Comparison of tensile strength of resorbable plating systems used in monocortical mandible angle osteotomy repair.

OBJECTIVE To determine the usefulness of resorbable plating systems in load-bearing applications of the mandible and the location of critical failure. METHODS An osteotomy was created in 24 fresh cadaveric mandibles at the angle and fixated by the Champy technique with similar resorbable craniofacial plating systems from 4 manufacturers. Each mandible was held rigid as a material test system applied a downward force anteriorly. The critical tolerance was measured and the type of failure was noted. RESULTS Critical failure occurred at forces from 34.6 to 137.8 N. We found a statistically significant difference between the plating groups (P<.001 for all comparisons). The point of failure was almost uniformly at the plate. CONCLUSIONS Critical failure was overwhelmingly due to rupture of the plate rather than to stripping or shearing of the screws as had been strongly expected. We found differences in plate strengths for this particular application and did not evaluate their respective long-term resorptive properties. We do not advocate that single resorbable plate fixation be the sole means of mandible angle fracture fixation, regardless of the plating system used.