METHODS: A cross-sectional study was conducted among 784 participants (mean age: 20.9 years; 66.1% female). Validated instruments included the Short-Form Fonseca Anamnestic Index, Patient Health Questionnaire (PHQ)-4, Big Five Inventory-10, PHQ-15 and Oral Behaviours Checklist. Statistical analyses comprised Mann-Whitney U, Chi-square, Spearman's correlation and Hayes' PROCESS macro (Models 1 and 4) to examine moderation and mediation in terms of indirect associations (α = 0.05).

RESULTS: Symptoms consistent with TMDs were identified in 19.0% of participants. Moderate-to-severe psychological distress and somatization were significantly associated with greater TMD symptom severity, higher oral behaviour frequency and specific personality traits. Moderate correlations were observed among psychological distress, somatization, oral behaviours and TMD symptom severity (rs = 0.40-0.53). No significant moderation pathways were detected. Partial mediation pathways indicated indirect associations for psychological distress via agreeableness (β = 0.05), somatization (β = 0.46) and oral behaviours (β = 0.63), and for somatization via psychological distress (β = 0.12) and oral behaviours (β = 0.42).