下颌升支矢状劈开截骨牵引成骨术矫治半侧颜面短小畸形

Sagittal split ramus osteotomy combined with intraoral distraction osteogenesis for hemifacial microsomia

目的探讨在下颌牵引成骨术中应用矢状劈开截骨术式治疗半侧颜面短小畸形的方法和临床效果。方法2013年1月至2015年10月，对7例半侧颜面短小畸形患者术前进行数字化三维模拟，设计手术方案，标明下颌神经管与牙胚的位置。术中应用矢状劈开截骨术式结合内置式牵引成骨，避开下牙槽神经血管柬和恒牙胚，术中安置稳妥牵引器后，即刻开始牵引延长2～4mm，术后3—5d即开始牵引延长，每天延长1—2mm，直到完成模拟设计的预期下颌升支延长效果。术后对7例患者进行随访，复查CT，进行三维重建，测量健、患侧下颌升支长度，并对术前和术后各测量数据进行比较。结果7例患者术后均快速牵引，下颌骨延长7～20mm，平均14．6mm，术后患者面部垂直方向的对称性得到较大程度的改善，骀平面较术前趋于水平，未发生神经及牙胚损伤等并发症。术后随访17～32个月，平均22个月，外观及咬合功能基本正常，术后患侧下颌升支长度比术前明显增加。结论应用下颌升支矢状劈开截骨行牵引成骨术，能加快牵引速率，缩短疗程，可保证牵引完成后下颌升支宽度能保持甚至增宽，厚度有所增加，并发症少，能有效矫治半侧颜面短小畸形的颌骨不对称。

Objective To investigate the effect of sagittal split ramus osteotomy（SSRO） combined with distraction osteogenesis（DO） for hemifacial microsomia （HFM）. Methods From January 2013 to September 2015, 7 cases of unilateral HFM were included in the study. The 3-dimensional reconstruction images were used for the operation design. The location of the germs and inferior alveolar nerve was marked to avoid injury. The distractor was fixed after SSRO. The distractor was distracted 2 - 4 mm intraoperatively and began enlongation 3 -5 days after operation, 1 -2 mm every day until the pre-designed length attained. The patients were followed up for 3-D CT and measurement of the height of bilateral ramus. Results The enlongation length was 7 mm to 20 mm （mean, 14. 6 mm）. The facial symmetry and occlusion plane was improved a lot. No complication occurred. The mean follow-up period was 22 months （range 17 -32 months） with almost symmetrical appearance and occlusion function. Conclusions SSRO combined with DO has a good therapeutic effect and low complication for patients with HFM. The distraction rate is relatively high with a short treatment period. The ramus width, even thickness, are not decreased, or even can be increased after DO.