COMPARISON OF CRANIOFACIAL GROWTH AFTER RIGID FIXATION WITH AUTOGENOUS BONE PLATES AND WITH METAL PLATES

This study was undertaken to determine whether rigid fixation using au togenous cranial bone grafts restricts craniofacial growth less than m etal plates in 7-week-old Yorkshire pigs. A rectangular 10 X 20 mm seg ment of bone centered on the right coronal suture was resected. Animal s were randomly assigned to one of three experimental groups: (1) rigi d fixation across the defect using the bone graft rotated 90 degrees a nd attached with four microscrews; (2) rigid fixation across the defec t using two microplates attached with four microscrews; or (3) no rigi d fixation, with four microscrews placed to serve as radiologic marker s. All animals were followed up with serial radiographs, and 8 months after the surgery direct measurements were performed on dry skull prep arations. The greatest lengths were in the control group, followed by the bone plate and then the metal plate groups, but these differences were not statistically significant. The cranial width was significantl y greater in the bone plate group, suggesting that a growth center may have been reoriented.