Migraine As Predictor For Pain Intensity For Tmd Patients Undergoing Treatment

Abstract

Introduction: Temporomandibular disorders (TMD) occur in about 10% of the adult general population, which makes it a considerable public health problem. Some factors affect treatment outcome of TMD patients seeking care, and among the factors influencing the prognosis of TMD pain, are comorbid pain conditions. Headaches, particularly migraine, have long been reported to be more frequently associated in TMD patients. However, evidence is lacking whether migraine is a prognostic factor for TMD pain at follow-up for patients undergoing TMD treatment. Objective: To determine in TMD pain patients who undergo common non-surgical treatments whether the presence of migraine at time of diagnosis is associated with worse TMD pain intensity at follow-up over a time period of 18 months. Materials and Methods: In this prospective cohort study, a consecutive sample of 99 patients with a diagnosis of TMD pain consisting of MFP, arthralgia, and/or TMJ osteoarthritis according to RDC/TMD seeking care at the TMD and Orofacial Pain Clinic, University of Minnesota - School of Dentistry and undergoing common non- surgical treatments for TMD were recruited. Participants received a diagnosis of migraine according to International Classification of Headache Disorders 2nd edition (ICHD-II, 2004), the study exposure, at baseline. Characteristic pain intensity, the study outcome, was measured at 1, 6, 12 and 18 month follow-up and CPI differences at follow-up between patients with and without migraine were analyzed with several generalized equation estimation models and model selection was performed with QIC (Quasilikelihood under the Independence model Criterion). Baseline CPI status and sociodemographic variables were added to improve the model. Results: At time of diagnosis (baseline), patients with migraine had a CPI level of 53.9 (95% CI: 43.2-64.6) and patients without migraine had a CPI level of 55.8 (95% CI: 51- 60.5). At follow-up, CPI had decreased in both groups but patients with migraine had more pain. The statistically best fitting model predicted CPI values of 45.8, 38.4, 34.8 and 29.2 at 1, 6, 12, and 18 months, respectively for patients without migraine. Patients with migraine showed model-predicted differences, additional CPI compared to patients without migraine, of 10.6 (95% CI: -1.6 -22.9), 8.7 (95% CI: -8.0-25.4), 5.4 (95% CI: - 7.3-18.2) and 16.5 (95% CI: 5.2-27.8) at 1, 6, 12, and 18 months, respectively. According to guidelines to interpret effect sizes, the effect was "small."� A simple, more interpretable and still statistically well fitting model predicted that CPI decreases 0.96 per month during follow-up and patients with migraine have 11.6 (95% CI: 2.7-20.4) more CPI over the time period of 1.5 years than patients without migraine. Conclusion: For TMD patients who undergo common non-surgical treatments, migraine is a potential prognostic factor for TMD pain intensity at follow-up. Patients with migraine at the time of diagnosis have statistically significant more TMD pain intensity over a time period of 1.5 years than patients without. While the migraine effect is small, it suggests that treatment for migraine could possibly be incorporated in the overall treatment plan to improve patient outcomes.