Osteotomy: The incision starts from the upper and outer side of the occlusal plane at the front edge of mandibular ramus, and goes 5mm along the buccal side of vestibular sulcus to the first bicuspid of mandible, so as to cut the mucosal periosteum. The subperiosteal separation technique was used to expose the middle and lower segment of mandibular branch, mandibular angle and the posterior part of mandibular body.
Grinding: also known as bone grinding, the incision design and periosteum peeling are the same as before. Grind the lower side of mandible with a grinding head to make it wedge-shaped. Therefore, the effect of surgery is quite different from the former method, and the appearance and touch of the former method have changed obviously. However, this method may still feel an obvious square mandible after operation, but there is no such symptom in appearance, so the operation effect is obvious and it is popular at present!