The last fifty years have seen amazing advances in the study of neurophysiology of sleep and circadian biology. Circadian refers the biological mechanisms that repeat naturally on a twenty-four cycle. The genes that regulate these circadian rhythms have been isolated. Additionally, interactions between sleep and almost all other body systems (cardiovascular, respiratory, neurologic and endocrine) have become a center of attention for research. These scientific advances have originated from diverse clinical disciplines, including:
- Otorhinolaryngology (ear,nose,throat)
- Internal medicine
- Pediatric medicine
The variety in specialties reflects the interdisciplinary nature of sleep and its disorders. It must also be noted that many critical contributions have also come from the field of dentistry. Certain disorders, including sleep bruxism, sleep apnea, and chronic pain have a direct bearing on clinical dentistry. Thus, dentist should have a working understanding of sleep biology (somnology) and sleep pathology (sleep medicine).
Sleep disorders diminish the quality of sleep by breaking its continuity. Sleep disorder also generate a physiologic response that tends to push a sleeping person to a sublevel of wakefulness. While the person sleeping is unaware, their brain and autonomic nervous system are under a state of transient arousal. It is typical to observe brief arousals during sleep. However, when these are too frequent or too long, they can cause memory problems, mood alterations, health problems, and performance deficiencies in healthy people after only a few days. Disordered breathing during sleep can cause severe variation to a patients’ daytime vigilance, resulting in an increased risk of transport- or work-related accidents. Drowsy driving is a dangerous problem. In the long term, sleep apnea is known to be a serious factor for heart failure, stroke, kidney failure, congestive heart failure, hypertension and diabetes. The imposition of snoring and tooth-grinding sounds are also a major cause of sleep disruption for the person’ bed partner and can be a source of marital conflict.
Orofacial pain (any pain which is felt in the mouth, jaws and the face) can be connected with delayed sleep onset and disturbed sleep continuity. Thus, it is a major cause of insomnia that may predispose patients to depression and mood alteration. Poor sleep is known to lessen pain processing and can directly contribute to pain enhancement. Hence, the prevention and management of sleep disorders should become a normal component of the treatment plan for chronic orofacial pain-related conditions.
Sleep medicine is often an ignored part of public health. In many countries, access to sleep medicine is a major public health problem. In countries where therapy is offered, treating sleep disturbances either as primary disorders or as comorbidities with other medical, dental, or psychiatric conditions is a substantial opportunity to improve and prevent medical and psychiatric morbidity. It can also lessen the considerable financial burden related to the direct and indirect consequences of disturbed sleep.
Dentists must play an important role in sleep medicine by examining patients (physical exam and screening questions) during their annual or biannual dental checkup for risk of sleep-disordered breathing.
Patients need to be guided by dentists to seek further evaluation for the possibility of sleep disorder breathing is the following sign or symptoms are reveled at their dental exam:
- Daytime sleepiness
- Morning headaches
- Unrefreshed sleep
- Large tonsils
- Scalloped tongue
- Deep palate
- Large tongue
To take care of the tooth damage, sound and pain caused by bruxism, oral appliances can be used. The dentist needs to recognize when such as appliance is indicated and the risks associated with its use.
When patients complain of morning headaches and temporomandibular disorders (TMDs), the elimination of breathing disorders is a crucial decision that is usually made in a collaboration with the sleep medicine specialist, pulmonologist, neurologist, internal medicine physician and psychiatrist. Dentist should refer patients who experience sleep bruxism in combination with TMD for sleep testing. Especially when patients also complain of significant insomnia or poor sleep. More and more data suggests that both sleep bruxism and TMDs (which often occur in females of normal weight) are associated with increased risk for sleep apnea disorder breathing.
Dentists caring for patients with chronic orofacial pain conditions also need to appreciate basic sleep hygiene principles and to know when to refer patients with intractable or chronic insomnia for sleep medicine evaluation. Behavioral treatments for intractable or chronic insomnia are considered first-line interventions over pharmacologic treatment options. Also, a subset of chronic orofacial pain patients present with a complex psychologic overlay that adds to their ongoing pain and disability. The combination of pain and disability can be managed by sleep psychologists working in conjunction with the interdisciplinary team.
Dental sleep medicine is fast evolving field of preventive medicine. However, there remains a shortage of well-trained dental sleep medicine doctors. Both physicians and dentists can help improve the health and well-being of the estimated 20% of the population suffering from sleep disorders.