I haven't seen Medicare cover dental devices for sleep apnea (but I could be wrong). I've seen regular insurance cover it on occasion, but it really depends on your policy. You can see an ENT, but not all ENTs are able to determine which option would be good for you. In light of the fact that you have a history of hypertension and stroke, you should consider getting it treated one way or the other. CPAP is covered by Medicare and is the best initial way of treating it. Once you're started on it, you can take your time looking at other options.