A preliminary clinical study of trifocal distraction osteogenesis for reconstruction of segmental mandibular defects

Abstract

Objective To apply internal trifocal distraction osteogenesis in a canine model of mandibular segmental defects and to study the characteristics of regenerating bone in the functional mandible reconstrction.Methods The internal trifocal distractor was used to reconstruct the mandibular segmental defects of 4 canine model. Mandibular segmental defects in the canine models were established and an internal trifocal distractor was implated at the same time. After 8 days of latency period, trifocal DO was started at a rate of 0.5 mm×2 times per day at each distraction region. The regenerating bone was examined by X-ray and histological method during stages of distraction osteogenesis. Distraction was continued for 15 days. At the end of distraction, the distractor was left in place as an internal fixator for 12 weeks.Results The mandibular defect was successful reconstructed for 30 mm in length of 15 days without any complications. The regenerated bone was confirmed based on the presence of new bone deposit along the mandibular defect by the X-ray, histologic examination, immunohistochemical stain, and scanning electron microscope(SEM). Compression osteosynthesis occured at the region of transport disk union. At 12 weeks after the distraction, the entire regenerate bone was showed near normal in and the morphology and in the density.Conclusion Mandibular segmental defect can be reconstructed successfully by trifocal distraction osteogenesis. The whole gap was filled with new bone and the union of two transport disk was occurred at 12 weeks after the distraction.