Dental stability and radiographic healing patterns after mandibular symphysis widening with distraction osteogenesis

Distraction osteogenesis is the biological process of new bone formation between bone segments that are gradually separated by incremental traction. The purpose of this study was to assess dental stability and radiographic healing patterns following mandibular symphysis widening with distraction osteogenesis (MSDO) in 19 non-syndromic patients (10 males, 9 females: mean age at the time of surgery 20 years 11 months). To evaluate dental stability, 13 landmarks were measured on the study models of all patients and healing patterns were classified for 11 subjects according to healing times on periapical or occlusal radiographs at three time points: pre-distraction (T1), post-distraction (T2), and follow-up (T3; average 1 year 6 months). Paired t-tests were used to evaluate the change between T2-T1, T3-T2, and T3-T1. The results of this study showed that although there was a decrease in expansion during treatment, the total amount of surgical expansion was maintained. Arch length was significantly increased and irregularity was significantly decreased (both P<0.001). There was evidence of mineralization of the distraction gap in 11 patients within 3 weeks of the end of activation. Radiographically, healing patterns for the distraction gap were diverse, but radiopacity increased over time. MSDO is dentally stable and the distracted gap is mineralized with time, indicating that MSDO is an efficient and stable treatment method in subjects with skeletal mandibular transverse deficiency.