Surgical Orthodontic Treatment Involving Mandibular Premolar Extraction in Patient with Mandibular Retrusion Associated with Temporomandibular Joint Osteoarthritis

Here, we report retention following surgical orthodontic treatment in a patient with vertical maxillary excess associated with temporomandibular joint osteoarthritis (TMJOA) and marked mandibular retrusion. The patient was a man aged 20 years 10 months who presented with the chief complaint of maxillary protrusion. The facial profile was of the convex type due to marked mandibular retrusion. In addition, the patient had a gummy smile. Intraoral findings revealed a Class II molar relation, +11 mm overjet, and 0 mm overbite. Mandibular dentition arch length discrepancy showed crowding of −2 mm, and the maxillary dentition showed a spaced arch of +5 mm. Panoramic radiographs confirmed flattening of the condylar head and proliferation of the bone margin. Cephalometric analysis of the skeletal pattern revealed that, horizontally, the maxilla was anterior and the mandible posterior; vertically, a dolichofacial pattern was noted. The anterior maxillary tooth axis was standard, but the anterior mandibular tooth axis showed labial inclination. Based on these findings, skeletal maxillary protrusion associated with TMJOA was diagnosed. Surgical orthodontic treatment comprised bilateral mandibular first premolar extraction with two-jaw surgery and genioplasty. Orthodontic treatment was performed with a multibracket system using a 0.22-slot pre-adjusted edgewise appliance. At 2 years and 11 months after initiation of treatment, the maxilla was transposed 6 mm upwards by orthognathic surgery and the mandible 17 mm anteriorly and 5 mm upwards by counterclockwise rotation. At 3 years and 10 months, the Pogonion was moved 6 mm anteriorly by genioplasty. At 4 years, orthodontic treatment was concluded on confirming satisfactory occlusion and improvement in facial features. At 2 years after completion of treatment, occlusion and the maxillofacial morphology remain stable, with almost no relapse. In addition, no temporomandibular joint disorder symptoms have occurred. Careful comprehensive follow-up observation will be continued.