Abstract

A comparative study of most suitable miniplate fixation
for mandibular symphysis fracture using a finite
element model

Akiko Kimura, Tomohisa Nagasao, Tsuyoshi Kaneko, Junpei Miyamoto
and Tatsuo Nakajima

The purpose of this study is to determine the most stable fixation method for mandibularsymphysis fractures by comparing the mechanical characteristics of models fixed at different positionswith different numbers of plates. Fractures were generated in 3-dimensional finite element models, andwere fixed with a single miniplate, parallel double miniplates, or perpendicular double miniplates. A300 N perpendicular load was then applied on the left molar region, and a finite element analysis wasperformed. We compared vertical gaps between the fractured surfaces, maximum stress within thescrew/plating system, and maximum stress around screw holes in the bone. Compared to the singleminiplate, both the parallel and perpendicular double miniplates demonstrated significantly less stressin the screw/plating system and screw holes in the bone. In addition, the perpendicular double miniplateshad significantly smaller vertical gaps between fracture surfaces when compared to the singleminiplate. Comparing parallel and perpendicular double miniplate fixations, less stress was foundaround the screw holes of the perpendicular miniplate models than those of the parallel miniplatemodels. There were no differences in vertical gaps or maximum stress within the screw/plating systemsbetween the 2 double miniplate fixations. These results suggest that perpendicular double miniplatefixation is more suitable for fixing mandibular symphysis fractures.