Sleep Apnea

Sleep apnea is a sleep disorder characterized by pauses in breathing during sleep. Episodes, called apneas, last long enough so that one or more breaths are missed, and occur repeatedly throughout sleep.

The standard definition of any apneic event includes a minimum 10 second interval between breaths, with either a neurological arousal (a 3-second or greater shift in EEG frequency), a blood oxygen desaturation of 3-4% or greater, or both arousal and desaturation. Sleep apnea is diagnosed with an overnight sleep test called a polysomnogram.

Obstructive sleep apnea (OSA) is the most common category of sleep-disordered breathing. The muscle tone of the body ordinarily relaxes during sleep. And since, at the level of the throat, the human airway is composed of walls of soft tissue . which can collapse . it is easy to understand why breathing can become obstructed during sleep. Mild, occasional sleep apnea, such as many people experience during an upper respiratory infection, may not be important. However, chronic, severe obstructive sleep apnea requires treatment to prevent sleep deprivation and other complications. The most serious complication is a severe form of congestive heart failure called cor pulmonale.

The most common treatment and arguably the most consistently effective treatment for sleep apnea is the use of a continous positive airway pressure (CPAP) device, which 'splints' the patient's airway open during sleep by means of a flow of pressurized air into the throat.

In addition to CPAP, a dentist specializing in sleep disorders can prescribe oral appliance therapy (OAT). The oral appliance is a custom-made mouthpiece that shifts the lower jaw forward, which opens up the airway. OAT is usually successful in patients with mild to moderate obstructive sleep apnea. OAT is a relatively new treatment option for sleep apnea in the United States, but is much more common in Canada and Europe.

CPAP and OAT are effective only for obstructive sleep apnea, not for central or mixed cases.

Snoring is the vibration of respiratory structures and the resulting sound, due to obstructed air movement during breathing while sleeping. In some cases, the sound may be soft, in others loud and unpleasant. The structures are usually the uvula and soft palate. The irregular airflow is caused by a blockage . and usually due to one of the following:

• Throat weakness, causing the throat to close during sleep
• Mis-positioned jaw, often caused by tension in the muscles
• Fat gathering in and around the throat (often associated with overweight or obesity)
• Obstruction in the nasal passageway

Statistics on snoring are often contradictory. However, at least 30% of adults, and perhaps as many as 50% of people in some demographics do snore.

Specially made dental appliances called mandibular advancement splints, are a common mode of treatment for snoring. They advance the lower jaw slightly, and thereby pull the tongue forward. Typically, a dentist specializing in sleep apnea dentistry is consulted. Such appliances have been proven to be effective in reducing snoring and sleep apnea in cases where the apnea is mild to moderate. Mandibular advancement splints are often tolerated much better than CPAP machines. Possible but rare side effects include gradual movement of the teeth, temporomandibular joint disorder, excess salivation, and gum irritation.