Management of acquired open bite associated with temporomandibular joint osteoarthritis using miniscrew anchorage

This article reports the orthodontic treatment of a patient with skeletal mandibular retrusion and an anterior open bite due to temporomandibular joint osteoarthritis (TMJ-OA) using miniscrew anchorage. A 46-year-old woman had a Class II malocclusion with a retropositioned mandible. Her overjet and overbite were 7.0 mm and -1.6 mm, respectively. She had limited mouth opening, TMJ sounds, and pain. Condylar resorption was observed in both TMJs. Her TMJ pain was reduced by splint therapy, and then orthodontic treatment was initiated. Titanium miniscrews were placed at the posterior maxilla to intrude the molars. After 2 years and 7 months of orthodontic treatment, an acceptable occlusion was achieved without any recurrence of TMJ symptoms. The retropositioned mandible was considerably improved, and the lips showed less tension upon lip closure. The maxillary molars were intruded by 1.5 mm, and the mandible was subsequently rotated counterclockwise. Magnetic resonance imaging of both condyles after treatment showed avascular necrosis-like structures. During a 2-year retention period, an acceptable occlusion was maintained without recurrence of the open bite. In conclusion, correction of open bite and clockwise-rotated mandible through molar intrusion using titanium miniscrews is effective for the management of TMJ-OA with jaw deformity.