Polysomnographic (PSG) recordings
Nasal airflow
This study consisted of two PSG recordings for each participant: one at baseline without MAD and one at 3-month follow-up with MAD in situ. A digital PSG system (Embla A10, Broomfield, CO, USA) was used and recorded electroencephalogram (EEG) (FP2-C4/C4-O2), electrooculogram (EOG), electrocardiogram (ECG), and submental and anterior tibial electromyogram (EMG). Nasal airflow was measured by a nasal pressure cannula, and blood oxygen saturation was measured by finger pulse oximetry. Straps containing piezoelectric transducers recorded thoracoabdominal motion, and a position sensor (Sleepsense, St Charles, IL, USA) attached to the midline of the abdominal wall was used to differentiate between supine, prone, right lateral, left lateral, and upright positions [PSG parameters, including sleep and respiratory variables, were analyzed following the recommendations of the American Academy of Sleep Medicine [