Therapeutic effect of anterior subapical osteotomy combined with postoperative orthodontic treatment for bimaxillary protrusion based on surgery-first approach

Objective To invesigate the therapeutic effect of anterior subapical osteotomy combined with postoperative orthodontic treatment for bimaxillary protrusion based on surgery-first approach(SFA). Methods From April 2015 to April 2016, 22 adult patients with bimaxillary protrusion were treated with bimaxillary anterior subapical osteotomy without peroperative orthodontic treatment. Digital computer-aided technology was used for preoperative design and dental model simulation surgery. Then the occlusal guide plate was made for intraoperative built-up of temporary occlusion. Two weeks after orthognathic surgery, a short-term orthodontic treatment was carried out to improve the occlusion. Cephalometric analysis was done to evaluate the treatment effects. 19 cephalometric parameters about hard and soft tissues were measured and compared in all cases before and after SFA combined treatments. All data were statistically analyzed by SPSS software package. Results Primary healing was achieved in all the 22 cases without any infection or necrosis of bone and dental pulp. During the follow-up period of 6-12 months, all the patients were satisfied with the profile contour. The cephalometric parameters of hard and soft tissues changed remarkably. U1E-McN and L1E-McN set back (-10.5±4.9) mm and (-8.0± 6.9) mm respectively. Upper and lower lip set back obviously. SNA decreased from (82.5±2.8) to (77.9±2.3) degrees on average. SNB decreased from (79.1±5.4) to (74.6±3.8) degrees on average. Upper and lower lip protrusion decreased obviously. TUL-E line decreased from the mean value of (2.7±2.7) mm to (0.5±3.2) mm and TLL-E line from (5.2±4.0) mm to (1.4±2.7) mm. The aesthetic contours were remarkably improved. Conclusions Anterior subapical osteotomy combined with postoperative orthodontic treatment based on SFA could correct adult bimaxillary protrusion effectively with normal occlusion, satisfactory soft tissue aesthetic profile. Key words: Subapical osteotomy; Surgical orthodontics; Bimaxillary protrusion; Cephalometric analysis