Assessment of chronic overlapping pain comorbidities for the management of temporomandibular disorders: Secondary analysis of a randomized clinical trial.

Background: Chronic painful temporomandibular disorders (TMD) are a functional pain syndrome that embodies a spectrum of clinical manifestations and expresses great complexity through the coexistence of multiple comorbidities.

Objective: Evaluate the prevalence of pain comorbidities, explore the correlation between comorbidities, kinesiophobia, catastrophizing, and pain disability at baseline, and determine variables of interest for prediction response to physiotherapy interventions at different follow-up times.

Methods: This is a secondary analysis of a previously conducted randomized controlled trial (RCT). Outcomes and covariables for this secondary analysis were collected from subjects with chronic TMD (≥3 months), based on the DC/TMD diagnostic criteria, assigned to a multimodal treatment and a second manual therapy control group. The participants underwent follow-up assessment at 7 and 19 weeks. The outcomes (dependent variables) for these analyses were craniofacial pain disability, catastrophizing, and kinesiophobia. However, these outcomes were also used as covariables of interest in addition to comorbidity prevalence and severity at baseline for different analyses. We performed linear regression analyses to determine the association between our outcomes and covariables at baseline and at different follow-ups.

Results: Comorbidity severity explained craniofacial pain disability at baseline, showing a strong correlation (Standardized B: 0.40, p-value: 0.017). Higher comorbidity severity, led to higher craniofacial pain score. Comorbidity severity and baseline catastrophizing predicted a better response to treatment for craniofacial pain improvements at short and long term (R² .22, p-value : 0.009 and R² .19, p-value: 0.02 respectively).

Conclusion: This study provides insight into the prevention and clinical management of chronic pain related to TMD.