Early Distraction for Mild to Moderate Unilateral Craniofacial Microsomia: Long-Term Follow-Up, Outcomes, and Recommendations

Background: There is controversy regarding the treatment of young patients with unilateral craniofacial microsomia and moderate dysmorphism. The relative indication for mandibular distraction in such patients poses several questions: Is it deleterious in the context of craniofacial growth and appearance? This study was designed to address these questions. Methods: A retrospective review of patients undergoing mandibular distraction by a single surgeon between 1989 and 2010 was conducted. Patients with "moderate" unilateral craniofacial microsomia (as defined by Pruzansky type I or IIa mandibles) and follow-up until craniofacial skeletal maturity were included for analysis. Patients were divided into two cohorts: satisfactory and unsatisfactory results based on photographic aesthetic evaluation by independent blinded observers at the initial presentation and at the age of skeletal maturity. Clinical variables were analyzed to detect predictors for satisfactory distraction. Results: Nineteen patients were included for analysis. The average age at distraction was 68.2 months and the average age at follow-up was 19.55 years. Thirteen patients (68.4 percent) had Pruzansky type IIA and six patients (31.6 percent) had Pruzansky type I mandibles. Twelve patients (63.2 percent) had satisfactory outcomes, whereas seven patients (36.8 percent) had unsatisfactory outcomes. Comparing the two cohorts, patients with satisfactory outcomes had distraction at an earlier age (56.4 months versus 89.8 months; p = 0.07) and a greater percentage overcorrection from craniofacial midline (41.7 percent versus 1.8 percent; p = 0.003). Conclusion: Mandibular distraction is successful in patients with mild to moderate dysmorphism, provided that there is a comprehensive clinical program emphasizing adequate mandibular bone stock, proper vector selection, planned overcorrection, and comprehensive orthodontic management.