Upper teeth problems can cause problems. By all means, get your teeth fixed even if they are not the source of your problems.
As for your nose. I would consider doing a few things. Such as: nasal irrigation.
See here: http://www.njc.org/disease-info/treatments/alt-ther/nasal-wash.aspx
I use a Gerber brand nasal bulb. You might try Afrin, also. However, do not use that for more than 3 days.
Continue with occasional nasal irrigation. You might also try NasoFresh (non habit forming.)
I occasional do a nasal irrigation and use NasoFresh. You may need a RX but I would try these first.
Good luck.
The most likely cause of this is a sinus infection. This could also be directly related to a tooth problem. A CT of the sinuses will help to clarify the situation and lead to a more lasting therapy.