Growth patterns and intraoral distraction osteogenesis: craniofacial microsomia versus temporomandibular joint ankylosis

Intraoral distraction osteogenesis (DO) is a mainstay for the treatment of mandibular hypoplasia. Aim of this study was to assess the long-term stability and compare the patterns of growth unilateral intraoral mandibular distraction in two groups of patients: one affected by hemifacial microsomia HFM and the other after removal of TMJ ankylosis. Seven patients with HFM and 6 patients who had previously undergone removal of TMJ ankylosis were included in the study. Records included photographic data cast models. postero-anterior (PA) and panoramic x-rays taken preoperatively, at the end of distraction and after a mean follow-up of 5.6 years. Mandibular distraction had an immediate effective role in the growth of the mandible in both groups, but in the follow-up, the comparative analysis of the two groups of patients revealed that in patients with TMJ ankylosis the rate of mandibular growth remained stable over time in the growing age, whereas in patients with HEM a slight asymmetry would progressively show on the distracted side during growth.