To what extent are the characteristics of painful temporomandibular disorders predictors of self-reported limitations in jaw function?

Objective: The study evaluated the extent to which the source, intensity, and duration of temporomandibular disorder (TMD) pain are predictors of limitations in jaw function. Methods: The sample included 166 subjects (12-69 years) who self-administered the Jaw Function Limitation Scale (JFLS) and underwent clinical examinations. Results: In univariate correlations, global limitation (long-form JFLS) as well as mastication, mobility, and communication had the highest correlation with headache attributed to TMD (r = 0.362-0.415; p < 0.001). Correlation was higher for pain intensity than chronicity. In multiple regression analysis, significant predictors of jaw limitations (long-form JFLS) were only headache and increasing age (p < 0.001), when controlling for demographic variables, the characteristics of pain, source of pain, and presence of intraarticular disorders. Discussion: Limitation in jaw function is influenced more by pain than by the intracapsular condition and even more so by pain intensity than chronicity.