Tooth wear severity and temporomandibular joint degenerative findings on cone-beam computed tomography: A cross-sectional study in adults

Abstract

Background: Tooth wear is commonly assumed to be a marker of parafunctional load and, by extension, of mechanical stress on the temporomandibular joint (TMJ); whether greater wear accompanies greater degeneration in the same joint has rarely been tested. Objective: To determine whether tooth wear severity is associated with ipsilateral CBCT- detected TMJ degeneration in adults with TMD symptoms. Methods: In this cross- sectional study, 80 adults (160 joints; mean age 27 years; 80% female) underwent standardised tooth- wear scoring (Smith and Knight index, 0–4) and blinded CBCT assessment of osteophyte, erosion, subchondral cyst, flat tening and sclerosis, categorised as no, indeterminate or definite osteoarthritis by established imaging criteria. Side- wear was modelled against same- side findings with generalised estimating equations for paired- joint clustering, and patient- level wear by logistic regression, adjusted for age, sex and Angle class with Bonferroni correction across the prespecified primary outcomes. Results: Osseous findings were prevalent (flattening 86.9%, osteophyte 50.0%, erosion ≥ Grade 1 66.2%) and 75.6% of joints met criteria for definite osteoarthritis. Tooth wear showed no association with any joint outcome: adjusted odds ratios per +5 side- wear clustered around unity for osteophyte (1.01, 95% CI 0.79–1.27), subchondral cyst (1.00, 0.76–1.32) and definite osteoarthritis (0.95, 0.71–1.27), none reaching Bonferroni- corrected or nominal significance. Patient- level analyses were similarly null. Wear increased with age (Spearman ρ = 0.65, p < 0.001). Conclusion: Tooth wear severity was not associated with ipsilateral TMJ degeneration. The assumed positive link with TMJ osseous change was not observed; wear alone does not appear to be a reliable clinical proxy for joint loading.