I have been struggling with this for a couple years. I was confirmed with sleep apnea, and I am 100% positive it relates to the tongue/pallet connection. Doctors/tests have been of zero help.
I am a NOSE breather.
I had a sleep apnea mouth guard made by a spealist, but it didn't prohibit my tongue from traveling to the roof of my mouth.
here are some things that have helped me to be about 60% better, but it is a constant struggle.
First, I sleep with a plastic thing that's meant for teeth grinding. I string dental floss back and forth across it so that my tongue can't seal with the roof of my mouth.
I also found that allergy medicine helps at night. When I take it, its one with 5 mg Phenylephrine HCl, and a couple other ingredients.
I also cut back on diary products. They increase mucus.
My personal theory is that the problem stems from bacteria. The trapped air increases CO2 which ups bad bacteria. This bad air gets into sinus without any symptoms. Quite by chance I found that the Phenylephrine helps - I had a cold and started taking it. I'm nervous about taking it too much, but it does help.
I'd be very interested in what others have done.
I am having a similar problem and wanted to add that when my tongue is on the roof of my mouth, breathing through my nose is most definately affected. Try it. It appears that the position of the tongue crucial to normal breathing although I find that I can breathe but not without more effort and it's frighting when you are resting b/c it seems possible that during deep sleep I might not be able to make the adjustment and fail to breathe. I am considering the sleep study and will try not sleeping on my back to see if that helps for now.
I hope you have gotten answers for your Jan 2009 post. If not, here is something to think about. Normal breathing is nasal breathing, and when you have nasal breathing, it is ok for your tongue to fit up against the roof of your mouth and against your palate. In fact, this actually helps the air you breathe in go directly down into your lungs.
If you find that your tongue is blocking your breathing, it appears that you are trying to breathe through your mouth. In this case, having your tongue rest in its natural position is a problem. However, it's not really your tongue that's the problem. The real problem is whatever is keeping you from breathing through your nose.
Were you having a really bad cold? Have you started having allergies or have they become significantly worse? Did you have an injury to your nose? If you can't breathe through your nose, you need to see an ENT. Healthy breathing (for many reasons) starts with getting air through your nose. Good luck!!
Couple issues to address... if your tongue is blocking your airway during sleep, you need to be on treatment to keep your airway open until for whatever reason it is no longer an issue. Has your doctor ordered a sleep study to see how bad it is? Have you seen an ENT to see if your tongue is enlarged and to determine why? I don't know all the possible causes, but I did read that hypothyroid can cause the tongue to be larger, but an ENT should know all the possible causes. Any doctor can order a thyroid panel to assess that.
Till you get answers, you might try sleeping on your stomach, or elevating the head of your bed a few inches and staying off your back. If you have a family doctor, they can start the ball rolling by ordering the blood tests and can even order a sleep study. Hope you find answers soon.