Jaw bone becomes smaller can take jaw angle plasty, divided into jaw angle osteotomy and jaw angle outer plate split amputation, suitable for jaw angle hypertrophy, to the lateral and posterior obviously protruding. 1. Mandibular angle osteotomy: clinically, if the mandibular angle osteotomy is taken, generally the first stripping of the operative area, with the head of the oscillating saw, the mandible will be cut and stripped to take out. 2. Mandibular Angle Osteotomy: If mandibular angle osteotomy is performed, it is necessary to split and remove the bone plate from the middle and lower portion of the mandibular branch from the mandibular angle to the outer part of the chin hole. For those who have a prominent mandibular angle with an enlarged biting muscle that leads to a wide face, mandibular angle osteotomy and mandibular angle plate splitting can be performed at the same time.