Ten-year follow-up of a patient with hemifacial microsomia treated with distraction osteogenesis and orthodontics: An implant analysis

Introduction: Distraction osteogenesis (DO) has become an accepted treatment method for patients requiring mandibular lengthening because of congenital malformations. However, the skeletal growth pattern of a distracted mandible in the long term has still not been clearly shown in the literature. The purpose of this report was to analyze the dentofacial changes observed during a 10-year follow-up period in a patient treated with mandibular DO. Methods: The patient was a 12-year-old girl with hemifacial microsomia who had undergone DO with an external device. Morphologic changes during the observation period were evaluated on panoramic radiographs and posteroanterior and lateral cephalograms. Six Bjork-type titanium implants were placed bilaterally in the mandible under local anesthesia to analyze the mandibular skeletal changes over time. Results: Marked lengthening was achieved during the active phase of mandibular distraction. The ratio between the ramus heights of the affected and normal sides improved significantly in the affected side's favor as the mandible was lengthened, but this ratio returned to its initial value after 10 years. Conclusions: Although there was some growth on the affected side during the follow-up period, it was not enough to catch up with the growth on the normal side. The original asymmetry recurred as a consequence of the growth pattern in this patient with hemifacial microsomia.