• • Provision of signed and dated informed consent form

‣ Unable to tolerate or decline positive airway pressure therapy

⁃ Absence of markedly enlarged tonsils, defined as 3+ or 4+ according to the Brodsky classification

⁃ Able to protrude tongue ≥20mm beyond maxillary incisors

⁃ No uncontrolled nasal obstruction (must be able to breathe through nose)

⁃ Stable medication regimen for ≥1 month

⁃ Stated willingness to comply with all study procedures and availability for the duration of the study

⁃ Male or female, of any race, aged 18-70 years (inclusive)

⁃ If diagnosed with uncomplicated Mild to moderate, moderate to severe OSA (i.e., AHI \>5, \<30 h-1); where uncomplicated is defined by the absence of:

• Conditions that place the patient at increased risk of non-obstructive sleep-disordered breathing (e.g., central sleep apnea, hypoventilation, and sleep-related hypoxemia). Examples of such conditions include significant cardiopulmonary disease, potential respiratory muscles weakness due to neuromuscular conditions, history of stroke, and chronic opiate medication use.

∙ Concern for significant non-respiratory sleep disorder(s) that require evaluation (e.g., disorders of central hypersomnolence, parasomnias, sleep-related movement disorders) or interfere with accuracy of HSAT (e.g., severe insomnia).

∙ Environmental or personal factors that preclude the adequate acquisition and interpretation of data from HSAT.

⁃ Body mass index (BMI) \< 35 kg/m2

⁃ Neck circumference \< 45 cm

⁃ Absence of severe oxyhemoglobin desaturation during sleep, indicated by mean nocturnal SpO2 \> 82%

⁃ Mandibular range of motion \> 5 mm in protrusive direction

⁃ Adequate dentition, as determined by the site dentist

⁃ Must have a smart phone able to download 02 ring app