1. There are incisions and scars after operation. This is because the amount of bone removal in mandibular angle plastic surgery is also large, but the incision is exposed, which is easy to cause the scar of mandibular angle plastic sequelae. 2. Nerve injury, the sequela of mandibular angle resection may damage the mandibular marginal branch of facial nerve, leading to paralysis of the upper and middle part of platysma, descending oral muscle and descending labial muscle, facial deformation (especially when smiling and other facial expressions) and asymmetry. 3. Cause facial paralysis or local facial paralysis. Because mandibular angle plastic surgery may cause facial artery, external carotid artery and inferior alveolar artery damage through trunk or branch, resulting in massive bleeding.