Definitive surgical correction of the deformity resulting from hemimandibular hyperplasia.

INTRODUCTION: The asymmetric deformity of the mandible resulting from the rare condition of hemimandibular hyperplasia has posed a challenge for aesthetic surgical correction. The literature relating to this condition is reviewed and the results of treatment in a series of patients described.
MATERIAL AND METHODS: A series of treated patients is reviewed and the results of surgery illustrated and discussed. A maxillary Le Fort I osteotomy is first performed where levelling of the occlusal plane is required. The mandibular surgical technique commences with an extended sagittal ramus osteotomy with dissection of the inferior dental neurovascular bundle completely free of the mandible up to and including the mental foramen. The proximal fragment is then rotated cranially leaving undisturbed the soft tissue attachments at the inferior border, with corresponding bone reduction at the upper border. The inferior border of the distal fragment is then reduced to match the new position of the lower border of the proximal fragment, the neurovascular bundle repositioned, and rigid fixation applied. Finally, a straightening genioplasty is performed.
RESULTS: It was possible to overcome the technical and anatomical difficulties associated with correction of this hemimandibular deformity and to achieve a good aesthetic result with acceptable facial symmetry when applying this surgical technique in 3 patients.
CONCLUSION: Hemimandibular hyperplasia can be surgically corrected with good aesthetic and functional results and minimal morbidity.