Consistent CPAP use of at least four hours per night on most nights is often needed for symptom relief

https://www.scribd.com/document/997941580/How-a-Sleep-Apnea-Oral-Appliance-Is-Fitted-Step-by-Step-Overview-207415

Consistent CPAP use of at least four hours per night on most nights is often needed for symptom relief and to meet insurance compliance requirements.