Participants
OSA symptoms, OSA, apnea, daytime sleepiness, snoring
Eligible patients, diagnosed with OSA at four sleep centers in the Netherlands (Onze Lieve Vrouwe Gasthuis Ziekenhuis (OLVG), Nederlands Slaap Instituut, Medisch Centrum Jan van Goyen, and AMC), were referred to the department of Oral and Maxillofacial Surgery of AMC to participate in the present study. The inclusion criteria were: 1. ≥ 18 years old; 2. ability to speak, read, and write Dutch; 3. ability to follow-up; 4. ability to use a computer with internet connection for online questionnaires; 5. diagnosis with symptomatic mild or moderate OSA (5 ≤ apnea–hypopnea index (AHI) ˂ 30 events/hour) with at least two OSA symptoms (e.g., snoring, fragmented sleep, witnessed apneas, and/or excessive daytime sleepiness determined by Epworth Sleepiness Scale (ESS) [