Evaluation of Mandibular Symmetry in Patients With Condylar Osteochondroma Who Underwent Intro-Oral Condylar Resection and Simultaneous Bimaxillary Orthognathic Surgery.

Mandibular condylar osteochondroma (OC) can result in facial asymmetry, malocclusion, and temporomandibular joint dysfunction. The authors have previously demonstrated a novel method for conservative condylectomy and simultaneous orthognathic surgery for treatment of mandibular condylar OC. The purpose of this study was to evaluate the immediate improvement and long-term stability of mandibular symmetry in the treatment of condylar OC. Fifty-six patients with unilateral mandibular condylar OC combined with secondary facial asymmetry and malocclusion were enrolled in this retrospective study. The computerized tomography (CT) scans were acquired with the mandible in centric relation (CR) before surgery, 1 week and 12 to 18 months after surgery. The images were reconstructed and processed for the analysis with ProPlan CMF 2.1 software. After defining the skeletal landmarks and the reference planes, the chin deviation, chin rotation and mandibular asymmetry index were calculated. The operations and healing were uneventful and the patients showed no signs of recurrence or temporomandibular joint ankylosis during the follow-up. Facial symmetry was greatly improved right after the surgery in the chin deviation (from 9.2 to 1.7 mm, P < 0.01), chin rotation (from 11.2 to 2.3, P < 0.01) and the asymmetry index of three mandibular landmarks (Go, MF and Sg, all P < 0.01). It also showed a stable result after 12 to 18 months follow-up. We also established a novel measurement method, which showed that the combination of conservative condylectomy via the intraoral approach based on intraoperative navigation and simultaneous orthognathic surgery is effective for improving the facial symmetry when treat the mandibular condylar OC.