Dental Sleep Medicine
The importance of sleep medicine in dental education and practice
Snoring is a common form of sleep-disordered breathing caused by a narrowing and collapsing of the upper airway during sleep. When air flowing between the tongue and soft palate causes the soft palate to vibrate, noise is produced. Snoring is also a common symptom of obstructive sleep apnea (OSA), in which the obstruction is so significant it causes the sleeping individual to stop breathing frequently. The prevalence of OSA has been increasing, with 17% of 50- to 70-year-old men currently estimated to have moderately to severely disordered breathing during sleep.1
Both snoring and OSA have a wide variety of negative effects on health.2 Adverse outcomes that have been associated with untreated OSA include hypertension, coronary artery disease, stroke, atrial fibrillation, congestive heart failure, daytime sleepiness, and increased mortality.3 The condition also has been associated with a higher incidence of motor vehicle accidents. Negative social consequences accompany both snoring and OSA, as they disrupt the sleep of bed partners, whose own risk for cardiovascular disease, in turn, may increase.4
Treatment for Snoring and OSA
The most common approach to treating OSA is the use of continuous positive airway pressure (CPAP). First introduced in 1981,5 this is still the standard of care for OSA.6 However, CPAP machines are obtrusive, and compliance by patients often is suboptimal.7,8
As an alternative, the first oral appliance for OSA was developed in the 1980s. Since then, the Food and Drug Administration (FDA) has cleared more than 100 appliances for the treatment of snoring and OSA.9 Advantages of these devices include the fact that they are less cumbersome and more portable. Some patients tolerate them well, and their effectiveness in treating snoring and OSA has been demonstrated.10 Over time, their clinical use has increased substantially, along with the scientific literature evaluating them.
An oral appliance is a mandibular advancement device that repositions and stabilizes the mandible, while also typically engaging the maxilla.11 Use of this type of device has been found to be effective in the treatment of snoring and OSA.10 According to the American Academy of Dental Sleep Medicine (AADSM), an effective oral appliance is custom-fabricated using digital or physical impressions and models and is not a primarily prefabricated item that is trimmed, bent, relined, or otherwise modified. Oral appliances may or may not be adjustable, incorporating a mechanism to enable changing the position of the mandible over time. Also available to consumers are non-custom “boil and bite” devices, which are primarily prefabricated and usually partially modified to an individual patient’s oral structures. However, custom, titratable appliances are recommended for the treatment of OSA over non-custom devices.12 Another type of device is the tongue retention device, which seeks to keep the airway unobstructed during sleep by holding the tongue forward. Evidence also shows that these devices are usually not as effective as custom, titratable oral appliances due to poor compliance.13
Sleep Medicine and Dentistry
The similarity between the oral appliances used to treat OSA and other appliances commonly fabricated by dentists is one reason that interest in sleep medicine has grown within dental offices. Beyond that, dentists are the perfect care providers to become involved with sleep medicine “because we have a lot of interaction with our patients,” says Gary Radz, DDS, a Denver dentist and associate clinical professor at the University of Colorado School of Dentistry. He got involved with dental sleep medicine approximately 10 years ago because of his own problems with OSA. “Some of what you look for are potential anatomic problems associated with the airway and the back of the throat, things that we see all the time.”
Patients who have difficulty breathing when they’re tipped too far back in the dental chair are likely to have breathing disorders during sleep, as are those who are significantly obese. Other signs of OSA include heavy bruxism, gastroesophageal reflux disease (GERD), and higher Mallampati classifications. Bruxism is a sign because individuals who are experiencing apneic episodes often clench and/or grind the teeth in order to awaken and resume breathing. Acid reflux or GERD is another common symptom because when breathing becomes obstructed and the throat and windpipe muscles tighten, stomach acid may be pushed into the throat and mouth. A Class 3 or Class 4 Mallampati classification is relevant because those classifications indicate the most limited airway openings.
“We see the typical patient twice a year,” Radz notes. “We’ve got a fairly consistent and ongoing health care relationship with those people. It becomes very easy to bring up the subject because for us it’s part of the medical history information that we gather.” Administration of the STOP-BANG Sleep Apnea Questionnaire,14 which measures risk factors for sleep apnea, and the Epworth Sleepiness Scale questionnaire can help confirm a high risk for sleep-disordered breathing.
If that appears to be the case, dentists in some states can send patients home with a sleep-testing unit, a small box that typically records airflow, respiratory effort, brain waves, oxygen levels, and heart rate. The results are then interpreted by a board-certified sleep medicine physician. This data and interpretation provide the foundation for a diagnostic decision by a physician, the only care provider who can legally make a diagnosis. Alternatively, the dentist may refer the patient to a board-certified sleep medicine physician for a comprehensive sleep evaluation, which may involve either a home sleep apnea test or an overnight sleep study in a sleep center. Called a “polysomnogram,” a sleep study involves attaching electrodes to the patient’s body to record brain waves, heart rates, eye and leg movements, and other factors.