Orthognathic surgery is a relatively well-established procedure and the risk of sequelae is minimal if performed in a regular medical facility. However, since any surgery may have sequelae, the possible sequelae after orthognathic surgery include respiratory tract infarction, osteogenesis imperfecta, hemorrhage, edema, infection and so on. 1. Respiratory tract infarction: after orthognathic surgery, there may be oozing blood and edema of nasal mucosa, which leads to smaller nasal airway, and due to poor drainage of surgical site, hematoma of the floor of the mouth occurs, which leads to respiratory tract infarction due to ventilation obstacle. 2. Bone disjunction: Orthognathic surgery is mainly to adjust the dentition and jawbone, if the intraoperative pressure is not strong enough and the bandage is not in place, it will make the dentition and jawbone trauma healing incomplete, resulting in the symptom of bone disjunction. 3. Bleeding: there will be a lot of bleeding in orthognathic surgery, and the osteotomy surface can not be completely hemostatic, after reset and fixation, it is necessary to rely on the microvascular breaks of the bone section to coagulate on its own, therefore, there will be a small amount of bleeding in the incision and the nasal cavity after the operation. 4. Edema: Orthognathic surgery is more traumatic to the face, so the degree of swelling is heavier. 5. Infection: Orthognathic surgery is done in the mouth, if the oral hygiene is not good after surgery, it will cause infection. It is recommended that patients undergo orthognathic surgery in a regular medical institution. If these symptoms appear, you must consult the doctor in time to avoid affecting your condition.