To Original Poster,
It's a good question. I can understand your question and underlying concern. (I will admit that I am hoping that someone else will be able to post some studies to better answer your specific question, because I am too tired to go over to pubmed.gov and search around tonight).
I do not want to minimize the difficulties that people experience, but do want make some comments:
a) It can be difficult to determine the cause of ‘side-effects’, because there are so many conditions are associated with sleep apnea. For examples:
GERD & Acid reflux: people with this often have the problem with air-in-stomach, gas, bloating.
Sinus issues – well many people experience sinus issues without PAP.
Cold/Flu – People will post to say that they got a cold/flu from PAP. But, was it the PAP, or perhaps they were exposed to a virus in the grocery store or doc’s office.
b) PAP treatments have improved over the past few years. Everyone uses the acronym CPAP, but there is auto-PAP, bi-PAP, ASV-PAP which work better for patients depending upon the specific case. There has also been the introduction of features/accesories (exhalation relief, built-in humidifiers, ramp, data-capability, hose covers, heated hoses) that help with various issues. You would be amazed at the number of people (and medical professionals!) who are unaware that these are available.
Some comments regarding your specific situation, PAP versus dental appliance:
Based on 'a' above, consider if you have any associated conditions or issues that might play a role in either option.
You could ask your doc about prescribing a trial (weeks, months) of PAP to see how you do with it. Insurance often ‘rents’ PAP by the month on behalf of the patient. I have seen hunerous reports of this being done for patients..
IMO, a key advantage of PAP over dental applicane is data-capability. This allows for monitoriing of the effectiveness (AHI data) of the treatment. The data can be viewed daily, and a good sleep doc can review downloaded reports. Sleep apnea is beleived to gradually worsen with age, weight gain, so it's good to have that monitoring over the years. Also, even a mild condition is associated with higher risks of associated conditions, so some people want to monitor that they are fully treated (~ AHI < 5) verus "I feel better".
Good luck to you.