Q. Dr. Patel, I had a major sinus infection for about a week now. My dentist took an x-ray of #2 and #3 (both had root canals in the past with no complications)with no issues. Apparently, I have deep sinus cavities. Some info recently: #2 crown broke a month ago and was reordered for replacement next week. It’s been crownless. Now, #3 hurts bad. The dentist gave me pain relieve and antiobiotic. But #3 still #3 hurts. Is it sinus related? Is it becuase #2 crown is not there and things are shifting?