Currently, mandibular advancement devices (MAD) are recommended by the American Academy of Sleep Medicine (AASM) as the first treatment a line in cases of mild and moderate OSAS in patients without severe cardiovascular comorbidity and in severe OSAS when treatment with CPAP fails or is rejected. Although oral appliances (OD) have less impact on AHI reduction, both treatments have been shown to have a similar impact on clinical outcomes, including symptomatology and cardiovascular outcomes. In addition, MAD is a treatment that is better tolerated by patients, which results in greater compliance on their part, and therefore a similar efficacy in clinical practice.

Its mechanism of action consists of maintaining the patency of the upper airway, preventing collapse. They act by correcting the anatomical imbalance of patients with OSAS, specifically stabilizing and increasing the space of the velopharyngeal airways, reducing their collapsibility.

However, the effectiveness of the treatment of this pathology using MAD is limited by the inter-individual preference of the results of the treatment and the lack of information in the correct selection of the appropriate patients. In fact, oral appliances are an effective treatment for 60-70% of patients. Therefore, the precise selection of patients is essential to optimize the results of MAD treatment and thus avoid the necessary costs. This justifies the need to identify phenotypes likely to predict response to MAD treatment.

Inclusion Criteria:

• Patients older than 18 years
• Adult patients with obstructive sleep apnea diagnosed according to the third edition of the International Classification of Sleep Disorders.
• Apnea-hypopnea index (AHI) of at least 5/hour of sleep.

Exclusion Criteria:

• Patients with heart disease.
• Central sleep apnea.
• Patients who had degenerative pathologies of the temporomandibular joint.
• Patients who had moderate or advanced periodontal disease.
• Pregnant patients.

Patients from the Master's Degree in Prosthodontics and Occlusion at the University of Valencia will be selected. At the dental clinic of the Lluis Alcanyis Foundation. Located in Gascó Oliag Nº 1, Valencia.