Principle: Under the condition of local anesthesia or general anesthesia, an angular mandible is sawed off and taken out according to the osteotomy range designed by the original X-ray film, so as to achieve the effect of face-lifting. This kind of operation requires the general anesthesia of the plastic surgeon, who takes a knife from the plastic surgeon's mouth and smoothes the wide mandibular angle. The operation takes one to two hours, and the cosmetic surgeon can leave the hospital within one week after the operation, and can fully recover after one or two months.