The purpose of the present study is to compare the plate geometries and materials for calculating stress distributions and displacements. A model of the mandible was modeled aided with computed tomography (CT) images. The CT images were converted to the finite element model aided by reverse engineering methodology. 3 materials for mini plate and fixators (Titanium Alloy, Chrome-Cobalt and Stainless Steel) were designed with different geometry variations ("Y", "I" and "Square") and two different fracture types (linear and oblique). The finite element analyses (FEA) (In Slico) were performed with respect to displacement and stress distributions for both mandibula and fixators. According to all FEA results, "Square" type fixators for linear fracture type had a minimum stress distribution. In addition, the "I" type double fixators (for oblique fractures) with titanium alloy have more favorable stress distribution and also chrome-cobalt material for have best displacement results than the others. FEA is useful for comparing geometry and material variations of rigid mandibular fixations. The finite-element method showed that when selecting mini plate we consider geometry and material variations.