LONG-TERM STABILITY OF 2 DIFFERENT MANDIBULAR BRIDGING SYSTEMS

To evaluate the benefits of narrow-beam roentgenography and spiral tom ography for examination and monitoring of screw and plate fixation to bone we studied 22 rigid plate bridgings of mandibular defects. The pl ate reconstructions were of long duration or considered permanent. In 13 patients, AO-THORP (AO: Arbeitsgemeinschaft fur Osteosynthesefragen ; THORP: Titanplasma-beschichteten Hohl- und Vollkern-Rekonstruktionsp latten-Systems) reconstructions were used and in nine classic AO stain less steel plate bridgings. With the AO-THORP system, good bone apposi tion to the screws was evident in 96% (73/76 screws) of the cases. Fix ation using the classic AO screws, however, was inadequate in 30% (20/ 66 screws) of the cases. Plate loosening was noted in 56% (5/9 plates) . Examination using narrow-beam roentgenography and spiral tomography provided detailed information about bone resorption around the screws and provided a reliable tool for deciding on a follow-up regimen. When complications occur, they can be detected and treated early, reducing patient morbidity. In our opinion, classic AO plate bridging should a lways be considered temporary.