Comparative finite element analysis of the biomechanical stability of 2.0 fixation plates in atrophic mandibular fractures.

PURPOSE: The objective of the present study was to conduct a computational, laboratory-based comparison of the biomechanical stability of 2.0 fixation locking plates with different profiles in Class III atrophic mandibular fractures using 3-dimensional finite element analysis.

MATERIALS AND METHODS: Three-dimensional finite element models simulating Class III atrophic mandibular fractures were constructed. The models were divided into 4 groups according to plate thickness (1.0, 1.5, 2.0, and 2.5 mm). Fractures were simulated in left mandibular bodies, and 3 locking screws were used on each side of each fracture for fixation. Bite forces of approximately 63 N were simulated in the incisor and molar regions of the mandibles in finite element models.

RESULTS: The level of compressive strain on the bone around the screw was within the physiological limit. No significant difference was observed in the displacement of bone segments in the fracture region. Von Mises stress was higher during simulated bites in the molar region for plates with thicknesses of 1.0 mm. Plate tension values were below the level required for permanent deformation or fracture in all models. The 2.5-mm-thick plate presented better biomechanical performance than all other plates. The 2.0-mm-thick plate also showed satisfactory results and adequate safety limits.

CONCLUSION: Large-profile (2.0-mm-thick) locking plates showed better biomechanical performance than did 1.0- and 1.5-mm-thick plates and can be considered an alternative reconstruction plate for the treatment of Class III atrophic mandibular fractures.