Osteotomy with Titanium-Nickel shape memory alloy distracter for repairing mandibular defects in dogs / 中国组织工程研究

ABSTRACT

AIM:Titanium-Nickel shape memory alloy(TiNi-SMA) has memory,abradability and good biocompatibility. It has different osteotomy methods and biomechanics from routine distraction osteogenesis. In this study,the dog models of mandibular defects were established to explore the effect of TiNi-SMA distractor with different osteotomy methods on mandibular distraction osteogenesis. METHODS:The experiment was performed at the animal experimental center of Sun Yat-sen University from October to December 2005. ①Eight male adult Beagle canines of 12-14 kg were selected. A 1.5 cm?1.0 cm bone defect was made in bilateral mandible of each dog. The same size transport bone disc was created mesially by osteotomy on left side and corticotomy on right side. TiNi-SMA distractor was implanted to repair defect. ②One,four,and seven days,and nine weeks after operation,the canines were radiographed for histological analysis and bone formation was observed. RESULTS:Eight dogs were all included in the final analysis. ①Gross observation found the wounds healed well without infection in all experiment dogs. ②X-ray examination showed the bone transport disc on the right side of corticotomy moved to defect area gradually after operation and filled defect area on the whole on the 7th day after operation;The bone transport disc dislocated 1 day after operation and separated from defect area totally on the 7th day after operation on the side of osteotomy(left side). ③ Histological examination demonstrated bone formed in accordance with intramembranous ossification in distraction zone and bony connection between the transport disc and mesial mandible on right side;On the left side,there was a big defect at the area of both distraction and defect zone because of dislocated bone transport disc,and no obvious new bone regeneration was found. CONCLUSION:Corticotomy can be used to establish a successfully canine model of mandibular distraction osteogenesis.