Reliable critical sized defect rodent model for cleft palate research

BackgroundSuitable animal models are necessary to test the efficacy of new bone grafting therapies in cleft palate surgery. Rodent models of cleft palate are available but have limitations. This study compared and modified mid-palate cleft (MPC) and alveolar cleft (AC) models to determine the most reliable and reproducible model for bone grafting studies.MethodsPublished MPC model (9 × 5 × 3 mm3) lacked sufficient information for tested rats. Our initial studies utilizing AC model (7 × 4 × 3 mm3) in 8 and 16 weeks old Sprague Dawley (SD) rats revealed injury to adjacent structures. After comparing anteroposterior and transverse maxillary dimensions in 16 weeks old SD and Wistar rats, virtual planning was performed to modify MPC and AC defects dimensions, taking the adjacent structures into consideration. Modified MPC (7 × 2.5 × 1 mm3) and AC (5 × 2.5 × 1 mm3) defects were employed in 16 weeks old Wistar rats and healing was monitored by micro-computed tomography and histology.ResultsMaxillary dimensions in SD and Wistar rats were not significantly different. Preoperative virtual planning enhanced postoperative surgical outcomes. Bone healing occurred at defect margin leaving central bone void confirming the critical size nature of the modified MPC and AC defects.ConclusionsPresented modifications for MPC and AC models created clinically relevant and reproducible defects.