Longitudinal analysis of mandibular asymmetry in hemifacial microsomia

Reconstruction of the mandible is one of the key elements in the skeletal rehabilitation of patients with hemifacial microsomia. Unfortunately, knowledge about long-term mandibular skeletal growth in these patients is lacking. The purpose of this study was to analyze mandibular skeletal growth longitudinally in unoperated hemifacial microsomia patients from childhood to adolescence. The longitudinal records of 26 patients with unoperated unilateral hemifacial microsomia were utilized. The average age at initial records was 3.1 years, and the average age at final records was 16.7 years. Posteroanterior cephalometric radiographs were utilized to evaluate both horizontal and vertical mandibular asymmetry. Patients also were analyzed according to the grade and side of the mandibular deformity. A paired t test (p < 0.05) and a two-way ANOVA were used to analyze the data. There were 5 patients with grade I, 14 with grade II, and 7 with grade III. The results indicated that the skeletal mandibular asymmetry in hemifacial microsomia is not progressive in nature and that growth of the affected side in these patients parallels that of the nonaffected side. The grade and the side of the mandibular deformity did not influence these findings. These results should be considered when treatment strategies are developed to reconstruct the asymmetrical mandible in hemifacial microsomia.