Chronic Maxillary Sinusitis

[Sabio]

In June of this year I had a root canal done on an upper rear tooth.   The tooth started hurting around midnight and by morning when I could find a dentist the pain was almost unbearable.   The pain was relieved after the root canal however a few days later I started experiencing pressure in the maxillary sinus cavity directly above the said tooth.  I went to an EarNoseThroat doctor who took an X-ray which confirmed mucous in the maxillary sinus.  He prescribed FACTIVE gemifloxacin-mesylate 320mg tablets which I took one per day for 5 days.   I didn´t notice any impovement.  

I suspected the tooth with the root canal was still the cause of the problem because it also fractured vertically into the gum.   Finally I had this tooth extracted hoping it would solve the sinus problem.   Unfortunately the sinus infection continued after the extraction and to make matters worse the tooth next to the extracted tooth is now giving me pain.   X-rays of this tooth (last tooth before the wisdom) now show possible degradation in one of its roots.    
My questions are:  
Should I try another antibiotic to battle the sinusitis (eg Amoxycillin/Clavulanate 875/125mg) ?  
Could the sinus infection be causing a problem in the root of a perfectly good tooth?  
Will a CT scan help?  
Any other info you can suggest would be appreciated.  

PS.. I am in Brazil and having some trouble trusting the medical system here.  

[researchwriter]

I had a failed root canal that I left untreated for 7 years.
During that period of time I had recurring pink eye and sinus infections at least 4 times a year.
Both were treated with antibiotics, but always returned with a vengence.
I finally had oral surgery on the root because a bubble protruded on my gum in the root area.
This surgery proved unsuccessful.
I finally surrendered and had the tooth extracted, and have been sinus infection free and pink eye free for 5 years!

[Sabio]

Thanks for the info.   Do you recognize the antibiotic prescribed for me (FACTIVE gemifloxacin-mesylate 320mg)?    Which antibiotic do you recommend?  From some reading about Sinusitis it appears that 5 days is not enough time to cure the disease with antibiotics.

I am also inhaling a saline solution to relieve the mucus buildup.

[Vivek V Gurudutt, MD]

The relationship between maxillary teeth and the maxillary sinus can sometimes be a difficult one to ascertain.  There are times when an infected tooth from the maxilla can lead to infections of the maxillary sinus.  It is also possible to have sinus problems which can lead to referred pain to the jaw.  However, it is not very likely to have a sinus infection lead to tooth degradation.  That needs to be worked up further to find out a cause.  If you are actively infected, antibiotics are helpful.  A ct scan may give more information that your oral surgeon may be able to use.  Definitely follow up with your doctor.  An oral surgeon and an ent may have to work together to take care of each issue.  Good luck.