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 autogenous cranial bone grafts restricts craniofacial growth less than metal plates in 7-week-old Yorkshire pigs. A rectangular 10 x 20 mm segment of bone centered on the right coronal suture was resected. Animals were randomly assigned to one of three experimental groups: (1) rigid fixation across the defect using the bone graft rotated 90 degrees and attached with four microscrews; (2) rigid fixation across the defect using two microplates attached with four microscrews; or (3) no rigid fixation, with four microscrews placed to serve as radiologic markers. All animals were followed up with serial radiographs, and 8 months after the surgery direct measurements were performed on dry skull preparations. 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 significantly greater in the bone plate group, suggesting that a growth center may have been reoriented.