Abstract: Objective: To build a model of repairing large segmental of mandibular defect using engineering bone with allogenic mandibular scaffold and autologous mesenchymal stem cells. Methods: Twenty-four beagles, weighing 10 to 15 kg, received 30 mm bone surgical defects in each left body of the mandible. The Beagles were divided into 2 groups. The bony defect of the control group (12 beagles) were reconstructed using allograft only. The experimental group (12 beagles) were reconstructed using allogenic mandibular scaffold ioaded autologous mesenchymal stem cells. Beagles from each treatment were sacrificed at 4 weeks, 12 weeks, 24 weeks, or 48 weeks after surgery. Computed tomography were used to evaluate the reconstruction of the defect. Results: Results showed that the experimental group and the control group , allogeneic bone could heal with autologous bone, and could be gradually replaced by autogenous bone. A year later, the allogenic mandibular scaffold of the experimental group were completely replaced by new bone. But the size of the new bone was smaller than original allogenic scaffold. In the control group, the new bone was formed in both ends. The size of the allogenic scaffold wasn't changed compared with original allogenic scaffold. Conclusion: The successful establishment of animal models provides basis for further study the worth and the mechanism of allogeneic bone scaffold combined with autologous bone marrow mesenchymal stem cells to repair segmental mandibular defect.

Key words: Mesenchymal stem cells , Allograft Mandible , Reconstruction , Tissue engineering