The Contribution of Insomnia and Obstructive Sleep Apnea on the Transition from Acute to Chronic Painful Temporomandibular Disorders and their Persistence: A Prospective 3-Month Cohort Study

Background: Insomnia, and Excessive Daytime Sleepiness (EDS), a surrogate marker of Obstructive Sleep Apnea (OSA), are common sleep-related conditions among painful temporomandibular disorders (TMD) patients. OSA was found to increase the risk of chronic painful TMD.Aims: This prospective cohort study aims to determine the contribution of insomnia and EDS on acute to chronic painful TMD transition as well as its persistence when chronic pain is defined by: (i) duration (> 3 months), and (ii) dysfunction (Graded Chronic Pain Scale [GCPS II-IV]).Methods: From 456 patients recruited between 2015 to 2021, through four locations in Canada, 378 completed the follow-up. A diagnosis was obtained using the Research Diagnostic Criteria or the Diagnostic Criteria for TMD. Insomnia was assessed with the Insomnia Severity Scale (ISS), and OSA was assessed using the Epworth Sleepiness Scale (ESS) which measures EDS, both at baseline. Patients completed the GCPS form at baseline and 3-month follow-up.Results: Borderline associations were found between EDS and the transition or persistence of chronic painful TMD when chronic pain was defined by pain duration (RR (adjusted_duration) = 1.11, P = 0.07) and dysfunction (RRadjusted_dysfunction =1.40, P = 0.051). Furthermore, EDS was specifically associated with persistent painful TMD when chronic pain was defined by pain duration (RR = 1.13, 95%CI: 1.00-1.26, P = 0.04). Insomnia was not related to the study outcomes (RRadjusted_duration = 0.94, P = 0.27, RRadjusted_dysfunction =1.00, P = 0.99). Conclusion: Results indicate that EDS contrary to insomnia predicted the persistence of chronic painful TMD at a 3-month follow-up.