Obstructive Sleep Apnea Non-PAP Outcomes and Viable Alternatives

Inclusion Criteria: * Must consent to being a part of the study * Must be willing and able to physically present to the our office site on the Hospital campus whenever necessary over the course of the study * Able to read, write, speak, and understand English * Willing to complete study surveys over the course of the study. * Must have a diagnosis for moderate to severe OSA (AHI ≥15) with indications for PAP therapy OSA is stratified into mild (5 ≤ AHI ≤ 15), moderate (15 \< AHI ≤ 30), and severe (AHI\>30) * Must have declined PAP therapy (unwillingness to use), failed PAP therapy (AHI \> 15 on PAP), or are inadherent to PAP therapy (not using PAP ≥4 hours/night for ≥5 nights per week, also defined as intolerance to PAP) * Age ≥ 18 years * BMI ≤ 40 kg/m² * Central/Mixed apneas contribute \< 25% of AHI (Predominantly Obstructive Sleep Apnea) * Willing to complete pre-intervention and post-intervention sleep studies * Planning to obtain MAD or HGNS as part of clinical care Exclusion Criteria: * AHI \> 65 o The guidelines for HGNS usage were originally approved for an AHI upper limit of 65. We will not enroll anyone in the study with an AHI greater than 65. * Dental conditions such as temporomandibular joint disease, periodontal disease, dental disease, insufficient dentition (edentulism) to support appliance retention, and inadequate range of motion of the jaw. Similarly, patients undergoing dental realignment (e.g., braces or retaining device) are not suitable candidates. * Chronic nasal obstruction * Individuals without manual dexterity to place and remove the device such as those afflicted with severe arthritis, or neuromuscular disease that affects dexterity. * Prior intolerance to MAD * Rapid therapy required: patients in whom rapid initiation of treatment is desirable (e.g., patients with severe symptomatic OSA, sleepiness while driving) and they declined PAP without PAP failure. PAP therapy can be initiated quickly while MAD initiation requires incremental titration of the device over weeks to months to attain optimal efficacy. * Severe or prolonged Oxygen desaturation: patients with severe oxyhemoglobin desaturation during sleep (e.g., nadir peripheral oxygen saturation \[SpO2\] \<70 percent), caution is warranted as oral appliance therapy may not provide optimal improvement in oxygenation. * Alcohol or illicit substance use at least daily * Unstable psychiatric condition * Current use of a GLP-1 receptor agonist (e.g., Zepbound, Wegovy, Ozempic, Mounjaro) with ongoing, active weight loss at the time of enrollment, or recent dose escalation within the prior 8 weeks.