The current gold standard for mandible reconstruction is with autologous bone, either as an osseous free flap or a nonvascular bone graft. The success of such grafts is entirely dependent upon the vascularity of the recipient site. The grafts are eventually replaced by ingrowth of bone from the recipient site through osteoconduction.

This presentation describes the reconstruction of a 12-cm mandibular defect after the resection of an ossifying fibroma using in situ osteogenesis (ISO) with an implant composed of recombinant human bone morphogenetic protein (rhBMP-2) and activated collagen sponge (ACS). Osteoinduction with rhBMP-2 occurs independent of recipient site blood supply by stimulating vascular ingrowth and attracting the surrounding living cells into the implant. The resulting membranous bone was histologically identical with that of the original bone. After 24-weeks of consolidation, the regenerate bone was able to be osteotomized and distracted successfully to achieve the desired mandible height.

The resultant savings in time, the elimination of donor site morbidity, and the avoidance of microvascular technical issues make ISO an attractive means for reconstructing the human mandible and other membranous bones of the maxillofacial skeleton.