[Bone mineral density and biomechanical characters of the augmented alveolar ridge by distraction osteogenesis using Ti-Ni shape memory alloy distractor].

Objective To evaluate the quality of the alveolar ridge augmented by Ti-Ni shape memory alloy(Ti-Ni SMA) distractor.Methods All of the mandibular premolars and the first molars were extracted from 12 adult mongrel canines. One month later, box-shaped osteotomy was carried out in the left mandibles and Ti-Ni SMA distractors were imbedded. The right sides served as blank control. The canines were killed 3 or 6 months later and specimens were taken from corresponding area of the experiment sides and the control. Bone mineral density and biomechanical function were measured. Results Bone mineral density, ultimate compressive strength and Young′s Modules of the augmented ridge were lower than the blank control three months after distraction. But the indexes increased and showed no significant difference with the control six months after distraction. Conclusions The canines mandibular posterior alveolar ridge could be augmented by distraction osteogenesis using Ti-Ni SMA distractor, and the new bone is strong enough for implant placement.