Sleep Apnea: Mixed Results for Mandibular Appliance

Beth Skwarecki

June 05, 2015

Mandibular advancement devices improved the number of apneas and hypopneas, but did not improve daytime sleepiness or quality of life, compared with placebo in a single-blind randomized study of patients with snoring or mild to moderate obstructive sleep apnea.

Marie Marklund, PhD, DDS, from the Department of Odontology, Faculty of Medicine, Umeå University, Sweden, and colleagues, report their findings online June 1 in JAMA Internal Medicine.

"Continuous positive airway pressure is a highly effective treatment for patients with daytime sleepiness and sleep apnea, but adherence problems as a result of nasal stuffiness, claustrophobia, and the risk of disturbing bed partners limit the overall usefulness of this therapy," the researchers write. However, it is unclear from prior studies whether a mandibular appliance will provide the same symptomatic relief.

Therefore, the investigators enrolled 96 patients with daytime sleepiness and an apnea-hypopnea index lower than 30. Patients were between ages 20 and 70 years, with a body mass index lower than 35 kg/m2, and had been referred by pulmonologists to be fitted with an appliance.

The mandibular device connected the upper and lower jaw with a screw for adjustment. Patients' mandibles were moved forward as tolerated, with a mean adjustment of 6.8 mm (standard deviation, 1.1). The placebo was a splint worn only on the upper jaw. Compliance was not significantly different between the two groups, with participants wearing the active device on 89% of nights, and those in the placebo group using it 83% of nights.

After 4 months, patients wearing the active device had less snoring than those wearing the placebo (P < .001). Apnea improved, with an apnea-hypopnea index lower than 5 in 49% of patients using the appliance and 11% of patients using the placebo (P = .001), with an odds ratio of 7.8 (95% confidence interval, 2.6 - 23.5) and a number needed to treat of 3.

However, there was no difference between groups in daytime sleepiness, quality-of-life measures, or other sleep parameters, including total sleep time, sleep efficiency, or sleep stages. Adverse effects were more common with the device than placebo, including jaw pain (P = .004), tooth pain (P = .02), hypersalivation (P = .03), and bite changes (P < .001).

The study "illustrates the difficulty of determining the effect of this device on patients' quality of life," Winfried Randerath, MD, from the Clinic of Pneumology and Allergology Center for Sleep Medicine and Respiratory Care at Bethanien Hospital in Solingen, Germany, writes in an invited commentary.

Most of the patients in the oral appliance group (89%) wanted to keep using the appliance after the study ended. Even participants using a placebo device reported subjective improvements, and 52% were interested in continuing to use the placebo device after the study ended.

The "huge variety" in mandibular advancement devices makes it difficult to generalize the results of studies like this one, according to Dr Randerath, because differences in the design may affect compliance and adverse effects, as well as effectiveness.

Whether patients should use a mandibular appliance instead of a continuous positive airway pressure machine is not clear from this study or from previous ones, Dr Randerath writes, and trials comparing the two are needed. Continuous positive airway pressure devices improve some cardiovascular parameters, and it is not clear whether mandibular devices could do the same.

Severe obstructive sleep apnea should still be treated with continuous positive airway pressure, the investigators and Dr Randerath agree, but Dr Randerath writes that snoring and mild obstructive sleep apnea may not need to be treated at all. That leaves the question of whether mandibular devices are an appropriate treatment for patients with mild or moderate obstructive sleep apnea.

The authors have disclosed no relevant financial relationships. Dr Randerath has received fees for speaking and research funds from companies producing positive airway pressure devices (Weinmann, Respironics, Resmed, and Heinen + Löwenstein).

JAMA Intern Med. Published online June 1, 2015. Abstract


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