[Biomechanical studies on various methods of osteosynthesis on a photoelastic model of the mandible]

Biomechanical studies on a model of the mandible served to verify the stability of a fracture treated with the techniques of pressure-plate osteosynthesis, traction-bandage osteosynthesis and percutaneous compression osteosynthesis, respectively. Stress distribution in the model were determined photoelastically. In this way, it has been possible to obtain informations about stresses caused by different loads (biting-off, stress on the left or right lateral region). Of the methods of osteosynthesis under investigation, plate osteosynthesis yielded the most stable union of the fragments. Satisfactory values were also achieved by means of traction-bandage osteosynthesis and percutaneous compression osteosynthesis. Consequently, these methods may be regarded as function-stable. Conclusions as to the optimal location of the osteosynthesis material can be drawn from an exact analysis of the stress curves. Maximum stress on the mandible, especially in the anterior region, should be avoided for a least 3 weeks.