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Straight Segment Mandibulectomy: A Reproducible Porcine Mandibular Critical Size Defect Model

Published:November 03, 2022DOI:https://doi.org/10.1016/j.bjoms.2022.11.003

      Abstract

      Background

      Porcine mandibular defect models are commonly performed for pre-clinical evaluation of reconstruction techniques. Existing studies vary in technique, complexity, and post-operative outcomes. The procedures are complex and often described without sufficient detail. We describe in detail a simple and reproducible method for creating a critical-sized mandibular defect in a porcine model.

      Materials and Methods

      Seven hemi-mandibular critical size defects were created in five male Yorkshire-Landrace pigs - three animals with unilateral defect; two animals with bilateral defects. A transverse incision is made over the mandibular body. Periosteum is incised and elevated to expose the mandibular body. A critical-sized defect of 30 x 20mm is created using an oscillating saw. The implant is inserted and fixation performed with a titanium reconstruction plate with bicortical locking screws. The wound is closed in layers with resorbable sutures.

      Results

      Intra-oral contamination was avoided. Dentition was retained. Mental nerve and its branches were preserved. The marginal mandibular nerve was not encountered during dissection. All pigs retained normal masticatory function. There were no cases of infection, wound breakdown, hematoma, salivary leak or implant-related complications. The procedure can be performed bilaterally on both hemi-mandibles without affecting its load-bearing function. All pigs survived until the end-point of 3 months. Post-operative computed tomography scans and histology showed new bone formation. Three-point bend test showed restoration of biomechanical strength.

      Conclusions

      Straight-segment mandibulectomy is a simple and reproducible method for creating critical size mandibular defects in a porcine model, simulating a load-bearing situation.

      Keywords

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