A new study was published last week looking at the effectiveness of oral appliances in treating mild to moderate sleep apnea. The study actually showed that oral appliances were good at treating sleep apnea, but that’s not the story that many media outlets are promoting.
So let’s take a moment to look at what this study does and does not show.
The Study and Its Results
The study was intended to determine whether a prescription, adjustable oral appliance was capable of controlling daytime sleepiness and snoring in patients with sleep apnea. To prove this, researchers looked at 96 patients who had a n apnea-hypopnea index (AHI) under 30. These patients were assigned to either a treatment group or a placebo group where they received a fake device which looked similar but wasn’t designed to advance their jaw at all.
Researchers then measured the impact of treatment (or fake treatment) after four months. Initial and final values were compared for a number of sleepiness questionnaires. AHI measurements were taken with and without devices.
The study showed that for none of the various sleep questionnaires did people show a reduction in daytime sleepiness. However, the study did show that patients saw a major reduction in snoring and in symptoms of restless leg syndrome. And, most importantly, the study showed a significant reduction in AHI using the oral appliance. People were 7.8 times more likely to have their AHI reduced below five (the point at which you are not considered to have sleep apnea) with the oral appliance vs. the placebo.
Problems with the Study
In addition to the sense that it is wrong to say that the study showed oral appliances didn’t work, we have to point to some problems with the study. First, measuring sleep apnea with questionnaires is always dubious. As another recent study has shown, questionnaires may not be good ways to detect whether a person has sleep apnea.
Second, the size of the study is marginal for the conclusions they’re trying to make. Just 96 people is not an inadequate sample size for some things, but it’s too small to say that oral appliances don’t impact daytime sleepiness.
And then there’s the question about the way the study was run. We had to read the abstract a few times to realize that people were only being treated for four months because the study ran from May 2007 through August 2011. Why did it take four years to collect less than a hundred subjects? And then why did it take almost another four years to analyze the data? It’s very hard to maintain consistency and data tracking over an 8-year period.
We know that oral appliances are an effective treatment for sleep apnea. If you would like to learn how they can help you with your sleep apnea, please call (402) 493-4175 for an appointment with an Omaha sleep dentist at the Advanced Dental Sleep Treatment Center.