What does this mean?
The roots of your upper back teeth sit very close to the floor of the sinus in your upper jaw, the maxillary sinus. In some people the roots reach up into the sinus, and the bone in between is as thin as paper. When one of these teeth is taken out, or when infection at the root tip wears that bone away, a passage can open between the mouth and the sinus. Because the sinus itself drains into the nasal cavity, liquid you take into your mouth follows this route and reaches your nose.
What sets this symptom apart from the things it resembles is that it stays on one side and happens only with liquids. If there is an opening, the liquid usually comes from one nostril only, solid food does not do the same, and there is no cough or choking feeling as you swallow. You may find it hard to puff out your cheek, your voice may sound as though it is coming through your nose, and you may notice air escaping from the socket. Leakage caused by a swallowing problem, by contrast, affects both sides, does not tell solids from liquids, and usually comes with coughing.
The timing tells you something as well. The problem most often starts in the first few days after an upper back tooth has been taken out. Small openings are expected to close on their own as long as the blood clot stays in place; above a certain width this is not expected, and the opening may become lined with tissue from its edges over time and turn into a permanent channel. The longer the passage stays open, the more likely it is that bacteria from the mouth are carried into the sinus and that a one-sided sinus infection settles in.
For liquid to pass into the nose there has to be an open route between the mouth and the sinus, and how that route forms differs from person to person. The headings below are not in order of frequency; they show the sources that need to be told apart at an examination.
Likely causes
What helps at home?
- Do not blow your nose, do not close one nostril and force air through the other, and avoid anything that builds up pressure such as blowing up balloons; pressure inside the sinus can reopen an opening that is in the middle of closing.
- Keep your mouth open when you sneeze, do not drink through a straw and do not smoke; sucking and sudden changes in pressure dislodge the blood clot.
- Do not probe the socket with your tongue, your finger or any object; you cannot work out how big the opening is this way, you only carry infection into it.
- Do not start leftover antibiotics or a nasal spray on your own; while the opening is still there, medicine may ease the symptom for a while but does not remove its cause.
- If it started after an upper back tooth was taken out and is not settling within a few days
- If foul-smelling or infected discharge is coming from the nostril on the same side
- If you have swelling in your cheek, increasing pain, a fever or a feeling of fullness under the eye
- If the extraction site keeps bleeding or a bad taste in your mouth will not go away
- If liquid passes into your nose although you have never had a tooth taken out, and it comes with coughing, a choking feeling or a change in your voice
Frequently asked questions
- It started after an extraction: will it close on its own?
- It depends on how wide the opening is. Small openings are expected to close within a few weeks, as long as the blood clot is protected and you avoid anything that builds up pressure. Above a certain width, closing on its own is not expected and the opening has to be closed surgically. You cannot tell from the outside which group you are in, so rather than waiting to see, the decision should be made with an examination and, if needed, an X-ray.
- I have never had a tooth taken out: can it still happen?
- It can. The thin bone between the mouth and the sinus can also become thinner and give way because of long-standing infection at a root tip, a cyst or a growth in the jawbone, or surgery carried out earlier. Liquid passing into the nose is also not always down to this; it is seen as well when the soft palate cannot close off the passage to the nose during swallowing. That picture is not a matter for dentistry but for an ear, nose and throat assessment and, where needed, a neurological one.
- Will sinus medication clear this up?
- While the opening is still there, medicine on its own is not expected to be enough. Antibiotics and a nasal spray may push back the inflammation in the sinus for a while, but as long as the route from the mouth into the sinus stays open, bacteria keep being carried through and the symptom can come back once the medicine runs out. In this situation, treating the sinus and closing the opening need to be planned together; your dentist and an ear, nose and throat specialist decide the order between them.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.