The Correction of Mild Hemifacial Microsomia: Polyethylene Implantation, Lateral Cortectomy, and Osseous Genioplasty

Han, Kihwan; Cha, Myungkyu

Abstract

Hemifacial microsomia is a condition most frequently associated with facial asymmetry. Authors have experienced eighteen patients with mild hemifacial microsomia who were classified as type IA and IB. For the correction of mandibular asymmetry, mandibular augmentation was performed on the mandibular angle of the affected side using mandibule shaped porous high-density polyethylene(Medpor(R)) in thirteen patients. Reduction mandibuloplasty was performed on the mandibular angle of the normal side using lateral cortectomy in four patients, and genioplasties were used in 2 patients. Osseous genioplasty(n=10), buccal fat removal(n=4), augmentation rhinoplasty(n=2), and onlay bone graft(n=1) as ancillary procedures were simultaneously executed. Except for 4 patients in whom the implants were removed due to exposure and infection, all other patients were satisfied with a more symmetric contour of their face. The results were clinically evaluated through ordinary scale method and photogrammetric analysis. The mean score was rated 'good' as 12.5 points, and the mean bigonial distance index and the mean gonion-midsagittal distance index were 105.20%(p=0.035) and 100.65%(p=0.368), respectively, which meant a more symmetry of the lower face. In minor asymmetry of the mandible in cases of hemifacial microsomia, augmentation with cautions of the affected side, reduction with lateral cortectomy of the mandible in the non-affected side, and an even osseous genioplasty can provide the patient with a more symmetric lower face.