An oral appliance that advances a patient’s lower jaw reduced episodes of obstructive sleep apnea, snoring, and restless legs symptoms, according to a report published online June 1 in JAMA Internal Medicine.
The device, however, failed to improve daytime sleepiness or quality of life in a Swedish study of adults who had daytime sleepiness and either snoring or mild to moderate sleep apnea, said Marie Marklund, Ph.D., D.D.S., of the department of odontology at Umeå (Sweden) University and her associates (JAMA Intern. Med. 2015 June 1 [doi:10.1001/jamainternmed.2015.2051]).
Previous studies of oral appliances have focused on patients with more severe sleep apnea and have yielded conflicting results, particularly regarding daytime sleepiness.
A total of 91 patients who were randomly assigned to receive either a placebo device (46 patients) or an oral appliance individually made by a dental technician using separate plaster casts of the upper and lower teeth (45 participants) completed the study. The device’s elastomer pieces fitted over the teeth and were connected with a screw that allowed continuous gradual advancement of the lower jaw by 6-7 mm. Holding the lower mandible forward improves breathing during sleep.
After 4 months of follow-up, at-home overnight polysomnography showed “a clear, significant treatment effect”: the mean apnea-hypopnea index (AHI) was 6.7 in the active-treatment group, compared with 16.7 in the placebo group. A total of 49% of the patients receiving active treatment had an AHI lower than 5, compared with only 11% of those using the placebo device, for an odds ratio of 7.8 and a number needed to treat of 3.
Snoring and symptoms of restless legs also were significantly less frequent with the active treatment, Dr. Marklund and her associates said.
In addition, 73% of patients who used oral appliances said that their expectations of treatment were either “totally” or “sufficiently” fulfilled, compared with only 11% of those who used placebo devices. And 89% of patients who used oral appliances said they would continue the treatment after completing the study, compared with only 52% of those who used the sham device.
However, daytime sleepiness, measured subjectively using the Epworth Sleepiness Scale and the Karolinska Sleepiness Scale and measured objectively using the Oxford Sleep Resistance test, did not differ significantly between the two study groups. The number of days with headaches, the intensity of headaches, the presence of nasal congestion, difficulty falling asleep, nighttime awakenings, nightmares, and reaction times also were not significantly different, nor were scores on a quality of life measure.
The study was supported by grants from the Swedish Research Council, the Swedish Heart and Lung Foundation, and the County Council of Vasterbotten. Dr. Marklund and her associates reported no conflicts of interest.