Grants We Funded

Abstract
Currently all popular methods of cleft palate closure rely on the extensive mobilization and transposition of palatal soft tissue flaps in order to close a combined bony and soft tissue defect. Problems associated with this approach include: 1. Extensive scarring along planes of dissection which subsequently restrict facial growth leading to midfacial deformity (Bardach 1990), and 2. A lack of an intact bony palatal arch which leads to unstable dentoalveolar arch form. To minimize these complications related to extensive soft-tissue surgery, closure of cleft palates by sutural distraction osteogenesis has been tested in a canine model (Liu 2000). Successful approximation of the hard palate edges was achieved, however, by a combination of new bone deposition at the palatomaxillary suture (desired) and dentoalveolar arch collapse (undesired). The latter is a complication that limits the clinical feasibility of this approach to cleft palate disease, as it hinders later orthodontic care and significantly deteriorates the final occlusal result. We, however, support the belief that sutural osteodistraction could be a viable therapeutic option pending elimination of associated arch collapse. Our goal is to demonstrate that arch collapse during distraction can be prevented by utilizing a passive maxillary acrylic splint to anchor the alveolus in place while tension forces are applied across the cleft palate. Furthermore, we will investigate the ultrastructural details of distracted palatal suture using state-of-the-art imaging technology (PQ CT and DXA, see below), in addition to standard histological and radiological techniques. Expression of bone morphogenetic proteins (BMPs) and their receptors, known mediators of osteogenesis in non-sutural distraction, will also be characterized temporally and spatially by our basic science collaborator. These new technologies have not previously been used to analyze sutural distraction osteogenesis, and will provide valuable information regarding the structural integrity of generated bone, in addition to a better understanding of the peptide mediators and potential pharmacologic enhancements of this process. In summary, achieving closure of a palatal cleft by suture distraction without arch collapse may have exciting clinical implications for human infant care by minimizing extensive soft tissue surgery. The benefits would include significantly decreased infant surgical morbidity and reduced growth abnormalities contributed to by scarring along surgical planes.