July 16, 2003 -- Untreated sleep apnea can result in dangerous daytime sleepiness, not to mention high blood pressure, heart attack, and stroke. Though an effective treatment is available, called continuous positive air pressure (CPAP), roughly half of patients find the CPAP masks to be too uncomfortable to use.
Compliance seems to be higher among patients treated with fitted dental devices that are put in place before going to bed, but the evidence that these mouth guard-like appliances actually work has been lacking, and exactly how they work remains unclear. Now, new research from Australia shows them to be effective for treating even severe obstructive sleep apnea.
Improved Symptoms, Sleep Patterns
In a series of studies, Peter A. Cistulli, MD, PhD, and colleagues from the University of New South Wales assessed one of several oral devices used in the treatment of obstructive sleep apnea. In an investigation involving 80 patients, two-thirds had significant improvement in nighttime sleep patterns while using the devices. In their latest research, published in the July issue of the American Journal of Respiratory and Critical Care Medicine, they report that the device works by preventing the upper airway from collapsing during sleep.
Obstructive sleep apnea results from airway blockage, which is usually caused by the collapse of the soft tissue in the rear of the throat during sleep. Risk factors include being male, overweight, and over the age of 40.
People with the condition may stop breathing hundreds of times each night, and breathing can be interrupted for a minute or more. Loud snoring and daytime sleepiness are the most common immediate symptoms.
CPAP works by forcing air into the nose, through either a fitted mask or nose prongs, to maintain an open airway passage. The most effective dental devices work by pushing the lower jaw forward, thereby opening the air passage behind the tongue. Most are custom made by dentists and are adjusted periodically to find the most comfortable and effective position for the individual patient.
The latest Australian study involved 10 patients with obstructive sleep apnea who were closely observed while wearing the custom-fitted devices for one week. The average number of obstructive events among the patients was reduced from 25 per night without the dental appliances to less than five with them.
Cistulli tells WebMD that the device appeared to be most effective in the treatment of patients with mild to moderate obstructive sleep apnea, but it has also been shown to work for many patients with severe apnea. Although his research team has not conducted compliance studies, he says most patients do not seem to have a problem sleeping with the devices on.
"CPAP is extremely effective, but studies show that many patients only use it for three or four hours a night," he says. "Our patients tell us that they are using these mouth devices all night. A partially effective treatment that is used more may be as good as a very effective treatment that is only used sporadically."
American Sleep Apnea Association spokeswoman Christin Englehardt says clinicians treating sleep apnea have been slow to recommend the dental devices because there have been so few studies assessing their effectiveness. But she adds that this may be changing.
"Oral appliance therapy is an accepted treatment for obstructive sleep apnea, but as with any treatment option many factors may determine its effectiveness, including the severity of the sleep disordered breathing and the individual patient's medical history," she says.