Controlled structural compliance for improved mandibular fracture fixation using finite element analysis

Mandibular fractures are the most common maxillofacial injuries, and the mechanical performance of fixation systems is a critical factor in addressing the associated clinical challenges. This study presents a systematic finite element analysis (FEA) comparing seven titanium miniplate configurations, including hinge-integrated and dual-plate designs, to identify an optimized construct for symphysial fracture fixation, in contrast to the commonly used single-plate systems that are associated with a notable history of mechanical failure. Using CT data, a heterogeneous three-dimensional mandible model with a clinically relevant fracture pattern was reconstructed, and realistic musculoskeletal loading conditions were simulated to evaluate stress distribution, strain behaviour, and load-transfer characteristics across the bone-miniplate complex after fixation. Different miniplate configurations with varying degrees of freedom and stiffness were modelled and analysed to determine an optimal biomechanical solution. The double miniplate system with hinge joints at both plate ends (Model-5) produced the most favorable biomechanical response, showing the lowest mandibular stress (72 MPa), moderate physiological strain (0.0043), and low plate stress (~166 MPa), demonstrating an improved stiffness-flexibility balance and enhanced load sharing. These findings support hinge-integrated dual-plate constructs as a mechanically balanced alternative for improved fracture stability and long-term durability.