Hypothesis ORCADES results suggest that Narval O.R.M CC could be more efficient than Narval MRD trad to reduce AHI whatever the initial OSA severity 79% of CC MRD patients have at least an AHI reduction of 50% (vs. 61% with a trad Narval MRD, p=0.0031) 66% of CC MRD patients get a complete answer with an AHI reduction <10 (vs. 49% with a trad Narval MRD, p=0.0017) The investigators think that differences seen in the ORCADES study between the 2 MRD is due to a different impact on upper airway volume