Mandibular Advancement Devices (MADs) are now a reliable alternative to continuous positive airway pressure (CPAP) treatments for Obstructive Sleep Apnea (OSA) . Despite good tolerance and efficacy, there are still barriers limiting the widespread use of MAD and its acceptance in OSA routine clinical practice. Various MAD designs currently exist and constantly emerge on the market without clear evidence regarding the best technical choice and the cost-effectiveness compromise. Although these MAD has been tested in term of efficacy, no study has tested the difference between MADs in term of efficacy, tolerance and patient satisfaction. The aim of this clinical trial is to compare the effectiveness of two MADs - custom-made titratable MAD (NarvalTM) and customizable titratable MAD (TALITM), over a 3-month period, in patients with obstructive sleep apnea (OSA).

Obstructive Sleep Apnea (OSA) is characterized by repetitive episodes of partial or complete pharyngeal obstruction during sleep. OSA is one of the most frequent chronic diseases with both social and multi-organ consequences making it an economic burden for society. OSA durably impairs the quality of life of patients and their entourage and is associated with co-morbidities including hypertension, arrhythmias, stroke, coronary heart disease and metabolic dysfunction.

Continuous positive airway pressure (CPAP), the first line therapy for OSA, requires high adherence to be effective in terms of symptom improvement and reduction of the burden of co-morbidities. For one third of patients, such adherence is difficult to achieve in the long term and mandibular advancement devices (MAD) have emerged as the leading alternative to CPAP. So, MADs are now a reliable alternative to CPAP treatments, which position these in numerous patients as a first therapy. Moreover, mild to moderate symptomatic patients who refuse to be diagnosed are now referring to sleep centers in order to be treated. MAD and CPAP are similarly effective on symptoms, quality of life and in attaining reductions in blood pressure and cardiovascular morbidity. Although CPAP has a greater effect on Apnea + hypopnea index (AHI) reduction, adherence is better with MAD explaining the comparable mean disease alleviation achieved by the two treatment modalities.

Despite good tolerance and efficacy, there are still barriers limiting the widespread use of MAD and its acceptance in OSA routine clinical practice. Various different MAD designs currently exist and constantly emerge on the market without clear evidence regarding the best technical choice and the cost-effectiveness compromise. Titratable two-piece custom-made MADs are the gold standard in clinical guidelines and several brands are now on the market. Although these MAD has been tested in term of efficacy, no study has tested the difference between MADs in term of efficacy, tolerance and patient satisfaction. Such a paradigm merits being tested in a randomized controlled trial. The SONAR study is a multicenter, parallel-group randomized controlled trial to determine if the titratable MAD NARVAL TM is superior to the titratable MAD TALITM in OSA patients eligible for MAD. The primary outcome will be the treatment response at 3 months assessed by the difference of delta AHI at baseline and follow-up measured by polysomnography and secondary outcomes focus at global efficacy, tolerance and patient satisfaction.

To our knowledge it will be the first study comparing two titrable MADs.

Inclusion Criteria:

1. Signed written informed consent before participation

2. Age ≥18 years

3. Moderate to severe OSA defined by:

   • AHI ≥30 or,
   • 15≤ AHI <30, but associated with excessive daytime sleepiness or,
   • 15≤ AHI <30, with at least two of the following criteria not explained by other factors: severe and daily snoring, choking or suffocating sensation during sleep, non-restorative sleep, daytime fatigue, difficulty concentrating, nocturia (more than one urination per night).

4. Naïve from any mandibular advancement device

5. Patient affiliated to a social security/health insurance system

Exclusion Criteria:

1. One or more of the following contra-indications:

   • dental problems (tooth failure, poor distribution or insufficient dental retention)
   • periodontal problems: active periodontitis not stabilized. Presence of periodontal pockets, advanced bone loss, significant tooth mobility, insufficient dental plaque control.
   • temporomandibular joint disorder (TJD)
   • maximum mandibular propulsion distance limited (< 6 mm)

2. More than 20% of central apnea and hypopnea

3. Severe psychiatric or neuromuscular disorder

4. Body Mass Index (BMI) > 30 kg/m2

5. Current orthodontic treatment or planned during the study

6. Pregnant women based on clinical exam and medical questioning.

7. Subject in exclusion period of another interventional study

8. Subject under administrative or judicial control

9. Subject unable to understand, follow objectives or methods due to cognition or language problems

open, multicenter study in 90 obstructive sleep apnea (OSA) patients