Association of occlusal variables among refined TM patient diagnostic groups.

One hundred ninety-six TMJ patients differentiated into five diagnostic groups (disk displacement with reduction [n = 40], disk displacement without reduction [n = 14], TMJ osteoarthrosis with a history of past locking [n = 32], TMJ osteoarthrosis without a history of past locking [n = 30], myalgia only [n = 80]) were compared with 222 nonpatient controls for specific occlusal variables. The patient groups could not be differentiated according to the absence of RCP-ICP slide per se, crossbite, or symmetry of RCP contacts. Among males with reducing disk displacement, Class I was less common and Class II division 1 was more common than in controls. Asymmetric RCP-ICP slides and a combination of unilateral RCP contact and no clinically visible RCP-ICP slide were more prevalent in women with reducing disk displacement. Large RCP-ICP slides, asymmetric slides, and anterior open bite were associated with osteoarthrosis, but this study could not state if these associations were etiologic or secondary. Totally asymptomatic controls were characterized by a lack of anterior open bite, small symmetric RCP-ICP slides (greater than 0 less than 1 mm), and bilateral occlusal contact in RCP. By comparing a control group to well-defined patient diagnostic groups rather than according to symptoms, selective occlusal variables appear more closely associated with some TMJ disorders than indicated in past studies with less specific populations.