Sinus Infection or Toothache? Both Were Involved

Quick answer: Sinusitis usually makes several upper teeth ache at once, worsens when you bend forward, and comes with a blocked nose. A tooth problem is one tooth, tender to tapping, and responds to hot or cold. Occasionally an upper tooth is the cause of the sinusitis, and then you need both treated.

The call

Dov, 44, from Ramat Shilo, had been treated for sinusitis twice over four months — decongestants, then an antibiotic. Each course helped a little and nothing resolved. He had a dull ache across his upper left teeth, a blocked left nostril, and a bad smell he could detect himself and was embarrassed about.

His doctor had suggested, sensibly, that he see a dentist before a third course.

What we found

Most of his upper left teeth were mildly tender to percussion, which is exactly what sinusitis does. But one — the upper left first molar — was markedly more tender than the rest, gave no response to cold, and had a large old filling with recurrent decay.

The x-ray showed a lesion at the palatal root apex that had eroded the thin floor of the maxillary sinus. A CBCT scan confirmed it: the root tip was communicating directly with the sinus, and the sinus lining above it was thickened in a dome shape centred exactly on that root.

This is odontogenic sinusitis — sinus infection caused by a tooth. It accounts for a meaningful share of one-sided maxillary sinusitis, and it is routinely missed because patients go to the doctor rather than the dentist for sinus symptoms. The tell-tale features are that it is unilateral, that it does not respond fully to standard sinusitis treatment, and that the discharge smells foul, which is characteristic of the anaerobic bacteria that come from teeth.

The distinguishing features, in general:

Points to the sinus: several upper teeth ache together, worse bending forward or lying down, blocked nose, recent cold, pain on both sides, teeth respond normally to cold. Points to a tooth: one tooth clearly worse, tender when tapped, no response or a lingering response to cold, no nasal symptoms, and often a history of a large filling or previous treatment on that tooth.

What we did

Root canal treatment on the molar, taking particular care with irrigation because of the direct communication with the sinus — pushing irrigant beyond the root tip into a sinus is a genuine risk and it is avoided by careful length control and gentle, side-vented needles.

We wrote to his ENT specialist and to his family doctor explaining the dental origin, and he was reviewed by ENT six weeks later rather than being started on a third antibiotic.

The outcome

The nasal blockage and the smell resolved within three weeks of the root canal — before any further sinus treatment. At the ENT review the sinus was clear and no surgery was needed. The tooth was crowned two months later.

Four months of sinusitis treatment had been aimed at the wrong organ.

What to do if this happens to you

1. Tap your upper teeth with a fingernail. One clearly sore tooth points away from the sinus.
2. Note whether it is one side only. Sinusitis from a cold is usually both sides; from a tooth, one.
3. Mention any foul smell or taste. It is a strong clue to a dental origin.
4. See a dentist if two courses of sinus treatment have not worked.
5. Ask for a CBCT scan if standard x-rays are equivocal. It shows the sinus floor properly.
6. Ask your dentist to write to your doctor or ENT. Joined-up care shortens this considerably.

Sinus treatment not working? Ramat Beit Shemesh Urgent Dental Care can rule the teeth in or out. 055-985-8845 · WhatsApp https://wa.me/972559858845 · Harav Kook 28/1, Beit Shemesh.

Based on real cases treated at the clinic. Names have been changed.