Effectiveness of an oral appliance is normally based on the action of moving the bottom jaw forward; they all work the same. A patient continuing with treatment is based on many things. Comfort is # 1 and the fit of the appliance is #2. Studies published as recently as December of last year show that half of the people who get an oral appliance stop using it in the first year...and these appliances were custom fitted by a dentist. Oral appliance therapy is not for everyone!!!! It works half as well as CPAP (but more patients use it all night) and has side effects. As to F.D.A. clearance, the FDA's job is to protect the public from dangerous therapies. All devices cleared (this includes the custom fitted devices use by Dr. Luisi) must be made of materials safe to be used in the mouth (no cancer producing materials, etc.) and must prove they are essentially equivalent to a device previously found to be safe for use. Even the custom made devices used by dentists do not have to 'prove' they work, only that they are safe. All devices have side-effects and very few studies show that one appliance is safer or more effective than another. Efficacy rates only apply to scientific studies and cannot be generalized to a real life situation. In one study an appliance my be effective in treating sleep apnea in 25 % of the patients and in another study as effective as 50%. Thus data must be analyzed for the quality of the study, the people being studied (were they all young or old or overweight) and then compared to the quality of other studies. People who do not understand evidence based medicine often believe that numbers from a single study are to be taken as a fact, not as an indication of a certain outcome.
Absolutely, Each efficacy study must be carefully evaluated as to the selection criteria for the patients, what is defined as success, the amount and time of follow-up, and many other things. It is a very complicated process. The efficacy rates WILL vary depending on how these factors line up. One of the big problems is that the different studies use so many different assumptions that the results can not be compared. Comparing Apples to Oranges. Never-the-less, it is clear that some appliances are more effective in real life than others. One study is not conclusive, but there are trends. Any experienced sleep dentist who sleep tests their appliances gets a feel for which appliances are doing better and there are differences. I am not going to name names, but I have had repeated instances in my practice where patients came in with certain appliances that have not tested well in their sleep studies with oral appliance in place and then I have substituted another design and the new sleep study with oral appliance in place shows good results. My real point is that we can do better than this. Efficacy testing needs to be standardized with the same assumptions for each test so that the results can be compared. Probably, the tests need to be administered by one agency for uniformity, possibly the F.D.A.. More research needs to be done into the effects of different designs with respect to efficacy. My sense of it is, with more research, we can offer oral appliances that are uniformly more effective for the patients and break the "50%" barrier. At least that is my hope. Arthur B. Luisi, Jr.,D.M.D.
It is true that all mandibular advancement devices ultimately work by advancing the mandible, but in terms of efficacy, the devil is in the details, for instance, some devices have very coarse strap adjustments and a relatively limited range of adjustability and these tend to be less effective than devices with fine adjustment mechanisms and a much wider range of protrusive movement. Many appliances are designed to allow free opening and closing of the mouth in the name of comfort, but it is widely recognized by experienced sleep dentists and some manufacturers that appliances that keep the mouth from falling open have better rates of efficacy than the ones that allow the mouth to fall open even though they both can produce the same amount of mandibular protrusion(I have a good study to support this and will submit it when I locate it in my records). These things matter and patients have the right to know about the differences and that all appliances are not "essentially" the same. Again, more research needs to be done on these things. Arthur B. Luisi, Jr.,D.M.D.
The study quoted in my last post is as follows: A Method of Studying Adaptive Changes of the Oropharynx to Variation in Mandibular Position in Patients With Obstructive Sleep Apnea. J. Oral Rehabil. 1996 Oct.23(10):699-711. Test: 6 subjects moved their mandibles to maximum protrusive position. Then fluoroscopic imaging was done as the subjects opened their mandibles in maximum protrusive position. Jaw opening resulted in synchronous posterior movement of both tongue and soft palate, with subsequent narrowing of oropharyngeal airspace. Recommendation: It is suggested that, where artificial mandibular advancement with dental devices is considered beneficial, jaw OPENING should be kept to a minimum. The point that I am making is that a large number of the MADs on the market, perhaps a majority, Do allow the mandible to fall open in the name of "comfort", this will cause a significant loss of efficacy that both the prescribing dentists and the patients are not informed is going to happen. All MADs are NOT created equal. Arthur B. Luisi, Jr., D.M.D.