Root canal concerns. is it possible to have permanent facial nerve damage/paralysis from root canal?

The nerves to these different sites are physically separated, like separate branches of a tree. Work on/near the outer part of one branch does not affect the different branch (to your facial muscles).

The facial nerve does not innervate the teeth or gums, and a root canal procedure would not cause nerve VII damage or paralysis. If you have acquired Bell's Palsy, this is a coincidental event. There is NO cause and effect from dental interventions.