GEOMETRIC CONSIDERATIONS OF DISK REPOSITIONING PROCEDURES

One approach to treatment of internal derangements of the temporomandi bular joint (TMJ) is surgical remodeling and repositioning of the disk and its attachments. Nine joints exhibiting disk displacements (four histological series and five magnetic resonance imagining (MRI) series ) were studied to analyze the geometrical and mechanical implications of surgical repositioning. In the central tomographic plane, for examp le, these cases would have required repositioning the disk 6.9 mm post eriorly (+/- 3.3 mm), removing 5.2 mm (+/- 1.6 mm) of remodeled retrod iskal tissue, and trimming 2.1 mm (+/- 2.0 mm) of disk. This suggests that from gross geometric considerations alone, there is not sufficien t viable joint tissue to recommend disk repositioning as a routine pro cedure.