Every winter we see a handful of patients who have already been to a GP, already been told their throat looks fine, and are still swallowing carefully on one side. The throat is not the problem. The lower wisdom tooth on that side is, and the pain has simply travelled.
This happens often enough that it is worth explaining the anatomy, because once you understand why the pain moves, the difference between a throat infection and a wisdom tooth becomes fairly easy to work out at home.
The mechanism
A lower wisdom tooth that is only partly through the gum has a flap of tissue sitting over the back of it, called an operculum. You cannot clean under a flap. Bacteria and food collect in the space, the tissue becomes inflamed, and if it tips over into infection the condition has a name: pericoronitis.
The reason that turns into a sore throat is where it sits. The area behind the last lower molar is a few millimetres from the tissue planes that run down beside the tonsil and behind the jaw. Swelling in one of those spaces does not stay put; it spreads along the plane of least resistance. So the inflammation starts around a tooth you can barely see and is felt as a raw, pulling pain when you swallow, on that side only.
Upper wisdom teeth do something different. They sit directly below the floor of the maxillary sinus. An infected or heavily decayed upper wisdom tooth can inflame the sinus lining above it, and sinus drainage down the back of the throat produces its own sort of soreness. Less common, but I see it.
Telling the two apart
A rough guide, and it holds up more often than not:
| Points to a wisdom tooth | Points to a throat infection |
|---|---|
| Sore on one side only, and the same side every time | Sore across the whole throat, or both sides |
| Worse when you swallow on that side, fine on the other | Worse generally, both sides equally |
| Your jaw feels stiff, or you cannot open as wide | Jaw opens normally |
| Bad taste or smell from the back of the mouth | No unusual taste |
| No cough, no runny nose, no blocked ears | Often comes with cold symptoms |
| The gum right at the back is tender if you press it | The gum at the back feels normal |
| It has happened before, in the same spot | New, or follows a pattern of colds |
The jaw stiffness is the most reliable single clue. In dentistry it is called trismus, and it happens because the muscles that close your jaw sit immediately next to the inflamed area and go into a protective spasm. Tonsillitis does not do that. If you cannot get two fingers between your front teeth, and your throat hurts on one side, the odds are strongly on a wisdom tooth.
The other reliable clue is history. Pericoronitis recurs. If this is the third time in eighteen months that the same corner of your mouth has flared during exam period or after a heavy week, that is a pattern, and patterns do not come from viruses.
The bit that is not optional
Most pericoronitis is uncomfortable and manageable. A small proportion is not, and the difference matters.
Ring us the same day, or present to a hospital emergency department, if you have any of these:
- Swelling under the jaw or in the neck that is visibly growing.
- Difficulty swallowing your own saliva.
- Any change to your breathing or your voice.
- Fever with the swelling.
- Inability to open your mouth more than a centimetre or so.
Infection in the floor of the mouth and neck can compromise an airway. It is uncommon, it is treatable, and it is not something to wait out over a weekend. We keep same-day emergency slots at the Blackburn practice for exactly this, and we would far rather look at something that turns out to be minor.
What actually gets done about it
When you come in with this, there are two separate problems: the flare, and the tooth that keeps producing it.
Settling the flare. We examine the area and take an OPG, the panoramic X-ray that shows the whole tooth including the part under the bone, its angle, and its relationship to the nerve canal below. Then the area under the operculum gets irrigated properly, which alone brings a lot of relief because it removes what is feeding the infection. Antibiotics are used where there is genuine spreading infection, not as a default. Warm salt-water rinses at home help mechanically; they are not a treatment on their own.
There is one detail here that people find surprising. Quite often the lower flap is being traumatised by the upper wisdom tooth biting onto it every time the mouth closes. Where that is what is happening, removing the upper tooth, which is usually a straightforward extraction, can settle a lower flap that has been flaring for a year. It is worth checking before assuming the lower one has to go.
The tooth itself. Once the acute episode has settled, the question is whether the wisdom tooth has a future. If it is well positioned and simply needs the area kept clean, we keep it. Airflow is genuinely useful here: Guided Biofilm Therapy uses a warm spray of water, air and erythritol powder that gets under a gum flap where a brush and a hand scaler cannot reach, and for some people a regular clean of that corner is the whole solution.
If the tooth is impacted and the flap will never be cleanable, then it is coming out at some point, and it is far better to do that at a time of your choosing than during the next flare. Dr Kerry Chen does all the complex extractions here, in our own chairs on Canterbury Road, so an impacted lower wisdom tooth is assessed and removed in the same practice rather than referred elsewhere. Happy gas is available in the chair, and oral premedication if you would rather arrive already settled. We do not offer general anaesthetic or hospital sedation; if a case genuinely needs a theatre, we say so.
Why not just take antibiotics again
Because antibiotics treat the infection, not the flap. The flap is a mechanical problem: a roof over a space you cannot clean. Every course buys a few months, and every flare leaves the tissue a little more scarred and the next episode a little more stubborn. I would rather see someone once, work out whether the tooth is keepable, and either make it cleanable or take it out, than sign a third script and hope.
That is broadly how we approach everything here. Find what is actually causing it, then fix it in a way that does not need redoing in a year.
Booking
If you have a one-sided sore throat with a stiff jaw and a bad taste at the back, that is a dental appointment, not a wait-and-see. Call (03) 8838 8820 or text 0435 025 318. We are at 129A Canterbury Road, Blackburn, with parking on site, and we open at 8am on Wednesdays and Fridays if you need to get in before work.
Related reading: what erupting wisdom teeth actually feel like, the signs that make a wisdom tooth an emergency, and how we handle wisdom teeth removal in Blackburn when a tooth does need to go.