In mandibular plastic surgery, the mandibular angle can be improved by removing the outer plate. The bone grinding operation is less harmful and safe, and the high osteotomy of mandibular angle can obviously reduce the face. Mandibular angle grinding is the mainstream mandibular plastic surgery method for facial reconstruction at present. Mandibular angle grinding adopts local anesthesia, and the mandible is ground through a 3cm incision in the mouth. Because of the clear vision, there is little bleeding. Will not damage facial nerves, and the polished surface is smooth.