The OAMMM study is a mono-centrer , non interventional, prospective study, carried out in CH Valence

Oral Appliance is indicated for first line moderate sleep Apnea Syndrome or severe sleep Apnea Syndrome after failure of positive airway pressure (CPAP).

Clinical impact of each mm advancement of Oral Appliance is imperfectly assessed.

The study aim to assess clinical and paraclinical efficacy of an oral Appliance on each mm of advancement.

Oral appliance will be delivered with a propulsion at 50% of the maximum advance and the investigator will titrate the advance according to the usual method

Polygraphy and clinical effectiveness of the Oral appliance will be evaluate

Inclusion Criteria:

• Age ≥ 18 years old
• Moderate sleep apnea diagnosis with clinical signs
• Severe sleep apnea with failure continuous positive airway pressure( CPAP)

Exclusion Criteria:

• previous sleep apnea treatment for Moderate sleep apnea
• refusal to participate in research
• Patient under guardianship, deprived of liberty, safeguard of justice

adult patients, with primary Moderate sleep apnea or Severe sleep apnea with failure continuous positive airway pressure( CPAP).