The op asked if a chin strap can solve the problem of opening your mouth while sleeping... in my experience it does and my leak rate has been zero ever since wearing one. Without the chin strap i'd wake up with air gushing out of my mouth... not anymore.palerider wrote: actually, Julie is right. clench your jaw tight, blow out through your lips.
your teeth aren't airtight, and that's all that a chinstrap keeps closed.
AVi123... mine is the CareFusion PureSom ruby adjustable #TMS-09ADJ (the one on the right in that video.) I think the lighting/camera made it appear red... it's actually burgandy. I believe the only difference is yours is XL.