正颚手术（Orthognathic surgery）是一种为了修正颚部及脸部的构造及发育问题或改善睡眠中止症（sleep apnea）、颞颚关节功能障碍（TMJ disorders）、骨骼问题导致之咬合不正或其他不易以牙齿矫正器完成的齿列矫正问题所施行的手术；这项手术通常也会用以治疗先天的唇颚裂。正颚手术的做法需要把骨头切开再以骨板及骨钉接合，而像是垫下巴手术（chin augmentation）这种需要增大或缩小的整型，也能顺便在主要的手术施作过程中由同一位外科医师在同时间完成。

Orthognathic surgery /ˌɔːrθəɡˈnæθᵻk/ is surgery to correct conditions of the jaw and face related to structure, growth, sleep apnea, TMJ disorders, malocclusion problems owing to skeletal disharmonies, or other orthodontic problems that cannot be easily treated with braces. Originally coined by Harold Hargis, it is also used in treatment of congenital conditions like cleft palate. Bones can be cut and re-aligned, then held in place with either screws or plates. Orthognathic surgery can also be referred to as corrective jaw surgery.