Chuck, I believe the issue with the jaw moving forward (and staying forward if you don't do the corrections) is that it screws up your bite. As I said, my first provider either did not care or did not know that the advancement could be corrected. In my case, getting the sleep apnea under control was the primary motive for getting a dental device and the heck with the jaw. The jaw advancement can be seen in the mirror in my case, it is a little like Marlon Brando in The Godfather but not as extreme. The advancement is not much, a few millimeters at time. And it has to be done gradually not all at once. Once the device is removed from the mouth most of the Marlon Brando appearance is gone, i.e. the jaw does not stick out much. I can feel the stiffness in the morning and if I do my excercises that goes away pretty quickly.
It would be interesting to find out how often and how many hours per night CPAP is commonly used. I use my dental device all night, every night. I don't think every CPAP user can say that. It would be interesting to hear some comments on that issue, I have not read the other forums so there may well be that discussion going.
Carl G, I have been using a dental appliance for probably 10 years now. My first provider was a maxillofacial surgeon who knew the device well and knew that the lower jaw would move forward but thought that was the price to pay. And my jaw did move. Now my second provider who specializes in only sleep apnea dental devices is very concerned about lower jaw movement. I have a mold called a morning positioner that I can use to move the jaw back in to position. I hardly use it because I find it easier to just rest my lower jaw on my hand while working on the computer in the morning. However, that is easy to forget. There are all kinds of exercises that you can do to correct this. Your dentist should be able to advise you.
In all this time I have never had a second sleep study to titrate my appliances. I tried to do one a couple of years ago but the setup was so uncomfortable that I could not sleep enough to get it done. Now at the five year point on my second device (Medicare only pays for one every 5 years) I will need to get a sleep study. I am hoping they will accept a home study because I cannot stand those labs, especially the last one.