Animal models of elastic distraction osteogenesis for reconstruction of mandibular segmental defect

Objective: To establish suitable animal models for elastic distraction osteogenesis using titanium-nickelalloy distractor for reconstruction of mandibular segmental defect. Methods: Eight adult hybrid canines and twelve adult New Zealand rabbits were used in the experiment. Segmental defects were created by surgical osteotomy, 3cm in canine mandibular body and 1.5cm in rabbit mandibular ramus respectively. Titanium-nickel distractors, designed by us, were settled in different ways and bone transport distraction was applied. The animals were observed periodically and sacrificed 3 months after the operation. Mandibles were harvested to observe reconstruction results of the defect. Results: Under elastic distraction forces of titanium-nickel distractor, the transport bone disc created by osteotomy and connected by lingual periosteum attachment could move automatically to implement distraction osteogenesis. The segmental defects were preliminary reconstructed. Conclusions: Automatic distraction osteogenesis by elastic loading could be a hopeful and useful technique. The canine and rabbit are suitable animals for further research of the technique.