From all patients, two full polysomnographic (PSG) recordings were obtained in the sleep laboratory of the Slotervaart Medical Center, using Siesta hardware and Pro-Fusion software (Compumedics, Abbotsford, Australia): one before therapy assignment (baseline PSG) and one after 6 ± 2 months (mean ± SD) of treatment (therapy evaluation PSG). For the MAD and nCPAP groups, the third and fourth PSG recordings for therapy evaluation were performed 6 months and one year after the first therapy evaluation (long-term follow-up). The primary and secondary outcome measures were obtained at baseline and at therapy evaluations.