Psychosocial–Behavioural Phenotypes and Temporomandibular Disorder Risk: Insights From a Latent Class Analysis in Southeast Asian Young Adults

Background Psychosocial and behavioural factors shape temporomandibular disorders (TMDs), yet integrated phenotyping in Southeast Asian young adults remains limited. University students, a vulnerable subgroup of young adults, face heightened risk. Objectives To identify latent psychosocial–behavioural classes in this cohort and assess associations with sociodemographic factors and TMD severity. Methods A cross‐sectional study of participants aged 18–30 years used validated instruments to assess distress (Patient Health Questionnaire‐4; PHQ‐4), somatic symptoms (PHQ‐15), oral behaviours (Oral Behaviours Checklist; OBC), and TMDs (Short‐form Fonseca Anamnestic Index; SFAI). Latent class analysis (LCA) was performed on PHQ‐4, PHQ‐15, and OBC scores, estimating one‐ to five‐class models. Class differences were tested using χ 2 and Kruskal–Wallis/Dunn's procedures. Predictors of class membership were evaluated using multinomial logistic regression ( α = 0.05). Results Three classes emerged: Resilient (56.1%), Moderate‐Vulnerability (30.4%), and High‐Risk (13.5%). TMD prevalence was highest in High‐Risk (45.0%), intermediate in Moderate‐Vulnerability (25.6%), and lowest in Resilient (10.0%). Depression (OR = 12.34), anxiety (OR = 13.03), somatic burden (OR = 4.91), and oral behaviours (sleeping‐state OR = 1.77; waking‐state non‐functional OR = 1.70; waking‐state functional OR = 1.44) significantly predicted High‐Risk membership. Sociodemographic factors and TMD severity differentiated classes descriptively but lacked predictive strength. Conclusion LCA delineated three psychosocial–behavioural phenotypes, with depression, anxiety, and somatic burden most strongly defining High‐Risk membership, and oral behaviours adding incremental risk. Findings underscore upstream psychosocial–behavioural determinants as key prevention targets, while downstream outcomes guide tailored interventions in young adults.