.05).The positive cephalometric X-Rays shows the separation has no change between the upper incisors and Y axis,but a significant decreasing happens between lower incisors and Y axis(P<0.05).Conclusion:The mandible shifts backwards on the sagittal section,and also to the affected side on the coronal section.This kind of shift is advantaged to the orthodontics of the deflected malocclusion in condylar hyperplasia.