A, mandibular angle osteotomy mandibular angle osteotomy must be equipped with miniature bone saw or bone drill osteotomy tools and optical fiber intraoral lighting system. Oral mandibular angle plasty can avoid facial scar, and it is easier to remove part of masseter muscle than external approach, but the surgical field of vision is poor.

Second, the bone plate outside the mandibular angle area was removed. At present, a considerable number of patients do not have obvious overdevelopment of mandibular angle. In this kind of patients, the opening and lateral morphology of mandibular angle are basically normal, but the posterior part of mandible is too wide or the mandibular angle is laterally abduction. If mandibular angle osteotomy is applied to this kind of patients, it will not only destroy the natural lateral curvature of mandibular angle, but also not necessarily achieve the expected correction effect. Excision of lateral cortical bone plate of mandible is an effective method to correct this kind of deformity.

Third, mandibular angle osteotomy's extraoral approach to mandibular angle osteotomy and extraoral approach to partial excision of masseter muscle have the advantages of clear vision, simple operation and easy grasp of bone cutting amount. The disadvantage is that facial scars are left, which may hurt the mandibular marginal branch of facial nerve. At present, mandibular angle osteotomy facial incision is seldom used in clinic.