First, some common risks are asymmetry. Mandibular angle surgery cannot guarantee complete symmetry, because everyone's situation is different. Some people may have different mandibular angles on both sides, and some people may have this situation because of cervical vertebra deviation. So we will communicate with patients before operation to find out the reasons for this asymmetry. Surgery can't be absolutely symmetrical, but it can be relatively symmetrical with the naked eye. The other is bleeding, because the medullary cavity, masseter muscle and posterior facial vein ooze. With the continuous development of technology in recent years, there are fewer and fewer cases of massive bleeding and even life-threatening in clinic. Another is a fracture. If the osteotomy line does not follow our previous design, there may be fractures that do not require osteotomy, and the common one is condylar fracture. Once this happens, it may affect the occlusal function of patients to some extent. In this case, external fixation is needed, and the nail plate may be used as an auxiliary treatment for about a year. The other is nerve damage. Nerve injury mainly includes two types. One is the sensory nerve. After the inferior alveolar nerve and blood vessels are injured during the operation, the lower lip may be numb, but some, such as long arc osteotomy, have no nerve injury, but the nerve canal may be pulled during the operation, resulting in this transient edema. In this case, the patient need not worry, because the edema is reversible. Generally, this feeling can gradually recover from 3 months to half a year after operation. Another kind of nerve injury is motor nerve injury, mainly the mandibular marginal branch of facial nerve. After this happens, the patient's mouth is mainly skewed, which is also rare in clinic. Therefore, in general, mandibular angle surgery is a big operation compared with other operations, which has certain risks, but as long as you choose a regular hospital and a doctor with this technology, the incidence of such complications can be greatly reduced.