Yawning's effect on SaO2 Oxygen level

I have a class 2 malocclusion (over-bight, crowded teeth) and TMJ symptoms.
I use a Contec Pulse Oximeter to measure SaO2 levels during CPAP usage.

I just found that when I open my mouth real wide (as in yawning),...my SaO2 level temporarily increases about 5 percentage points from 90 to 95%.
This is "not bad",

I think this may relate to what they call "central apnea". It seems to me that pharyngeal CO2 sensing nerve bundles pass near the mandibular joint(thingy, whatever). And at this point, I'm not sure if I am witnessing something that needs to be fixed(because of the TMJ), ....or just the natural "yawn reflex".

I'd like to hear from other Pulse Ox users with low O2 levels, ....whether they have (or now) observe(d) the same thing. Thanks.

ZZZZZzzzzzzzz..........