CPAP vs Oral appliance

CPAP (Continuous Positive Airway Pressure) and oral appliances are two different types of treatment for sleep apnea, a condition in which a person's airway becomes blocked during sleep. CPAP involves the use of a machine that delivers air pressure through a mask to keep the airway open. Oral appliances, on the other hand, are small devices that are worn in the mouth to help keep the airway open.

Recommended by the American Academy of Sleep Medicine, oral devices – also called oral appliances – can be used for the treatment of mild-to-moderate obstructive sleep apnea (OSA). The question of which treatment may be better for someone with sleep apnea depends on a number of factors, one of the greatest being their compliance with the treatment. If a patient is currently using CPAP successfully, then there may be no need to search for an alternative.
However, if a patient is not using their prescribed CPAP, dentists who have a specialty in dental sleep are in the prime position to recommend another therapy. Ultimately, the best device is going to be the one that patients will actually use as there are many dangers to leaving sleep apnea untreated.

Sources:

The National Sleep Foundation:  https://www.thensf.org/ 
Sleep Foundation:  https://www.sleepfoundation.org/ 
American Academy of Sleep Medicine: https://aasm.org/