Effects of mandibular setback on the temporomandibular joint: a comparison of oblique and sagittal split ramus osteotomy.
OBJECTIVE
This investigation studied the changes in temporomandibular joint function and condylar position after mandibular setback using different ramus osteotomies.


METHODS
The sample consisted of 50 Chinese adults with mandibular prognathism. Twenty-eight of the patients underwent intraoral oblique ramus osteotomy (IORO), and 22 received sagittal split ramus osteotomy (SSRO) with rigid internal fixation (RIF). TMJ symptoms and radiographic findings were evaluated preoperatively and postoperatively.


RESULTS
After surgery in the IORO group, the TMJ radiographs showed a significant anterior-inferior displacement of the condyle. Seventy-five percent of the preoperatively symptomatic patients reported fewer or no TMJ symptoms and no preoperatively asymptomatic patients developed new TMJ symptoms. In the SSRO group, the TMJ radiographs showed a posterior displacement of the condyle. Sixty percent of the preoperatively symptomatic patients had no improved TMJ function and 8% of asymptomatic patients developed TMJ symptoms after surgery.


CONCLUSIONS
The results of this study show that IORO with MMF appears to be more favorable to the TMJ than the SSRO with RIF; IORO is particularly good in orthognathic surgery patients with preoperative TMJ symptoms.
Hu
J
J
Department of Oral and Maxillofacial Surgery, College of Stomatology, West China University of Medical Sciences, Chengdu, PR China. doctorhu@sc.homeway.com.cn
Wang
D
D
Zou
S
S
D000328:Adult; D005260:Female; D006801:Humans; D019248:Jaw Fixation Techniques; D008297:Male; D008334:Mandible / Q000601:surgery*; D008335:Mandibular Condyle / Q000473:pathology; D019647:Oral Surgical Procedures; D010027:Osteotomy / Q000379:methods*; D011378:Prognathism / Q000150:complications / Q000601:surgery*; D016059:Range of Motion, Articular; D013705:Temporomandibular Joint Disorders / Q000150:complications / Q000503:physiopathology* / Q000601:surgery