Introduction: Trauma, pathology, and subsequent surgery can result in mandibular defects that may not heal spontaneously, especially when the defect reaches a critical size. Surgeons graft defect areas in order to re-establish continuity, structure, and function. While vascularized free-flap surgery and nonvascularized autogenous bone grafting have been shown to provide excellent outcomes, these methods carry a higher risk of morbidity and mortality due to the need for a separate donor site. Advances in tissue engineering have resulted in the increased use and success of biomaterials, growth factors, and cells that can aid in bone regeneration and potentially replace the need for autogenous bone grafting.
Purpose: The purpose of this study is to compare the effects of poly(lactic-co-glycolic acid) (PLGA), anorganic bovine bone, recombinant bone morphogenetic protein 2 (BMP-2), and nonvascular autogenous bone on bone regeneration efficacy of a critically-sized marginal mandibular defect. We hypothesize that the combined use of an osteoinductive and osteoconductive material will provide a superior environment for bone regeneration.
Materials & Methods: Twenty-eight 4-month-old male Sprague Dawley rats underwent surgical removal of a 5 x 5 x 2 mm section of the mandible along the inferior border. Four rats were placed in each of the following groups: absorbable collagen sponge (ACS), rhBMP-2 + ACS, PLGA, PLGA + rhBMP-2, anorganic bovine bone, anorganic bovine bone + rhBMP-2, or autogenous bone. The rats were sacrificed at 8 weeks following the surgical procedures. µCT and H&E analysis were subsequently performed.
•Using a combination of an osteoconductive and osteoinductive material, such as anorganic bovine bone and rh-BMP2 respectively, can serve as a viable grafting alternative for treating a critical size marginal mandibular defect
•Anorganic bovine bone and anorganic bovine bone + rhBMP-2 resulted in greater bone volume compared to either PLGA or PLGA + rhBMP-2
Conclusion: The results of this study suggest that the combined use of xenogenic graft materials, particularly the combination of anorganic bovine bone and rhBMP-2, may serve as a viable method for grafting critically-sized mandibular defects. Further studies should focus on evaluating the biomechanical properties of the healing sites when these particular grafting materials are utilized.