中国研究：颏成形复位术之骨再生与软组织反应

北京协和医学院数位学者联合回顾性分析了2009-2013年间接受颏成形复位术（reduction gonioplasty）的59位患者，随访期为12个月，该方法可使下面部更尖，同时产生丰满的脸颊，使人显得年轻，是一种有效且可预测的下面部塑形术。

• 使用文中手术方法，骨再生不会引起面部宽度增加；

• 在无冷却水的情况下，使用高速旋切钻可减少骨再生；

• 下颌前部软组织反应率更高，这表明无软组织下垂；

• 下颌角间线以下（L4、L5）减少的软组织宽度以及软组织反应率超过100%；

• 颏成形复位术对于正面观下颌骨下边缘低的患者，缩小面部宽度更有效，能够实现更大的面部下边缘角度变化；

• 该研究数据能够实现更精确的术前模拟，但数据也表明软组织反应率有较大标准差，这可能是由于年龄、脸型、骨量减少、体重变化、皮肤纹理、脂肪组织比例以及咬肌等存在差异。

全景X光下术前设计（OP：咬合面；Go’：术后新下颌角点；A：下颌骨下边界上的截骨线末端；A’：延长的骨切除术线末端）

头影测量分析（L1-4位于高速旋切钻截骨区；L5位于往复锯截骨区）

下颌宽度变化

软组织宽度变化

软组织反应率（白箭头：软组织反应最低的区域；较低位的线软组织反应率更高，即L5 > 4 > 3；灰色箭头：L1和2上软组织宽度显著减低）

软组织宽度和面部下缘角（α：面部下缘与水平线间的锐角）

手术方法：

A preoperative panoramic radiograph was used to design a safe and optimal osteotomy line. All patients underwent general anesthesia by nasotracheal intubation. The intraoral incision extended from the anterior ramus of the mandible to the second premolar, 5 mm from the buccal cavity groove. The periosteum was raised to expose ramus below the occlusal plane, angle, and body posterior to mental foramen. First, the outer cortex was burred using a large grinding ball first. Then, the curved osteotomy line was marked with a small high-speed rotary grinding ball from the newly established gonial point (Go'), which was usually located on the level of the occlusal plane, to the inferior rim of the mandible under the second premolar. The mandible was then penetrated with the grinding ball. Then, the ostectomy line was elongated to the anterior mandible with reciprocating saw to achieve a sharper chin, and the outer cortex of the anterior mandible was burred with the grinding ball. The incision was closed with 1-0 silk suture after thorough irrigation of the operation cavity. A drainage syringe was placed for vacuum drainage on both sides for 24 hours. Finally, the mandibular area was compressed with pressure dressing for 3 to 5 days.