Orthognathic surgery is a relatively mature procedure, and as long as you choose a professional surgeon in a regular hospital, there are fewer sequelae. The common after-effects include respiratory tract obstruction, necrosis of teeth and alveolar bone, difficulty in opening the mouth, infection, and so on. 1. Respiratory tract infarction: there may be edema of nasal mucosa and increased secretion after the surgery, which may cause respiratory tract infarction, and you should pay attention to whether there is any reaction of dyspnea after the surgery. 2. Tooth and alveolar bone necrosis: There is a possibility of damage to the inferior alveolar nerve during surgery, leading to tooth and alveolar bone necrosis. 3. Difficulty in opening the mouth: There may be a certain degree of difficulty in opening the mouth after the surgery, so you should avoid opening the mouth widely. 4. Infection: Most surgeries carry the risk of infection. If you have any discomfort after orthognathic surgery, you should go to the hospital in time and take treatment under the doctor’s guidance.