Jim Macklin wrote:
OK, you're right, no possible way tissue can heal over and
create a pocket, trapping air/gas in the jaw.

I know you're trying to be facetious but that is correct...by the time
that wound is healed any gas is gone, not that there really would have
been much gas in there anyway because that hole gets filled in by
clotted blood and fibrin and starts to organize before the gum is healed
shut. Any gas got absorbed. The body just doesn't allow an empty
air-filled space to persist with rare exception.




The bends is gas in solution coming out of the tissue/blood
faster than it can be exhaled.

Certainly not the situation in this scenario.



Of course, bacteria in a
closed pocket might be producing gas at a rate that is
absorbed and exhaled , but that evolved gas would expand
with altitude. But you're right, no possible reason to make
a comparison.

Most infections are not gas producing. The ones that are cause life
threatening illness. You'll be too sick to even think about flying.
Probably if you even have a non-gas-producing infection in a closed
pocket (called an abscess) you will not feel like flying. You would
likely be in pain.