Mandibular grinding osteotomy is a plastic surgery that measures the position close to the mandibular angle in the mouth, removes all the inner and outer layers of the redundant mandible, and then continuously grinds and thins the edge of the external plate of the redundant mandible. In plastic surgery, the facial skin and muscles are opened from the mouth, the muscles are separated from the periosteum, and the bones that need to be polished are exposed. Draw the osteotomy line according to the designed bone cutting amount. Finally, according to the osteotomy line, the mandibular angle was removed with a long-handled swing saw. Generally, it is 3~4 cm long and 1~2 cm high, which can be cut into an arc shape, and the edges and corners after osteotomy can be smoothed. Achieve the effect of face-lifting.