ABSTRACT
@#Condylar displacement can lead to temporomandibular joint (TMJ) symptoms and relapse after orthognathic surgery. To minimize condylar displacement, numerous condylar positioning techniques have been applied in clinical practice. To verify the effectiveness of condylar positioning techniques in preventing postoperative TMJ symptoms and relapse, we reviewed the literature related to all types of intraoperative condylar positioning techniques in the past 20 years. According to a literature review, positioning techniques aim to seat the condyles at a preoperative position during surgery and are divided into noncomputer-aided and computer-aided condyle positioning methods. At present, computer-aided design/computer-aided manufacturing condylar positioning devices (CAD/CAM CPDs) are the most superior positioning methods and are composed of teeth-supported and bone-supported guidance. The sequence of the remaining technology positioning effect from high to low is as follows: CAD/CAM titanium plate positioning > manual positioning > computer-aided navigation system > image positioning system. Different techniques reach considerable accuracy within 1-2 mm and 1°-2° in locating the preoperative condylar position and preventing TMJ symptoms or disorders and surgical relapse to provide a clinical reference for different levels of surgeons and cases. However, this study lacks randomized controlled trials with large samples and long-term follow-up. Future studies should upgrade the current methods, improve the clinical utility, and develop new positioning techniques.
ABSTRACT
Objective @#To explore the clinical effect of simultaneous distraction osteogenesis of the maxilla and affected mandible combined with second-stage orthognathic surgery for the treatment of adult hemifacial microsomia to provide a reference for clinical practice.@*Methods@#Twelve adult patients with hemifacial microsomia who underwent simultaneous distraction osteogenesis and second-stage orthognathic surgery from 2006 to 2013 were enrolled. Distraction osteogenesis of the maxilla and malformed lateral mandible and second-stage orthognathic surgery were performed according to each patient’s specific conditions. The height ratio of the mandibular ramus of the affected side to the contralateral side, the shift distance of the chin point and the inclination angle of the screw plane were measured before and after the operation, and the therapeutic effect was evaluated with clinical photographs.@*Results @#No patients had obvious complications after the operation, the postoperative aesthetic effect was good, and the relationship between the facial shape and occlusion was significantly improved. The cephalometric measurement showed that the height ratio of the mandibular ramus of the affected side to the contralateral side was increased by 23.83% (t=11.658, P<0.001), the deviation distance of the chin was corrected, and the chin point moved back to the midline by 6.63 mm (t=13.042, P<0.001) on average, and the inclination angle of the occlusal plane was improved and returned to the horizontal plane by 8.83° (t=15.358, P<0.001) on average.@*Conclusion @#The application of simultaneous distraction osteogenesis of the maxilla and mandible combined with secondary orthognathic surgery for the treatment of adult hemifacial microsomia can obtain satisfactory clinical and aesthetic results and has clinical value.