Experimental Study On Tissue Changes And Biomechanical Evaluation Of Mandibular Lamellar And Linear Fractures In Beagle Dogs

Objective: To analyze the radiological and histological changes in the healing process of mandibular fractures and the biomechanical evaluation of fractures healed at two different fracture type by establishing an animal model of solid internal fixation of mandibular body segments and linear fractures.Method: Eighteen adult healthy Beagles were selected and randomly divided into two groups.Two different types of fractures,lamellar and linear,were formed by osteotomy at the same site of the mandible and fixed with Plates,which were removed at 2 weeks,1 month and 3 months.Results: According to the comparison of imaging pictures,the lamellar group healed faster overall than the linear group,and the comparison of radiographic scores for each time group(P(29)0.05)was not statistically significant.For HE and Masson staining,the lamellar and linear groups were consistent in the form of healing,and the lamellar group was richer in osteocytes and collagen fibers than the linear group.In the 2-week group,there was no statistical significance in stiffness,maximum load,or fracture energy(P(29)0.05)in the lamellar and linear fracture groups.In the 1-month group,maximum load and fracture energy(P(27)0.05)were statistically significant,while stiffness(P(29)0.05)was not statistically significant.In the 3-month group,maximum load,stiffness(P(27)0.05)were statistically significant,and fracture energy(P(29)0.05)was not statistically significant.Biomechanics after healing of laminar fractures was overall better than laminar.The biomechanics of healed laminar fractures were generally better than linear.Concousion:lamellar fractures healed better than linear fractures and healed slightly faster than the linear group.