A MULTIPLE LOGISTIC-REGRESSION ANALYSIS OF THE RISK AND RELATIVE ODDSOF TEMPOROMANDIBULAR DISORDERS AS A FUNCTION OF COMMON OCCLUSAL FEATURES

A multiple logistic regression analysis was used to compute the odds r atios for 11 common occlusal features for asymptomatic controls (n = 1 47) vs. five temporomandibular disorder groups: Disc Displacement with Reduction (n = 81), Disc Displacement without Reduction (n = 48), Ost eoarthrosis with Disc Displacement History (n = 75), Primary Osteoarth rosis (n = 85), and Myalgia Only (n = 124). Features that did not cont ribute included: retruded contact position (RCP) to intercuspal positi on (ICP) occlusal slides less-than-or-equal-to 2 mm, slide asymmetry, unilateral RCP contacts, deep overbite, minimal overjet, dental midlin e discrepancies, less-than-or-equal-to 4 missing teeth, and maxillo-ma ndibular first molar relationship or cross-arch asymmetry. Groupings o f a minimum of two to at most five occlusal variables contributed to t he TMD patient groups. Significant increases in risk occurred selectiv ely with anterior open bite (p < 0.01), unilateral maxillary lingual c rossbite (p < 0.05 to p < 0.01), overjets > 6-7 mm (p < 0.05 to p < 0. 01), greater-than-or-equal-to 5-6 missing posterior teeth (p < 0.05 to p < 0.01), and RCP-ICP slides > 2 mm (p < 0.05 to p < 0.01). While th e contribution of occlusion to the disease groups was not zero, most o f the variation in each disease population was not explained by occlus al parameters. Thus, occlusion cannot be considered the unique or domi nant factor in defining TMD populations. Certain features such as ante rior open bite in osteoarthrosis patients were considered to be a cons equence of rather than etiological factors for the disorder.