Tooth Wear Severity and Temporomandibular Joint Degenerative Findings on Cone-Beam Computed Tomography: A Cross-Sectional Study in Adults.

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, flattening 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.