Sleep‐Severity Profiles in Temporomandibular Disorder: A Cluster‐Analytic Approach to Identifying Biopsychosocial Subgroups

ABSTRACT Background Painful temporomandibular disorders (TMDs) are frequently comorbid with sleep disturbance, yet heterogeneity in sleep profiles remains poorly characterized. Objectives To identify sleep‐severity profiles in adults with and without TMD and examine their psychological correlates. Methods Eighty‐four adults (32 TMD, 52 controls) completed the Pittsburgh Sleep Quality Index (PSQI) and measures of psychological symptoms (SCL‐90‐R), body vigilance (BVS), positive and negative affect (PANAS), and trait anxiety (STAI). Sleep‐severity profiles were derived by principal component analysis of the PSQI components and hierarchical clustering, and their diagnostic composition was compared by chi‐squared test. Psychological outcomes were reduced based on their intercorrelation structure and analysed by two‐way MANCOVA (Profile × TMD status), covarying age and sex. Results Two profiles emerged: Mild–Moderate ( n = 59; PSQI M = 5.25) and Severe Poor Sleepers ( n = 21; PSQI M = 9.19), TMD being concentrated in the Severe profile (χ 2 (1) = 9.35, p = 0.002). The outcomes reflected a single general‐distress dimension indexed by the SCL‐90‐R Global Severity Index (GSI). GSI therefore served as the primary outcome, with body vigilance and affect tested with that dimension partialled out. Profile and Profile × TMD effects were significant (TMD main effect, n.s.), both carried by general distress: distress was elevated in the Severe profile (η 2 p = 0.17), and the interaction (η 2 p = 0.16) reflected distress rising with sleep severity in controls but uniformly elevated in TMD. No effect was specific to body vigilance or affect. Conclusion Severe self‐reported sleep disturbance was associated with psychological distress comparable to that of TMD; these exploratory findings require replication with objective sleep and pain measures.