Reconstruction of #7 facial cleft with distraction-assisted in situ osteogenesis (DISO): Role of recombinant human bone morphogenetic protein-2 with helistat-activated collagen implant

A case involving concomitant presentation of a #7 lateral facial cleft with a complete cleft of the ipsilateral lip, alveolus, and palate is presented. The mandibular defect was Pruzansky III with a foreshortened body, absent ramus and absent masseter. Taking advantage of developmental field theory, reconstruction of the osseous defect was undertaken using the autogenous periosteum as a source of mesenchymal stem cells. Expansion of the periosteum was followed by implantation of Helistat (Integra Life Sciences, Plainsboro, NJ) collagen sponge saturated with recombinant human bone morphogenetic protein-2. Stimulation of this distraction-induced envelope by rhBMP-2 resulted in abundant production of bicortical membranous bone in situ within 12 weeks. The neoramus was subsequently suspended from the cranial base, and a temporalis muscle transfer was used to provide motor control of the jaw. Synthesis of bone in this manner is termed DISO (distraction-assisted in situ osteogenesis). The biologic rationale and clinical implications of DISO are discussed.