A review of matrix-induced osteogenesis with special reference to its potential use in cranio-facial surgery.

Current data suggests that purified osteoinductive protein packaged into a collagenous delivery vehicle represents a viable alternative to restoring osseous defects with conventional implant materials. The proteins responsible for matrix-induced osteogenesis are the same as those that initiate and complete osseous repair of fractures. Consequently, the process of matrix-induced osteogenesis produced by implantation of the osteoinductive protein mimics the naturally occurring phenomenon of reparative osteogenesis. The collagenous delivery vehicle apparently serves the same role as the inactive collagenous bone matrix which is left after removal of the osteoinductive proteins from demineralized bone and, is required if osteogenesis is to occur. This collagenous delivery vehicle apparently serves a scaffold for the migration into, proliferation, and subsequent differentiation of cells responsible for osteogenesis. In addition, the original form of the collagenous implant dictates the dimensions of the resulting bony tissue. Finally, it is possible to generate an osteoinductive response in many mammals probably including man with purified xenogenic osteoinductive proteins. In conclusion, there is currently much research investigating the phenomenon of matrix-induced osteogenesis and its potential clinical use. In the past few years, there has been a sharp increase in the number of manuscripts published in this area of connective tissue research. Consequently, if the current trend continues, clinicians in the near future can look forward to seeing this material being developed into a convenient "off the shelf" bone replacement system which stimulates host bone formation and repair of cranio-facial osseous defects.