Background: Mandibular distraction is a well-established method of correcting facial asymmetry in hemifacial microsomia. However, asymmetry in lower facial width remains after distraction because of its inability to increase bone thickness. Therefore, the authors used mandibular outer cortex bone grafting to augment the lower face following distraction to restore facial symmetry.
Methods: From January of 1997 to December of 2007, 21 patients with hemifacial microsomia underwent unilateral mandibular distraction followed by mandibular augmentation using mandibular outer cortex bone graft harvested from the normal side. Age at surgery ranged from 7 to 27 years. Facial symmetry was evaluated based on medical photography and radiography with a minimum 6-month follow-up.
Results: Mandibular height and length were expanded successfully with distraction, resulting in improvements in chin position and oral commissure level. Lower facial width was increased on the affected side and reduced on the normal side after bone grafting. Thus, three-dimensional facial symmetry was significantly improved in all patients. Long-term follow-up showed no evidence of relapse. The majority of the patients were satisfied with the reconstructive outcome.
Conclusion: Mandibular augmentation with bone grafts harvested from the contralateral outer cortex effectively addressed the asymmetry in lower facial width that was uncorrected by distraction alone, achieving three-dimensional restoration of facial symmetry in hemifacial microsomia.