The Degree to Which Attrition Characterizes Differentiated Patient Groups of Temporomandibular Disorders

Dental attrition severity as the cumulative record of parafunctional and functional wear was graded from study cast analysis using established methodology. Attrition severity was compared in anterior, posterior mediotrusive, and posterior laterotrusive segments. Attrition scores in 48 female and 100 male totally asymptomatic controls were compared to 239 female and 31 male patients differentiated into five patient groups of temporomandibular disorders: (1) disc displacement with reduction, (2) disc displacement without reduction, (3) osteoarthrosis with a history of prior derangement, (4) osteoarthrosis without a history of prior derangement, and (5) myalgia only. All the male patients were in the myalgia-only group. Age was controlled in the analysis to control for functional wear. Comparisons between patients and controls were made according to 10-year age intervals. Analysis included ANCOVA confirmed by a Games-Howell post-hoc test, with P < .01 interpreted as a significant difference in the attrition score. Only 1 of 112 ANCOVAs showed a significant difference, with younger men from 20 to 29 years of age in the myalgia-only group having lower mediotrusive attrition than the male controls. It would therefore be difficult if not impossible to differentiate patients from nonpatients based on the severity of dental attrition. Consequently, a major peripheral occlusal etiologic role for attrition in TMD is questioned. Some clinical implications are elaborated.