Somnodent vs Herbst in Mild and Moderate OSA Patients

Inclusion Criteria: * 18 years and older * Ability to speak, read, and write Dutch. * Ability to follow-up. * Ability to use a computer with internet connection for online questionnaires. * Diagnosis with symptomatic mild or moderate OSA (5 \< AHI \< 30). * Expected to maintain current lifestyle (sports, medicine, diet, etc.) Exclusion Criteria: * Untreated periodontal problems, dental pain, and a lack of retention possibilities for an MAD. * Medication used/related to sleeping disorders. * Evidence of respiratory/sleep disorders other than OSA (eg. central sleep apnea syndrome). * Systemic disorders (based on medical history and examination; e.g. rheumatoid arthritis) * Temporomandibular disorders (based on the function examination of the masticatory system). * Medical history of known causes of tiredness by day, or severe sleep disruption (insomnia, Periodic Limb Movement Disorder, Narcolepsy). * Known medical history of mental retardation, memory disorders, or psychiatric disorders. * Reversible morphological upper airway abnormalities (e.g. enlarged tonsils). - Inability to provide informed consent. * simultaneous use of other modalities to treat OSA. * Previous treatment with a MAD.