Health Outcomes of Continuous Positive Airway Pressure Versus Oral Appliance Treatment for Obstructive Sleep Apnea: A Randomized Controlled Trial

Study Questions:

Are there similar health care effects after 1 month of optimal continuous positive airway pressure (CPAP) and mandibular advancement device (MAD) therapy?


This was a randomized crossover trial comparing optimal CPAP and MAD therapy in moderate to severe obstructive sleep apnea (OSA). Patients were excluded for central sleep apnea, pre-existing lung disease, periodontal disease, or insufficient dentition. Optimal therapy was defined as attaining the highest compliance with each treatment. Health effects measured after 1 month of therapy included: 24-hour blood pressure, neurobehavioral, and quality of life. Patients were randomized to the order of first therapy followed by a 2-week washout period between therapies.


A total of 177 patients were assessed, and following screening, 126 were randomized. The dropout rate was 15%, leaving 108 patients completing the study. The study sample consisted of 81% men with an average age of 49 ± 11 years. The mean apnea/hypopnea index (AHI) was 26 ± 12 events per hour, with 82% meeting criteria for moderate or severe OSA. CPAP was more efficacious than MAD in reducing AHI (CPAP AHI, 4.5 ± 6.6/hour; MAD AHI, 11.1 ± 12.1/hour; p < 0.01), but reported compliance was higher on MAD (MAD, 6.50 ± 1.3 hours per night vs. CPAP, 5.20 ± 2 hours per night; p < 0.00001). The 24-hour mean arterial pressure was not inferior on treatment with MAD compared with CPAP (CPAP-MAD difference, 0.2 mm Hg [95% confidence interval, -0.7 to 1.1]); however, overall, neither treatment improved blood pressure. In contrast, sleepiness and disease-specific quality of life improved on both treatments by similar amounts, although MAD was superior to CPAP for improving four general quality-of-life domains.


The authors concluded that health outcomes were similar after 1 month of optimal MAD and CPAP treatment in patients with moderate to severe OSA. Neither treatment seemed to improve blood pressure from baseline, likely related to the normotensive status of most participants.


This is the largest randomized trial comparing two forms of therapy for OSA. Although CPAP demonstrated superior efficacy in terms of AHI reduction, self-reported compliance with MAD was higher. Treatment preference results showed that 55 patients (51%) preferred MAD; 25 (23.1%) preferred CPAP; 23 (21.3%) preferred either; and 5 (4.6%) preferred neither. The results may be explained by greater efficacy of CPAP being offset by inferior compliance relative to MAD, resulting in similar effectiveness. These findings challenge the present thinking that MAD therapy should only be recommended to patients with mild OSA or those who have failed CPAP. This study provides rationale for a long-term comparative effectiveness study of these two therapies.

Clinical Topics: Heart Failure and Cardiomyopathies, Sleep Apnea

Keywords: Periodontal Diseases, Blood Pressure, Orthodontic Appliances, Removable, Sleep Apnea Syndromes, Dentition, Quality of Life, Cardiology, Continuous Positive Airway Pressure, Sleep Apnea, Central, Mandibular Advancement, Confidence Intervals, Sleep Apnea, Obstructive, Lung Diseases

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