Why B3?
What type of B3....straight niacin? or niacinamide?

If it is niacin, you could be having nerve symptoms ... it causes flushing and tingling. I would stop the B3 for a while and see what happens.

I'd get testing for B12. And see if you are low. Some paresthesias on the face are low calcium related to low Vit D status. So getting D tested is a good idea too.

The nerve distribution you describe sounds like trigeminal involvement. Did you get inhaled flu vaccine? Have you had chicken pox in the past? Herpes Zoster can activate and give pain symptoms without the rash. You can ask for blood work to measure Herpes titres to see if they are elevated.
Inhaled flu vaccine has been implicated in Bell's palsy which involves the trigeminal nerve. But your description is only sensory, which suggests shingles without rash.

I can't comment on the dental aspect of this, but I am sure Bryanna will be here when she gets a chance.