Cross-Sectional Study of The Association of Masticatory Muscle Pain Diagnostic Subgroups with Biopsychosocial Factors

Abstract

Aim: Clinically, it would be useful to determine if the varied temporomandibular disorders differ in their biopsychosocial characteristics. The aim of this study was to assess differences in biopsychosocial factors among participants with masticatory myofascial pain (MFP) with referral, myalgia without referral, and community controls. Methods: The original Validation Project sample included 196 participants with MFP with referral (Group 1), 299 with myalgia without referral (Group 2), and 87 community controls (Group 3). Two calibrated examiners at each of 3 sites rendered these consensus-based diagnoses. Data regarding biological factors was collected including pain duration, number of painful sites to palpation and pressure pain thresholds (PPT) at 12 masticatory muscle sites, 2 trigeminal controls sites and 2 non-trigeminal control sites. Psychosocial factors were also assessed including anxiety, depression, and nonspecific physical symptoms using the Symptom Checklist-90 Revised (SCL-90R), stress using the Perceived Stress Scale (PSS) and health related quality of life (HRQoL) using the Short Form Health Survey (SF-12). Multivariable linear regression was used for comparisons among the three groups adjusting for age, sex, race, education, and income. For subsequent pairwise-comparisons, the significance threshold was set at p=0.05/3=0.017. Results: Participants with MFP with referral had significantly greater pain duration, lower PPTs in trigeminal sites, and thus the highest pain sensitivity, as well as more painful sites, compared to participants with myalgia without referral and controls. Participants with MFP with referral also had significantly greater symptoms of anxiety, depression, nonspecific physical symptoms, and impaired physical health. Although stress was higher and the mental component of HRQoL was lower for myofascial pain with referral as compared to the myalgia without referral and control groups, the differences between the two muscle pain groups were not statistically significant. Conclusion: These findings suggest that the clinical diagnosis of MFP with referral has clinical utility in the identification of masticatory muscle pain patients with the highest pain sensitivity and most complex biopsychosocial characteristics. Patients with this diagnosis may benefit from treatments specifically addressing these characteristics.