下颌角切除术前、后颅面骨骼和咬肌CT影像的三维测量

目的 探讨下颌角截骨整形术前、后颅面骨性结构和咬肌的变化.方法 随机选取下颌角肥大者18例,于术前、后分别做三维CT检查,并对颅面结构进行三维测量,采用自身对照进行配对资料t检验.结果 下颌角截骨整形术后下颌角角度增加(15.96±4.39) °、下颌骨角区最大宽度减少(7.72±1.83) mm、升支长度减少(8.01±2.92) mm、下颌角间距减少(4.35±1.94) mm、下颌角外翻角减少(8.76±8.02)°、下颌骨扩展角度减少(3.91±1.86)°、咬肌厚度减少(2.99±1.07) mm、咬肌宽度减少(2.65±1.73) mm、咬肌长度减少(6.23±2.29) mm、角区面宽度减少(5.29±2.01) mm,上述测量指标与术前比较差异有统计学意义(P＜0.05).结论 下颌角截骨整形术后颅面骨骼三维测量与术前比较差异有统计学意义(P＜0.05),咬肌有萎缩现象,因此术中一般不需切除咬肌.

3-dimensional CT cephalometry before and after mandibular angle osteotomy and its clinical significance

OBJECTIVE: To investigate the change of skelton structure and masseter after mandibular angle osteotomy and its clinical significance in preoperative design. METHODS: 3-dimensional CT cephalometry was performed before and after surgery in 18 cases of prominent mandibular angle. RESULTS: Pre- and post-operative data were compared. Significant differences between the pre- and post-operative data were found in the mandibular angle, the distance between mandibular angle, length of ramus, ectropion angle of mandibular angle, triangle Go-Me-Go, the thickness, width and length of masseter. CONCLUSIONS: It indicates the skelton structure is changed and some kind of atrophy happens in the masseter after operation. So we suggest partial resection of masseter should be unnecessary for mandibular angle osteotomy.