Mineralization dynamics of regenerate bone during mandibular osteodistraction

Distraction osteogenesis offers an alternative approach for the correction of craniofacial deformities, yet little substantive data is available regar ding mineralization of the forming regenerate. The purpose of this study wa s to evaluate, by plain film radiography and digital subtraction radiograph y, the mineralization dynamics of regenerate bone during osteodistraction. Thirteen skeletally mature male beagle dogs underwent 10 mm of bilateral ma ndibular distraction osteogenesis, at which time the bone was allowed to co nsolidate For either 4, 6, or 8 weeks. The tissues were then evaluated clin ically and radiographically, The results demonstrate that several different types of regenerate are evident during mineralization of the distraction g ap. A classification system is presented based on the length, width, and de nsity of the mineralizing regenerate, as well as the presence or absence of an interzone. It appears that important factors for determining regenerate stability are the presence or absence of an interzone, as well as the widt h of the regenerate relative to the host bone segments. Finally, in cases w here an interzone is present, subtraction radiography may provide a means o f evaluating the level of mineralization within the interzone as well as th e dynamics of mineralization over the course of distraction and consolidati on.