Patients with mild to moderate obstructive sleep apnea (OSA) may consider adjustable oral appliances (OAs), devices that fit within the mouth to prevent upper airway collapse, as an effective first-line treatment, according to two studies conducted by sleep medicine specialists from Walter Reed National Military Medical Center (WRNMMC) in Bethesda, Md.
The retrospective, peer-reviewed studies, published in the December 2011 issue of CHEST and in the current issue of the Journal of Clinical Sleep Medicine (JCSM), provide findings on OAs from the largest patient populations studied to date.The studies found that adjustable OAs are nearly as effective as continuous positive airway pressure (CPAP) treatment for patients with a mild form of OSA and are more effective than fixed oral appliances, particularly in patients with moderate to severe OSA.
"Historically, CPAP has been the primary treatment for OSA, but only half of patients tolerate this therapy, which requires wearing a face mask hooked to a machine each night," said Lt. Col. Christopher Lettieri, M.D., one of the studies' authors, an Army medical director and the chief of sleep medicine in the pulmonary, critical care and sleep medicine department at WRNMMC. "This new data offers a fresh look at adjustable oral appliances as an initial treatment for OSA in both the military and civilian sectors." Eighteen million Americans, or 4 percent of men and 2 percent of women, suffer from sleep apnea, which can cause daytime sleepiness and has been linked to high blood pressure, heart attack, and stroke.
The military is interested in the potential of adjustable OAs, also called mandibular advancement devices, as alternatives to CPAP systems since some active duty service members deploy to austere environments where electricity needed to run CPAP machines is not always available. In these cases, reliance on CPAP may result in duty restrictions or separation from service.
The study in CHEST, titled "Efficacy of an Adjustable Oral Appliance and Comparison to Continuous Positive Airway Pressure for the Treatment of Obstructive Sleep Apnea Syndrome," evaluated and compared results of overnight sleep studies in which patients used adjustable OAs or CPAP devices. Results were measured by the apnea-hypopnea index (AHI) score, used to assess the severity of sleep apnea based on the total number of complete cessations (apnea) and partial obstructions (hypoapnea) of breathing that last for at least 10 seconds per hour of sleep. Researchers found that a significantly higher percentage of patients using an adjustable OA experienced successful reduction of their AHI score to below five apneic events per hour in this study compared to past reports (62.3 percent versus 54 percent).
In the JCSM study, "Comparison of Adjustable and Fixed Oral Appliances for the Treatment of Obstructive Sleep Apnea," patients were treated with either adjustable or fixed OAs and a sleep evaluation was conducted before and during treatment with the devices. Patients using adjustable OAs had a greater reduction in obstructive events (AHI), revealing that adjustable OAs had a greater efficacy than fixed devices (57.2 percent vs. 46.9 percent) among this patient cohort.
A total of 497 patients were prescribed adjustable OAs in the CHEST study and 602 patients in the JCSM study. The studies included patients who participated in an overnight sleep study at the sleep disorders center at Walter Reed National Military Medical Center.
Article by Advance for Respiratory Care & Sleep Medicine
