Strength analysis of titanium and resorbable internal fixation in a mandibulotomy model.

PURPOSE

Mandibulotomy is used to access various tumors of the tongue base, posterior oral cavity, pharynx, parapharyngeal space, and cranial base. Internal fixation using titanium plates and screws is the most common method of stabilization. These have the potential for interference with radiotherapy delivery. This in vitro study compares the strength of titanium and resorbable internal fixation in a mandibulotomy model by analyzing the force required for plate and screw breakage.

MATERIALS AND METHODS

Red oak wood board was used to simulate the mandible. Titanium and resorbable plates and screws in various configurations were used to stabilize pieces of the wood. They were arranged in 6 different groups. The specimens were individually tested with a vertical load, while the test machine recorded the force-versus-displacement behavior automatically.

RESULTS

Plate type and configuration affected the applied load required to induce displacement of the simulated mandibulotomy. Heating and cooling the resorbable plates prior to strength testing also affected the load-versus-displacement curve.

CONCLUSIONS

Overall, the titanium system we studied exhibited greater resistance to deformation from a vertical load than did the resorbable plate groups.