Treatment of Bisphosphonate-related Osteonecrosis of Jaw (BRONJ) in Rabbit Model: A Proof-of-concept Animal Study Comparing Angiogenesis Factor Versus Autologous Bone Marrow-derived Osteoblasts (ABMDO)

Objective: We created Bisphosphonate-related Osteonecrosis of Jaw (BRONJ) in rabbits and treated them with an angiogenesis factor or autologous bone marrow derived osteoblasts (ABMDO) to assess the efficacy of the treatment by Micro-computerized Tomography (M-CT) and histopathology. Material and Methods: Thirty female New Zealand rabbits were procured and were divided into three groups of 10 animals each. The number of animals to achieve statistical significance was based on the reported studies. Group I was control group (C), Group II was Osteoblast group (O), and Group III was angiogenesis group (P). In all Groups, BRONJ was produced. At 8 weeks of tooth extraction, BRONJ was confirmed histologically and radiologically in two rabbits from each group of animals. Group I received 0.5 of normal saline, Group II received a single dose of 5 million osteoblasts suspended in 0.5 ml, and Group III received 5 mg of angiogenesis factor thrice weekly for three weeks. The healing of BRONJ was assessed using M-CT and histopathology. Results: In O and P groups, the extraction sockets healed and closed with normal-looking tissue, whereas in the C (control) group, suppuration with an area of necrosis was observed. Micro-CT analysis of socket revealed an exaggeration on non-mineralized soft tissue volume in the C group, whereas most of the bone promotion parameters were improved in the O and P groups with statistical difference (P<0.001) for the parameters bone volume, bone surface area, trabecular number and trabecular thickness. Histologically, the element of healing was represented by reactive bone formation and fibrosis, which were more prominent in groups O and P as compared to the control group. Conclusion: Our study shows that ABMDO and angiogenesis factor have a robust potential to heal BRONJ. Clinical Relevance: The study shows angiogenesis factor and osteoblasts heals BRONJ and warrant sincere human trials to tackle this unrelenting complication of bisphosphonates use.