Material analysis of AO plate fracture cases.

PURPOSE: The clinical observation of fracture cases and material evaluation of fractured titanium plates were performed to investigate the causes of fracture.

PATIENTS AND METHODS: Fracture of titanium plates occurred in 4 patients of the 110 mandibular reconstructions. We clinically and experimentally evaluated plate fracture cases among cases in which primary reconstruction using titanium plates was performed after the mandibular resection.

RESULTS: Titanium plate fracture was frequently observed in L-type defect cases in which angle-type plates were used, and fracture mainly occurred in the anterior region of the mandibular angle. Material analysis suggested that the occurrence of fracture can be prevented by eliminating constricted parts on the internal side of the plates.

CONCLUSIONS: The causes of fracture were thought to be the use of plates under the conditions of comparatively frequent repeated application of stress or fatigue fracture caused by stress concentration, depending on the form of the plate.