Effect of mandibular distraction on the temporomandibular joint: Part 2, Clinical study.

Mandibular lengthening by gradual distraction has been gaining popularity. However, the effect of osteodistraction on the temporomandibular joint has been evaluated in patients with craniofacial anomalies who underwent mandibular distraction. Five patients had unilateral expansion and five had bilateral expansion. The mandibles were expanded 1 mm per day until the pogonion was in the midline. Preoperative, immediate, 6-month, and 12-month panoramic and cephalometric radiographs were evaluated. In unilaterally expanded mandibles, the ipsilateral condyle increased in size and volume, became more upright, and was oriented in a more normal vertical axis. The contralateral unexpanded condyle did not show deformational changes. In those mandibles that were bilaterally expanded, both condyles increased in size and volume and became more symmetrical and upright. Osteodistraction appears to affect bone in both local and distant sites. The expanded condyles were stimulated to ensure a more nearly normal shape, size, and configuration.