Demographic and structural indicators of temporomandibular joint osteoarthritis in asymptomatic adults: a cone-beam computed tomography-based multivariate analysis

Abstract Objective To investigate demographic, morphologic, and morphometric variables associated with early or subclinical imaging-based osteoarthritic structural changes of temporomandibular joint (TMJ). Methods Cone-beam computed tomography scans of 396 TMJs from 198 asymptomatic individuals (75 males, 123 females) were analyzed. TMJs were classified as normal-appearing, indeterminate for osteoarthritis (OA), or affected by OA based on condyle, and fossa/eminence morphology. Univariate and multivariate logistic regression models assessed the association of 5 patient-level and 20 TMJ-level variables with the indeterminate or affected by OA status, adjusting for confounding. Results Prevalence rates of the indeterminate and affected by OA statuses were 25.80% and 33.30% at the patient-level and 25.30% and 24.50% at the TMJ-level, respectively. Whereas complete/partial edentulism was the only strong/independent indicator for indeterminate for OA category, strong indicators associated with the affected by OA status included age > 38.50 years, complete/partial edentulism, Class II skeletal relationship, horizontal condylar angle ≥ 24.14 degrees, condylar height ≤ 16.00 mm, sagittal glenoid fossa width > 16.95 mm, sagittal articular eminence angle ≤ 45.78 degrees, glenoid fossa roof thickness > 1.23 mm (coronal) and > 1.20 mm (sagittal). Conclusions CBCT imaging provides a reliable framework for identifying both established and early osteoarthritic changes in the TMJ of asymptomatic adults. Indeterminate cases, often marked by flattening or sclerosis, should be regarded as transitional stages that warrant closer monitoring.