Orofacial pain/headache interlaced to insomnia, sleep apnea and periodic limb movement during sleep/restless leg syndrome: a critical and comprehensive review with insights into social determinants

This critical review explores the intricate interaction between orofacial pain and headache disorders and three prevalent sleep disorders: insomnia, obstructive sleep apnea (OSA) and periodic limb movements (PLMs) during sleep, while integrating the role of social determinants of health. Orofacial pain conditions, including temporomandibular disorders (TMD), headache, and burning mouth syndrome, frequently co-occur with sleep disturbances, creating a bidirectional cycle where poor sleep exacerbates pain and <i>vice versa</i>. The mechanisms underlying this relationship involve disrupted restorative sleep, neuroinflammation, heightened arousal and impaired descending pain modulation. Importantly, social factors such as socioeconomic status, healthcare access, education level, and social support influence the prevalence, severity, and management of these comorbidities, contributing to significant disparities in outcomes. We present recent advances in the phenotyping and endotyping of individuals with sleep-pain comorbidities, which aim to identify subgroups with shared characteristics to guide personalized interventions, emphasizing the need for interdisciplinary approaches that bridge dentistry, sleep medicine and public health to address the multifactorial nature of these conditions. Practical considerations for clinicians managing these patients are discussed, including screening tools, treatment modalities and the impact of social context. Future research directions prioritize the integration of measures of social factors into study designs, advancing personalized medicine and employing innovative technologies to better understand genotypes and phenotypes involved in pain perception and sleep characteristics, and manage the interplay between sleep and orofacial pain. The goal of addressing the interaction between sleep and pain is to improve health equity and optimize outcomes for individuals affected by these interrelated conditions.