Bimaxillary advancement is a common orthognathic surgical technique used in oral and maxillofacial surgery, mainly for retrusion of the upper and lower jaws, and has been applied by the Stanford Sleep Center to treat patients with severe obstructive sleep apnea hypopnea syndrome (OSAHS) who have failed phase I surgery, achieving a success rate of nearly 98 The success rate was nearly 98%. From January 2005 to April 2009, a total of 10 patients underwent bimaxillary advancement, of which 6 patients were followed up for more than 6 months, and the efficiency rate was 100% according to the criteria of OSAHS Xiamen Conference, with 5 cases of significant effect and 1 case of effective effect. Data and methods 1.1 Clinical data From January 2005 to April 2009, a total of 10 patients with OSAHS underwent bimaxillary advancement, including one patient who underwent bimaxillary advancement after failure of external UPPP, two patients who underwent bimaxillary advancement in phase I and HUPPP in phase II, three patients who underwent both bimaxillary advancement and HUPPP, and four patients who underwent bimaxillary advancement alone. seven patients underwent prophylactic tracheotomy. Seven patients underwent prophylactic tracheotomy. All patients met the following surgical inclusion criteria: ① snoring during sleep with symptoms of breath-holding, daytime drowsiness, memory loss, etc. Multi-channel sleep monitoring showed predominantly obstructive sleep apnea with apnea hypoventilation index >20 breaths/h; ② specialist examination showed tonsillar size division of 1 to 2 degrees, tongue height division of 3 to 4 degrees, and normal epiglottis morphology under indirect laryngoscopy; ③ jaw dysplasia (SNB <75°,PAS＜11 mm) ④ Refusal or intolerance of CPAP (patients did not accept or received CPAP treatment for less than 5 d per week or less than 4 h per day after the doctor's recommendation); ⑤ Good health status to tolerate surgery; ⑥ Strong desire for surgery. 1.2 Preoperative preparation: including oral examination, dental cleaning, X-ray cephalometric analysis, orthognathic surgery preoperative shape prediction analysis, model surgery and occlusal guide fabrication. Generally, intermediate occlusal positioning plates of about 5 mm, 7 mm and 10 mm were made according to the pre-operative orthognathic prediction analysis. Splinting of the maxillary and mandibular arches was performed one day before surgery or after anesthesia. All patients were treated with CPAP for 5-7 days before surgery. 1.3 Surgical approach: The maxillofacial and oral cavity were disinfected, the bilateral tonsils were removed with radiofrequency assistance, osteotomy was performed according to the Lefort I osteotomy line, the medial wall of the maxillary sinus on both sides was chiseled, the lateral wall, the pterygomaxillary junction, and finally the nasal septum was chiseled and the maxilla was folded down. Then, the maxilla was moved forward, the median plate was put in place, the intermaxillary ligatures were made, and both sides were fixed with 2 L-shaped titanium plates. The ascending mandibles were split sagittally bilaterally, and the mandibles were moved forward to restore the patient's preoperative occlusal relationship or in place with a terminal guide plate, intermaxillary ligatures, and a 6-hole titanium plate was fixed on each side. A "convex" osteotomy was made in the middle of the chin, and the osteotomy block was moved forward 8-10 mm and fixed with a Z-shaped titanium plate, and the wound was rinsed to stop bleeding and sutured. Postoperative ICU monitoring for 1-3 days, antibiotics were routinely given for 5-7 days to prevent infection, oral irrigation twice a day, and intermaxillary traction for 1 month. PSG was rechecked 6 months after surgery. 1.4 Efficacy assessment criteria: all patients were followed up for more than 6 months, and the treatment effect was judged according to the efficacy assessment basis of the 2008 Xiamen meeting [2]. Cured: AHI <5 times/h; efficacious: AHI <20 times/h and reduction ≥50%; effective: AHI reduction ≥50%; ineffective: AHI reduction <50%. Results All patients completed the surgery successfully, 3 patients underwent simultaneous uvulopalatopharyngoplasty and 7 patients underwent prophylactic tracheotomy. The operation time was 3.5-5 hours, the average intraoperative bleeding was about 400 ml, and no serious complications such as respiratory distress, hemorrhage and accidental mandibular fracture occurred in any of the patients during the perioperative period. 6 patients had their PSG rechecked 6 months after the operation, and according to the efficacy assessment of Xiamen Conference, 5 cases were effective, 1 case was effective, 83% were effective and 100% were efficient. After the operation, the snoring loudness and ESS were significantly improved compared with the preoperative ones, from the average of 8.4 and 16.7 points to 2.0 and 5.2 points respectively. oxyhemoglobin saturation below 90% (CT90) improved from 70.5% and 22.23% preoperatively to 84.17% and 3.31%, respectively. The sleep architecture also improved more significantly, as evidenced by an increase in deep sleep time from 6.7% to 15.2%. Discussion Orthognathic surgery for the treatment of obstructive apnea hypoventilation syndrome was first reported by Kuo [3] in 1979. The principle of orthognathic surgery is to increase the volume of the nasopharynx, palatopharynx, lingual pharynx and oral cavity by moving the soft palate, hard palate, chin-lingual muscles and tongue root forward behind the upper and lower jaws, and to increase the muscle tone of the chin-lingual muscles to ultimately increase the caliber of the upper airway and relieve obstruction. The operation is difficult and the treatment process is complicated. If the preoperative occlusal relationship is disturbed, preoperative and postoperative orthodontic treatment and maintenance of the occlusal relationship should be performed by the orthodontic department. In order to ensure the accuracy of intraoperative jaw advancement and surgical results, preoperative measurement and analysis of facial structure, simulated surgery and result prediction are required. Based on the simulated surgery, an occlusal guide is made to locate the intraoperative jaw advancement distance through plaster model surgery. Therefore, theoretical knowledge of oral and maxillofacial surgery and good training in oral and maxillofacial surgery as well as close cooperation with orthodontics are necessary to perform this technique. The main purpose of orthognathic surgery in oral and maxillofacial surgery is to correct congenital or acquired maxillofacial deformities, to restore or reconstruct the normal appearance of the patient, and to obtain improvement of the occlusal relationship and airway at the same time on the basis of improving the appearance, and it should be said that the main purpose of this type of patients is to improve the appearance as the first purpose. For some patients with OSAHS with jaw dysplasia, the primary goal of orthognathic surgery is to enlarge the airway and improve the appearance on the basis of enlarging the airway as much as possible. Therefore, the preoperative design of these patients should be designed to advance the jaw as far as possible under the condition of acceptable cosmetic changes, and it is not necessary to design the advancement distance exactly according to the requirements of normal cosmetic appearance. In fact, this group of patients is also the best indication for bimaxillary advancement, and almost all patients are very satisfied with the postoperative cosmetic changes. In addition, for OSAHS without obvious jaw dysplasia, if lingual-pharyngeal obstruction is present in the preoperative examination, the patient has a strong desire for surgery, is financially capable, and does not care about the slight change in appearance, bimaxillary advancement can also be considered. Bimaxillary advancement is currently the only procedure comparable to CPAP treatment.Riley et al [1] reported 306 patients with OSAHS, of which 91 patients with failed stage I surgery underwent stage II surgery (MMA) and 89 achieved success with a success rate of 98%. The six patients in our group who were followed up for more than 6 months also achieved any satisfactory results. According to the AHI less than 20 and reduction of 50% or more as significant effect, 5 patients obtained significant effect, and the patient's significant rate was 83%. The data suggest that bimaxillary advancement is currently the most effective treatment for OSAHS in surgery. For patients with OSAHS who strongly desire a surgical cure with jaw dysplasia, bimaxillary advancement is the best option.