Bimaxillary distraction in hemifacial microsomia: a retrospective study of 6 patients

Abstract

Introduction: Hemifacial Microsomia (HFM) is a congenital condition that induces asymmetric growth in both hard and soft tissues, with the clinical result of mandibular hypoplasia, facial asymmetry, occlusal canting as well as soft tissue hypoplasia. Technique of bimaxillary distraction in adults with HFM had been introduced by Monasterio FO since 1997. Since 1999, a protocol of bimaxillary distraction was employed in patients. Objective: To retrospectively assess the long-term effect of bimaxillary distraction in terms of hard and soft tissue stability. Material and Methods: Patients presented with HFM treated with bimaxillary distraction were recruited in this study. Patients’ folders were studied. Clinical photos and radiographs taken preop, after activation of distractor, 6-month, 1-year and 2-year after operation were selected for assessment of change in soft tissue profile in hard tissue based on occlusal canting measurement. Results: Six patients (2×Type 1, 2×Type 2a and 2×Type 2b) were recruited in this study. The mean age is 15.8. The mean preop occlusal (plane) cant is 8.17º. The mean total activation is 20.5 mm, with a mean of 1.67º of overcorrection acheived. Relapse was noticed since 6-month following distraction. On 2-year following distraction, patients presented with −0.4ºof occlusal cant. The mean relapse was 2.2º. Soft tissue augmentation, in terms of Medpore or scapular flap, is required in all of the patient. Conclusions: Bimaxillary distraction is an effective procedure for treatment of HFM with severe occlusal canting. Overcorrection is reccommended during activation.