Oral Appliances vs. CPAP


Although CPAP remains the gold standard of obstructive sleep apnea therapy,  most studies cite a CPAP non-compliance rate around 50% - and the vast majority of these patients simply fall through the cracks, unaware of other treatment options or how to pursue them.

Designed specifically to address this massive treatment need (there are currently about 30 million US adults with sleep apnea), an oral appliance is a retainer-like dental device that is worn only during sleep in order to support the jaw in a forward position and maintain an open upper airway. 


Current AASM and Medicare guidelines recommend that physicians prescribe Oral Appliance Therapy to Mild or Moderate Obstructive Sleep Apnea patients who prefer OA to CPAP, or who fail treatment attempts with CPAP; and to severe OSA patients who have already attempted CPAP therapy but could not tolerate it.

In contrast with CPAP, where only 50% of patients use the device > 4hr/ night, 70% of the nights (a number which drops to 17% of patients at 5 years), numerous studies show that oral appliance is preferred by patients over CPAP therapy and that usage remains at > 6 hrs per night for a median of 77% of nights (Sutherland et al.  J Dental Sleep Med 2015).  Since > 5.6 hr of CPAP use is needed to sustain a long-term reduction in blood pressure and cardiovascular mortality risk, there has been increasing interest in the use of oral appliance therapy and the concept of Mean Disease Alleviation, which includes both the efficacy and compliance rate in the estimation of a treatment modality’s overall effectiveness.  Multiple studies conducted to compare the effectiveness of CPAP and oral appliance therapy (OAT) have shown that while CPAP is somewhat more effective at reducing AHI and hypoxemia,  the two treatments result in equivalent outcomes  over a broad range of clinical parameters, including daytime sleepiness, cognitive performance, simulated driving performance, blood pressure reduction and endothelial dysfunction, as well as the incidence of fatal cardiovascular events in severe OSA (Sutherland et al. J Clin Sleep Med 2014, Sutherland et al.  J of Dental Sleep Medicine 2015, Phillips et al Am J Resp Crit Care Med 2103).  At the same time, it is worth noting that recent protocol improvements that utilize objective HST titration to find the optimal oral appliance setting are demonstrating reductions in AHI equivalent to CPAP, with 85% success rates in mild and moderate OSA in randomized, placebo-controlled trials (Vanderveken et al., Respiration 2011; 81:411-419).


Recent studies also show that approximately 70% of patients who failed CPAP can tolerate Combination Therapy – a treatment approach where nasal pillows can be attached directly to the oral appliance, without the need for headgear and at significantly lower pressures, eliminating many of the patient objections associated with CPAP.  This has allowed us to rescue many high-risk patients who failed CPAP, reducing their chance of stroke, heart attack and other serious comorbidities.   In high-risk patients with severe OSA and/or significant cardiovascular disease burden, we also recommend that Combination Therapy be used as a safer transition to Oral Appliance treatment during the 2-3 months typically required for advancements and repeat titration/efficacy HST studies.


We strongly encourage patients with severe sleep apnea or very significant cardiovascular risks to try CPAP first or talk to us about Combination Therapy, which has been shown to make the CPAP treatment much easier to tolerate and can rescue many failing CPAP cases.


What Is Oral Appliance Therapy (OAT)?

The American Academy of Sleep Medicine endorses  Oral Appliance Therapy as a  treatment  alternative to CPAP for patients with snoring and sleep apnea, if patients prefer an oral appliance  or are not able to tolerate CPAP.

Please note that a proper OAT protocol requires direct consultation with a physician, a diagnostic sleep study ordered by a sleep physician or other medical provider, a written prescription from the patient's physician and, always, a follow-up sleep study to objectively demonstrate the efficacy of the appliance and identify the optimal setting on the device. Subjective reports of better sleep or lack of snoring, by themselves,  do not represent sufficient proof of treatment efficacy in a patient with a diagnosis of sleep apnea. 

Source:   Ramar K, Dort LC, Katz SG, Lettieri CJ, Harrod CG, Thomas SM, Chervin RD. Clinical practice guideline for the treatment of obstructive sleep apnea and snoring with oral appliance therapy: an update for 2015. Journal of Dental Sleep Medicine 2015;2(3):71– 125.


How Does the Effectiveness of Oral Appliance Therapy Compare to CPAP? 

“Despite discrepancies in efficacy (apnea-hypopnea index [AHI] reduction) between CPAP and oral appliances, randomized trials show similar improvements in health outcomes between treatments, including sleepiness, quality of life, driving performance, and blood pressure.” 

“Adequate CPAP compliance, based on reported average usage rates, is generally accepted as > 4 h on ≥ 70% if nights. However, even with strategies to enhance patient acceptance and usage, only 50% of patients use CPAP ≥ 4 h per night after 6 months. The proportion of patients maintaining this minimally acceptable level of CPAP usage further drops to 17% after 5 years. Furthermore this 4-h threshold is arbitrary and not necessarily adequate to convey benefits for all important health outcomes. […] For example, normalization of subjective sleepiness (ESS), objective sleepiness (multiple sleep latency test), and disease specific functional status (functional outcomes of sleep questionnaire [FOSQ]) requires 4, 6, and 7.5 h, respectively, of nightly CPAP usage. In hypertensive OSA patients, ≥ 5.6 h of CPAP usage is required to sustain a long-term reduction in blood pressure. CPAP usage > 6 h per night shows greatest reduction in mortality risk. 

“A likely explanation for similarity in key health outcomes is that oral appliances are more consistently used for a greater proportion of the total sleep period, compared to CPAP. […]. Oral appliances were preferred to CPAP in four of six crossover trials asking for treatment preference at the end of the trial.

Similar results in terms of health outcomes suggests that although the two treatments have different efficacy and treatment usage profiles, these result in similar overall effectiveness.

Source:  Sutherland K, Phillips CL, Cistulli PA. Efficacy versus effectiveness in the treatment of obstructive sleep apnea: CPAP and oral appliances. Journal of Dental Sleep Medicine 2015;2(4)