Is there any direct correlation with air puffing through the corner of the lips and sleep apnea/sleep disorders?

I'm still working on getting the prescription for an APAP. It's kind of like getting Congress to approve a law and jump through hoops. When I can get the challenged people at the sleep clinic to finally get me a prescription for APAP, I'll post the results from Sleepyhead. In the meantime, I have noticed that on certain nights when I'm just flat out exhausted, sometimes I wake myself up a few times due to hearing the sound of me blowing air out of the corner of my lips. Not just a little bit, but pretty heavily, like full breaths. This only happens when I'm laying on my back.

My common sense makes me curious if this happens because the airway in the nasal/ area upper throat shuts off for a very short time period and basically forces the air out of the mouth instead because that's the only other place for it to go to escape on the exhale. Pretty sure that this probably happens more often than just a few times throughout the night and I'm wondering if anyone knows any direct correlation between sleep apnea or sleep disorders in general and heavy mouth puffing.

I know that some people on APAP/CPAP have this happen and they tape their mouths and such. What about people who do it naturally? Is it just something that happens or even more of an indicate of sleep apnea?

Mouth breathing is quite common, and considered by some to have detrimental effects on your sleep. See this video which is directed at the general population.

How to mouth tape for a better sleep