Validation of a Temporary External Fixator for Mandibular Reconstruction: A Biomechanical and Finite Element Analysis

Mandibular reconstruction after tumor resection requires stable fixation that restores function and facial symmetry while minimizing invasiveness. This study presents and validates a bicortical screw–plate Temporary External Fixator (TEF) designed to enhance early-stage mandibular stabilization through optimized geometric configuration. An integrated approach combining finite element analysis (FEA) and experimental compression testing was employed to evaluate biomechanical performance under physiologically representative masticatory loads. Finite-element models of three TEF configurations (2-, 3-, and 4-screw) were analyzed using isotropic and anisotropic bone properties. Loads were applied as a static 600 N and a cyclic half-sine waveform. The 3-screw configuration exhibited the highest stiffness of 272.7 N/mm, lower peak cortical stress (26.49 MPa), and energy absorption of 0.96 J. The experimental tests on 3D-printed resin mandibles closely matched the FEA predictions , with displacement deviations below 5%, confirming the model’s predictive reliability. The results highlighted that strategic screw placement and spacing had a larger impact on biomechanical performance than screw count alone. The proposed TEF demonstrated favorable structural efficiency, procedural simplicity, and cost-effectiveness. The computational-experimental framework established in this work supports future patient-specific optimization and fatigue-life studies for the development of next-generation external fixators in mandibular reconstruction.

Biomechanical performance; Finite element analysis; Mandibular reconstruction; Screw-Plate system; Temporary external fixator

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