Extensive Mandibular Distraction : A Retrospective Analysis

Purpose: The aim of this retrospective study was to evaluate long-term results regarding skeletal stability and Neurosensory Disturbance (NSD) in the Inferior Alveolar Nerve (IAN) after mandibular advancement by distraction osteogenesis using an intraoral device in an adult cohort. Patients and Methods: Twenty adult patients (13 women and 7 men; mean age 41 years) were included. Mean mandibular advancement was 11.1 mm (range 6 mm to 15 mm); 19 of the 20 patients had a mandibular advancement >7 mm. The skeletal stability was analyzed with cephalometric analysis using lateral cephalograms at predistraction (T0), start of consolidation (T1), and postdistraction after device removal (T2). The basal sagittal relation of the mandible in relation to the cranial base (SNB), the relation between the maxilla and mandible (ANB), and the mandibular jaw angle (GN-tgo-Ar) were analyzed. Results: Cephalometric analysis indicated significant differences in ANB, SNB, and mandibular jaw angle between T0 and T1. There was also a significant difference in the mandibular jaw angle between T1 and T2. Sensory function in the mental nerve was subjected to evaluation. Forty percent of the operated sides had a partially affected sensory function at the 18-month postdistraction follow-up. Six patients (30%) had complications registered between the osteotomy and removal of the distraction device; two had device-related problems, two had operator-related problems, and two patients had minor problems with infection and local irritation. Conclusion: Mandibular distraction osteogenesis is a sagittal skeletally stable method for adult patients in situations with larger advancements, with no risk for total loss of sensory function