A three dimensional numerical interaction model for the fixation of mandibular fractures

Two and three dimensional finite element models (FEM) were developed to simulate the behavior of a fractured jaw bone and the fixation materials. Mini-plates with various geometric and material properties and screw combinations were considered. Their effects on the variation of maximum stress contours were investigated. The geometric and material properties of the plate, screw and bone were seen to play important roles in effecting the relative displacement at the fractured surface and the spatial variation of the maximum stress across the jaw bone. Softer materials yielded less stress concentrations around the screws while increasing the relative deformation at the fractured surface and stiffer ones caused higher stress concentrations while decreasing the displacements. Results were also seen to be dependent on the loading and the need for the use of patient specific 3D solutions was emphasized.