Methods The mandible outer cortex were rescted by modified mandible split osteotomy,and mandible angle by oscilating saw,and escess masseteric muscle by scissor.

• 方法:应用口内入路,改良的下颌骨矢状劈开去除外板、摆动锯去除下颌角和咬肌修薄矫正下颌角咬肌肥大,颏部截骨前下移动,取下的下颌骨块充填固定矫正颏部短小。