Reducing Obstructive Sleep Apnea After Hypoglossal Nerve Stimulation Through Mandibular Advancement

Inclusion Criteria:

* Age ≥ 18 years.
* Ability to read, write, speak, and understand English.
* Failure of hypoglossal nerve stimulation (HGNS) therapy, defined as intolerance to HGNS or insufficient AHI reduction based on modified Sher criteria while using HGNS.
* Ability to insert and remove the mandibular advancement device (MAD) independently.
* Ability to complete all study assessments and evaluations, including home sleep apnea tests (HSAT).
* Ability to abstain from any other treatment for obstructive sleep apnea (OSA) during the entire study duration.
* Access to an internet-connected device (phone, tablet, or laptop) with a camera.

Exclusion Criteria:

* Age over 70 years.
* Inability to use a mandibular advancement device (MAD), defined as having fewer than 9 healthy teeth per dental arch.
* Prior intolerance to MAD therapy.
* Previous participation in a trial involving the use of oral appliances.
* Chronic nasal obstruction.
* Dependence on or frequent use of medications that alter consciousness, respiration, or alertness.
* Insomnia and/or use of medications to treat insomnia.
* Sleep disorders such as narcolepsy, insomnia, restless leg syndrome, or other disorders affecting sleep, and/or use of medications to treat such disorders.
* Substance abuse.
* Unstable psychiatric disorders.
* 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.