The contribution of insomnia and obstructive sleep apnea on the transition from acute to chronic painful temporomandibular disorders, and its persistence: a prospective 3-month cohort study

Insomnia and excessive daytime sleepiness, a surrogate marker of obstructive sleep apnea, are common sleep-related conditions among painful temporomandibular disorders (TMD) subjects. Obstructive sleep apnea was found to increase the risk of chronic painful TMD. This prospective cohort study aims to determine the contribution of insomnia and excessive daytime sleepiness (ESS/OSA) 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]). From 456 subjects 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 Temporomandibular Disorders. Insomnia was assessed with the Insomnia Severity Scale (ISS), and excessive daytime sleepiness was measured using the Epworth Sleepiness Scale (ESS/OSA), both at baseline. Subjects completed the GCPS form at baseline and 3-month follow-up. Borderline associations were found between ESS/OSA 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, ESS/OSA 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). Results indicate that ESS/OSA contrary to insomnia predicted the persistence of chronic painful TMD at a 3-month follow-up.