In his letter to the editor in this issue, Dr. Masi1 expresses concern that on one hand we plead for recognition and counting of all respiratory events for diagnosing OSA but on the other hand, we should “not worry” about complete elimination of events when utilizing an oral appliance. Some of the “paradox” relates to the difference between diagnosis and treatment. Patients typically come to us because of a complaint (e.g., sleepiness, poor sleep). We need to make sure we are doing what we can to give them an accurate diagnosis (within the confines of a disordered breathing index) and then prescribe appropriate treatment. The larger the net, the more flexibility we have in deciding appropriate treatment. Similarly, when treating, we would also like to provide maximum benefit, if possible. We try to titrate CPAP to eliminate disordered breathing events and snoring, and ideally, this should be true for a dental appliance. I am sure the authors of the OA paper and all dentists and sleep physicians alike, would be much happier if OA's eliminated every disordered breathing event and snoring; however, that is not the case (nor is it the case for CPAP). But “less than perfection” that is acceptable with OA's is still better than no treatment at all.
I like the concept put forth by Vanderveken et al.2 of “mean disease alleviation (MDA)” as a measure of overall therapeutic effectiveness using the product of adjusted compliance and device efficacy, divided by 100 and expressed as a percentage. For example, if a patient used their CPAP 4 hours out of 8 hours slept (50%), and it reduced their AHI from 100 to 10 (90%), their MDA would be 45%. If the same patient had an OA that they used 7/8 hours (87.5%) per night, and it reduced their AHI from 100 to 20 (80%), their MDA would be 70%. Ideally we should want to achieve elimination of all events but in reality “less than perfection” is the best we can achieve given the limitations of our treatment.
Dr. Collop has indicated no financial conflicts of interest.
Collop N. The “paradox” issue. J Clin Sleep Med 2014;10(6):705.
Masi AM, author. The lumpers and splitters paradox. J Clin Sleep Med. 2014;10:701.
Vanderveken OM, Dieltjens M, Wouters K, et al., authors. Objective measurement of compliance during oral appliance therapy for sleep disordered breathing. Thorax. 2013;68:91–6. [PubMed Central][PubMed]