Oral Behaviors, Anxiety, and Depression in Temporomandibular Disorders: A Conceptual Narrative Review Within the...

Background and Objectives: Temporomandibular disorders (TMDs) are heterogeneous conditions whose clinical expression cannot be fully explained by local or structural findings alone. DC/TMD Axis II provides a psychobehavioral framework for assessing pain, disability, jaw functional limitation, psychological symptoms, and oral behaviors. This conceptual narrative review aimed to clarify how oral behaviors, anxiety, and depressive symptoms can be clinically interpreted together within the DC/TMD Axis II framework. Materials and Methods: A structured search was conducted in PubMed/MEDLINE and Scopus, with records exported in March 2026. Eligible English-language publications were limited to January 2001-March 2026. Google Scholar was used as a supplementary verification source. After deduplication, 2756 records were screened, 87 full-text reports were assessed, and 36 publications were included in the final narrative synthesis. Evidence was synthesized thematically and appraised according to study design, population, diagnostic framework, Axis II instruments, self-report reliance, confounding, and inferential strength. Results: Current literature supports associations between oral behaviors, anxiety, depressive symptoms, pain intensity, and mandibular functional limitation in TMD, especially in painful and functionally impaired profiles. These associations are not uniform across all TMD subtypes and are influenced by factors such as sex, pain burden, comorbidities, and psychosocial context. The Oral Behaviors Checklist is useful for standardizing self-reported oral behaviors, but its interpretation is limited by recall, awareness, and reporting bias. Conclusions: The reviewed evidence supports an interactional interpretation of oral behaviors, psychological symptoms, pain, and jaw function within the DC/TMD Axis II framework. However, because most available studies are cross-sectional and self-reported, this model should be understood as a clinically informed hypothesis supported by convergent associations, not as a confirmed causal pathway. Longitudinal and intervention-based studies are needed to clarify directionality, prognosis, and treatment-response relevance.