ABSTRACT
<p><b>OBJECTIVE</b>To determine the biomechanical characteristics of mandibular fractures in different site.</p><p><b>METHODS</b>Nine adult mandibular specimens were measured precisely. The data was used to establish a three-dimensional model. When mandibular was under functional loading, the bending and torsion moment as well as shear force of angle, body and symphyseal fracture was calculated. The data were analyzed by Origin 6.0 software.</p><p><b>RESULTS</b>Angle fracture had relatively high positive bending moment and high shear force. Body fracture had positive as well as negative bending moment and the highest torsion moments. Symphyseal fracture had only negative bending moment and relatively low shear force.</p><p><b>CONCLUSION</b>Angle, body and symphyseal fractures each have a biomechanics characteristic. These biomechanics characteristic should have an important meaning in the treatment of mandibular fractures and instructing patient how to bite correctly.</p>