Multidimensional Factors Associated With Self‐Reported <scp>TMD</scp> Symptom Burden in Young Adults With <scp>DC</scp> / <scp>TMD</scp> ‐Defined Myalgia

BACKGROUND: This study aimed to examine multidimensional factors associated with self-reported Temporomandibular Disorders (TMD) symptom burden, assessed using the Fonseca Anamnestic Index (FAI), in young adults with myalgia defined according to the Diagnostic Criteria (DC) for TMD. METHODS: This cross-sectional study included 104 young adults with myalgia diagnosed according to the DC/TMD criteria. TMD symptom burden was assessed using the FAI. Clinical, psychosocial, and ultrasonographic variables were evaluated. Backward multiple linear regression was used to identify variables associated with higher FAI scores. RESULTS: = 0.530, p < 0.001). Higher activity-related pain, greater neck disability, elevated anxiety levels, and a higher number of parafunctional activities were positively associated with higher FAI scores, whereas greater right masseter muscle thickness was inversely associated with FAI scores (p < 0.05). CONCLUSIONS: Self-reported TMD symptom burden among young adults with DC/TMD-defined myalgia was associated with functional pain, cumulative parafunctional behaviors, neck disability, anxiety, and masseter muscle thickness. These findings support a multidimensional perspective in the assessment of TMD-related symptoms in individuals with myalgia and highlight the need for longitudinal studies using diagnostically grounded designs.