Biomechanical evaluation of resorbable and titanium miniplates and of single and double miniplates for the treatment of mandibular condyle fractures

Mandibular condyle fractures are one of the most common facial bone fractures, and open reduction, which involves implanting miniplates to ensure rigid fixation of the fractured surfaces, is the standard treatment. The aim of this study was to compare the stress fields of resorbable and titanium miniplates and of single and double miniplates by taking the displacement between the fracture surfaces (interfragmentary displacement) into account. Three-dimensional mandible models were created based on computed tomography images from 10 patients. To simulate the common loading conditions that the mandible is exposed to during daily living, mastication and muscle forces were applied to each model. The von Mises stress distribution over the miniplates and the maximum displacements between the fractured surfaces were calculated using finite element analysis. The mean maximum stresses associated with the titanium miniplates were significantly higher than those associated with the resorbable miniplates (p < 0.05). Moreover, the mean maximum inter-fragmentary displacements associated with the resorbable miniplates were higher than those associated with the titanium miniplates, but there was no significant difference (p > 0.05). The stress and interfragmentary displacement results associated with the single and double miniplates (made of either of the two materials) were within the clinically acceptable limits. (C) 2019 Nalecz Institute of Biocybernetics and Biomedical Engineering of the Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.