Mouth opens now and didn't before surgery

I have a strange issue going on.  Just wondering if anyone else has experienced this.  I have used bipap for 6-7 years and adjusted to it extremely well from the very beginning.  However, since my surgery, my mouth opens, causing me to wake frequently.  I have never had this problem before.  In fact, I have had to start wearing a chinstrap.  I don't mind the bipap mask, but the chinstrap sucks.  Any ideas?

I am a mouth breather so I have a full mask, but I have heard people say they have used the white surgical tape and taped their mouth closed. I dont know that I would, but they say it works.

I was a mouth breather before bipap, too.  But from the moment I tried bipap (and I mean even during my sleep test) I breathed through my nose and never had a problem until now.  I think I am going to order a full mask the next time I'm eligible to get another mask.  I have to wait about another month before I get a new mask.  Thanks for the input.

I'm having the same exact problem, and awake with my mouth and lips super dry!   It never happened before surgery and I adjusted very fast to my mask over 8 years ago. I'm going back to sleep lab at the end of the month for another evaluation to see if maybe there is too much air being forced through the mask. I'm sure it needs adjusted my now with my loss.  I don't want to go the chinstrap route...lol  

I developed the same problem and my Dr. ordered the new mask, no chin strap on my C-PAP mask.  My problem is the full mask is causing the skin on my nose to break down and be sore all the time (or worse)  We have to look into a different solution, maybe a new mask.

I WAS BROWSING THE FORUMS AND LOOKING FOR SOMEONE THAT HAD A PROBLEM WITH THE CPAP MASK MAKING THE SKIN ON THE NOSE SORE AND RED AND EVEN BREAKDOWN AT TIMES. I NOTICED AFTER I LOST ABOUT 50 LBS THAT THE MASK SEEMS TO LEAK SO I TIGHTEN IT AND NOW I AM HAVING SKIN PROBLEMS ESPECIALLY ON THE NOSE. WHAT DID THEY DO FOR YOU.

I thought that it never happened to me before surgery either. My husband told me that it did. I only noticed it after surgery though. My cpap tech told me that it could be that before I taking in more liquids and may not have gotten as dry as I do now. I do know that I am not getting as much water as I am supposed to. I did get more before surgery but this still seems like a weird answer.

My mouth isn't opening but I do wake up very very dry ... it's do to taking in less fluid.

I just keep water by the bed to take a drink. 

This happened to me too, I have success using "Paper Tape" from the first aid section of the pharmacy. A fellow CPAP user told me about this type tape. Good luck!