3.The two most commonly used surgical techniques to setback a prognathic mandible include the bilateral sagittal split osteotomy and the vertical ramus osteotomy.

• 二种最普遍使用正颚手术方法来改善下颚骨前突症的方法是双侧矢向面骨切开术及垂直下颚枝骨切开术。