② Accidental bleeding during operation and hematoma formation after operation. Mandibular angle osteotomy's careless injury to well-known blood vessels can lead to accidental bleeding. The position of incision in oral mucosa is too high, which may cut off buccal artery and vein. At this time, ligation or electrocoagulation should be used to stop bleeding. If the position of the osteotomy line is too high, the inferior alveolar nerve and vascular bundle in the mandibular canal will be damaged during osteotomy, which will cause serious bleeding. Therefore, when designing the osteotomy line, we should pay attention to avoiding the mandibular canal and not cutting off too many mandibular angles. The operation in this area should be performed under the periosteum.
③ The therapeutic effect is not ideal. Some patients not only have overgrowth of mandibular angle and hypertrophy of masseter muscle, resulting in too wide lower face and too wide upper face. It is impossible to achieve the ideal therapeutic effect simply by mandibular angle plasty. Therefore, it is necessary to analyze and evaluate the patient's face comprehensively before operation, and tell the patient the problems existing in the operation and the possible effects of the operation realistically. Swing saw osteotomy of mandibular angle is convenient and quick, but it is difficult to accurately osteotomy according to the designed osteotomy line and range. The common problem is to cut off the mandibular angle in a straight line. At this point, the angular protrusions at both ends of the osteotomy section must be polished and corrected. If necessary, a second osteotomy can be performed.
④ The facial nerve and parotid duct were damaged. Oral mandibular angle plasty is not easy to damage the facial nerve, but the buccal branch and mandibular marginal branch of the facial nerve may be damaged when the masseter muscle is separated too shallowly or the external masseter muscle is removed by mistake. The parotid duct may be damaged if the position of masseter muscle separation and resection is too high and too shallow. Therefore, it is only necessary to remove the internal masseter muscle during the operation, and the scope of muscle removal is limited to the lower half of the mandibular branch, so as not to hurt the facial nerve and parotid duct.
⑤ Oral injury and surrounding soft tissue injury, the visual field is limited during oral surgery, and sometimes excessive stretching of soft tissue in order to fully expose the osteotomy site can cause oral strain. Applying a small amount of chlortetracycline eye ointment around the lips can effectively prevent and alleviate this complication.
⑥ Wound infection, the incidence of infection after mandibular angle plasty is not high, unless there is obvious hematoma after operation, so preventing wound bleeding is the key measure to prevent infection.