Determination of critical-sized defect of mandible in a rabbit model: Micro-computed tomography, and histological evaluation

ObjectiveTo evaluate a rabbit model of mandibular box-shaped defects created through an intraoral approach and determine the minimum size defect that would not spontaneously heal during rabbit's natural life (or critical-sized defect, CSD).MethodsForty-five 6-month-old rabbits were randomly divided into five groups (nine each). Mandibular different sizes (4, 5, 6, 8, 10 mm) in each hemimandible, with same width depth (3 2 mm, respectively). Four, 12 weeks post-surgery, three animals per group euthanized. New bone formation was assessed using micro-computed tomography (MCT) histomorphometric analyses.ResultsBox-shaped successfully buccal region between incisor area anterior part mental foramen mandibles. Twelve MCT analysis showed 4, 6 mm filled new bone, while those 8 remained underfilled. Quantitative revealed mass recovery percentage significantly lower than other (p < 0.05). There no significant difference > Histomorphometric indicated remaining 0.05).ConclusionsThe dimensions CSD mandible × 3 mm. This may provide clinically relevant base for future tissue engineering efforts mandible.