Comparative evaluation of different miniplates for internal fixation of mandible fractures using finite element analysis

Purpose: In this computer-based study, finite element analysis (FEA) was performed to assess the most suitable shape and fixation technique for a certain type of mandible fracture at corpus. Materials and Methods: A model of the mandible was prepared using computed tomography (CT) scans. The CT scans were transferred and converted to the finite element model by means of a procedure developed for this study. Simulated corpus fractures were fixed with 14 different fixation configurations of titanium miniplates. The FEA was performed with respect to displacement and stresses in the titanium miniplates for these configurations. Results: The study results indicated that the use of 2 straight miniplates is more rigid than other fixation types. Fixation with only I miniplate at the inferior location resulted in mobility greater than the set limit of 150 mu m. With "L" and "T" shaped miniplates and a straight miniplate at the middle location, fracture mobility was approximately equal to or less than the limit; however, displacement nearly reached to limit. Superior fixations with only 1 miniplate resulted in mobility lower than the limit. But these configurations exceed the yield limit of titanium miniplate. Conclusions: FEA may be useful in evaluation of other plate constructs, fracture types, and fracture sites, as confirmed by the agreement between our data and those in the literature and with clinical experience. This analysis should permit us to suggest and evaluate new miniplate designs and enable considerable savings to be made in terms of time, material, and animal experiments in the future development of osteosynthesis materials and techniques. (C) 2008 American Association of Oral and Maxillofacial Surgeons.