ABSTRACT
<p><b>OBJECTIVE</b>To investigate the treatment effect of mandibular osteoradionecrosis (ORN) by autologous bone marrow mesenchymal stem cells (BMMSC) in miniature pigs.</p><p><b>METHODS</b>Six miniature pigs with mandibular ORN (25 Gy) were used. BMMSC were separated and cultured in vitro and then implanted on to the premolded hydroxyapatite-tricalcium phosphate (HA-TCP). The BMMSC-HA-TCP complexes were implanted into the defective area of mandibular ORN in 4 animals. Implantation of only HA-TCP in 2 animals served as control. Gross observation, spiral CT, coronary CT and histopathologic examination were carried out.</p><p><b>RESULTS</b>Fistula disappeared in animals with BMMSC-HA-TCP complexes 3 months after implantation, while fistula was found in controls. Spiral CT analysis showed that cortical bone repair were found 4 months after BMMSC-HA-TCP complexes implantation, while bone damage (cortical and cancellous bone fracture) increased in controls. Histopathologic examination revealed that 4 months later after BMMSC-HA-TCP complexes implantation, new bone formation and bone cells could be observed, but there was a large number of fibrous tissue and no new bone in controls.</p><p><b>CONCLUSIONS</b>Transplantation of autologous BMMSC with HA-TCP may have therapeutic effect in the treatment of mandibular ORN.</p>