One side of my nose is blocked: could a tooth be behind it?

The nose is made of two separate halves, and normally these halves swell and open in turn. With a cold, an allergy or a change in the weather, the blockage usually involves both sides or moves from one to the other. A blockage that settles on one side and stays in the same place for weeks points to a structural or an established cause. In adults, that list starts with a deviated septum, enlarged turbinates and a one-sided polyp. In children, a foreign body pushed up the nose, at any age blood collecting inside the septum after an injury, and, rarely, growths inside the nose can produce the same picture.

There is one heading on that list that most Turkish sources never mention: sinusitis of dental origin, known in medicine as odontogenic sinusitis. The roots of the upper molars and premolars rest against the floor of the maxillary sinus; in some people the bone in between is as thin as paper. Inflammation settled at the tip of a root, advanced gum disease, root filling material that has passed into the sinus, an opening left between mouth and sinus after an extraction, or an implant that has gone into the sinus can all get past that layer and infect the sinus. Because the sinus is involved on one side, the nose is blocked on one side too.

Its share is not small. A comprehensive review of the field relates that between 25% and 40% of chronic maxillary sinusitis is of dental origin, and that in cases where a scan shows filling of the maxillary sinus on one side only, this figure rises to between 45% and 75%. In other words, not thinking of a dental source when faced with one-sided filling of a sinus means wiping out half the possibilities from the start.

What really makes the picture difficult is that a considerable proportion of patients have no toothache. Reviews of the field report that up to 29% of cases come in without any noticeable toothache; the state-of-the-art review we cite likewise writes that most of these patients have no toothache. A dead tooth does not hurt, and a tooth that does not hurt does not come to the patient's mind. So the sentence my tooth does not hurt, therefore it cannot be a tooth is not a reliable way of ruling it out.

Smell is the most valuable clue you have in making this distinction. With sinusitis of dental origin, one-sided discharge with pus and a bad smell the patient notices in their own nose are typical; in a study collating how often the symptoms occur, the proportion of patients reporting a bad smell or a bad taste is given as between 26% and 48%, blocked nose as around 45%, and discharge as two thirds. The average duration of the complaints is measured in months, with the review quoting a median of six months. If you have carried a one-sided, foul-smelling blockage for months, this picture may fit you.

The most practical piece of information here has to do with imaging. Having had a sinus scan whose report says nothing about a dental source does not clear your teeth: the same review reports that radiologists miss dental pathology in 60% to 70% of these cases, and that in about 30% of cases due to inflammation at the tip of a root, the finding is very faint on the scan or not visible at all. That is why the image also needs reading by an eye that knows teeth, and the investigation that best shows the relationship between the upper back teeth and the floor of the sinus is a cone beam CT scan (CBCT).

The logic of treatment follows from this. While the source is in a tooth, carrying on with a nasal spray and antibiotics alone gives temporary relief and the picture comes back. The review states that, while there is treatable dental pathology, an oral antibiotic on its own is ineffective and should be counted as an interim step that buys time, whereas in cases where both the tooth and the sinus are dealt with, the rate of improvement is very high. So the right question is not which clinician, but whether two clinicians are working together.

The two lists below do not make a diagnosis; they show which clinician it makes more sense to start with. The firm distinction becomes clear with an examination and imaging.

With sinusitis of dental origin there is no single door; what finishes the job is the two fields working together. The sequence below saves you both time and repeated treatment.

1. 1

   An ENT examination

   With a one-sided blockage, the first step is looking inside the nose with an endoscope. The septum, the turbinates, polyps, a foreign body and pus coming from the middle meatus are assessed here. Seeing pus on one side strengthens the case that the source is the maxillary sinus.

2. 2

   Assessing the upper back teeth on the same side

   Ask your own dentist to assess your upper premolars and molars one by one, with a vitality test, by tapping and with pocket measurements. Because a tooth that does not hurt can also be the source, the testing should not be limited to the tooth the patient points to.

3. 3

   The right imaging

   A panoramic X-ray shows the relationship between the root tips and the floor of the sinus poorly in the upper back region. A CBCT scan is preferred in this picture because it shows the lesion at the tip of the root, the integrity of the sinus floor, a foreign body inside the sinus and thickening of the lining all together.

4. 4

   Having the image read by an eye that knows teeth

   A sinus scan report that says nothing about dental pathology does not clear your teeth; the review reports that this finding is missed in most cases. Show the image to your dentist as well and ask for the root tips of the upper back teeth to be looked at separately.

5. 5

   Treating the source

   Once the source tooth is found, the route is root canal treatment, redoing a root canal treatment, root-end surgery or extraction. If there is a root fragment or filling material that has gone into the sinus, it has to be removed. If the sinus itself has stayed blocked, an ENT specialist comes in during the same period.

6. 6

   Confirming the result

   Seeing the blockage and the smell clear shows that the treatment has worked. If the complaint carries on, either the source was not fully removed or there is a second cause; in that case the assessment starts again.

There is no single treatment for a one-sided blockage. The routes below separate out according to the source.

The points below are the losses most often suffered with this picture. We are writing them so that you can ask the right questions whichever clinician you see.

The time depends on the source. The intervals below are the courses seen most often; the plan of the clinician following you takes priority.

1. The first four weeks with simple sinusitis

   The NHS states that sinusitis mostly clears on its own within four weeks, and that if there is no improvement after three weeks of self-care, you should see a doctor. A one-sided picture going beyond this time calls for another cause to be looked for.

2. After the source tooth has been treated

   Once the source is gone, a clear improvement in the smell and the discharge usually starts in the first few weeks. A sinus lining that has been thickened for a long time can take longer to settle completely.

3. When the tooth and the sinus are dealt with together

   The review reports that when both the dental and the sinus pathology are treated together, the rate of improvement is very high. In cases where only one side of it is treated, the picture tends to come back.

We do not give a single figure here, because if the source is the septum the job ends with the ENT specialist, while if it is a tooth the scope can extend from root canal treatment to extraction and an implant. These are the items that determine it:

Whether the source is a tooth or the nose

Septum and turbinate surgery and dental treatment are separate specialties and separate scopes. A figure given before the source has been identified changes at the clinic.

How much imaging is needed

A panoramic X-ray gives the first idea; a CBCT scan may be needed for the sinus floor and the root tips.

Whether the source tooth can be saved

Redoing a root canal treatment, root-end surgery and extraction are separate scopes. That decision is given by the CBCT scan.

How many teeth are affected

If the tooth infecting the sinus stands alone, the plan is narrow. If there are other losses in the same mouth, the plan is built around the whole, not around a single tooth.