Application of purified bone morphogenetic protein (BMP) preparations in cranio-maxillo-facial surgery. Reconstruction in craniofacial malformations and post-traumatic or operative defects of the skull with lyophilized cartilage and BMP.

New ways of craniofacial reconstruction in old post-traumatic or fresh donor site craniectomy defects and in congenital malformations (Apert's and Crouzon's syndromes) are described. In all instances a stacked composite of lyophilized cartilage strips interspersed with BMP layers was applied to fill the defects and indentations or used in combination with autologous bone struts to rebuild the cranium completely in synostotic malformations. The stratified implants interlaced with BMP induced early bone formation, and in addition were rigid enough from the beginning to serve as bridging elements over and between autologous bone struts in the cage-like forehead reconstructions. The reconstructed areas became clinically solid after a few months. CT images taken in 4 cases showed progressive calcification starting in the BMP layers, sometimes already visible after a few weeks. These results indicate that the usual slow process of calcification/ossification of lyocartilage alone is considerably accelerated by the combination with BMP. From intermediate term observations (more than one year) we conclude that complete consolidation of the whole implants, so far without signs of resorption, will consistently be the final outcome of this type of reconstruction.