Sinus pressure and dull pain under nostril in bone. no drainage/congestion. worried may be dental infection, but no pain in gums. how do i tell?

Expert: Self diagnosis is at best ineffective, at worst dangerous. You need to see an expert, a Dentist, who has more than 10,000 hours remaining and years of experience, to make that determination. Please call now.

See DDS for X-rays: Your dentist will do a thorough diagnosis, including any necessary X-rays, to see if the source of your pressure is in the teeth or your sinus.