Experimental Study Of Mandibular Symphyseal Defects Reconstruction By Trifocal Distraction Osteogenesis

Reconstruction of mandibular symphyseal defects caused by cancerablation surgery or trauma remains a challenge in oral and maxillofacial field. Traditionally bone transportation from the fibula, ilium, scapula or costa, and implants such as metal plates and ceramics has been used in clinic. However the weaknesses of bone graft still exist, it may result in secondary donor site morbidity, and artificial materials retain the characteristics of a foreign body for the host.Since distraction osteogenesis as a technique was firstly applied to lengthen canine mandible in 1973 and used clinically in 1992, it seemed to be a promising new method in craniofacial bone lengthening and reconstruction through the process of bone and soft tissue regeneration under stimulation of gradual tensile stress. However, there have been some problems in using this technique to repair the defects of the mandibular symphyseal, which are in the arched contour. In 1997, Sawaki et al used a distraction device to reconstruct anterior defect of mandible in a patient treated for an oral floor cancer. However, bone graft was inevitable because the bone gap still remained between two transported segments after the completion of distraction. Therefore, in craniofacial bones trifocal distraction osteogenesis needs further investigation.In this experiment, four adult rhesus monkeys were used in this study. The...