Clinical relevance of circadian clocks within the orofacial scope of sleep medicine: Implications for diagnosis, therapeutic and prophylactic measures

Circadian clocks regulate sleep-wake patterns, metabolism, autonomic tone, and painperception. Their disruption contributes to multiple pathologies, including sleepdisorders and cardiovascular dysfunction. Within the orofacial domain, circadianrhythms influence the timing, intensity, and interaction of conditions such as insomnia,obstructive sleep apnea, sleep bruxism, orofacial pain and temporomandibulardisorders.This review outlines how circadian mechanisms and the orexinergic system provide anintegrative framework for understanding these orofacial sleep disorders and theirsystemic consequences. Circadian dysregulation can manifest as insomnia (e.g.,delayed or advanced phase), modulate apnea severity via time-dependent variations inairway tone and hypoxic response, and influence rhythmic masticatory activity throughorexinergic modulation of arousal and motor output. Recognizing these temporaldynamics allows refinement of diagnosis, therapy, and scheduling of dentalinterventions.Clinical strategies such as light therapy, melatonin supplementation, behavioralsynchronization, and timing of appointments may enhance treatment outcomes.Awareness of possible iatrogenic effects (e.g., evening dental light exposure) shouldalso guide practice. Integrating circadian and orofacial approaches may advanceprecision in dental sleep medicine and mitigate health related risks.