Jaw pain on one side, and when it is not your wisdom teeth

Most one-sided jaw pain is a problem that can be worked out at an ordinary appointment. A small number of presentations cannot, and two of them are not dental at all.

A dental infection that has reached the tissue spaces around the airway is a hospital problem from the moment it does so. It is assessed in person, not over the telephone, and it is managed in hospital rather than in a dental office.

Altered sensation after recent surgery: report it immediately

New numbness, tingling or a burning feeling in the lip, chin, tongue or cheek after recent dental surgery goes back to the surgeon who operated on the day you notice it. Do not wait for a scheduled post-operative review, and do not wait to see whether it has faded by the morning. What follows altered sensation — the examination, the mapping of the affected area, and any referral — is time-critical, and the date it started is part of the record.

Same day, by telephone

• New numbness or tingling of the lip, chin, tongue or cheek where there has been no recent surgery. It is uncommon, it has several possible causes, and none of them are worked out at home.
• Swelling that has moved out of the gum and into the cheek, under the jaw, or towards the eye, with or without a temperature.
• An inability to open the mouth more than about a finger-width and a half when swelling is present.
• A temperature at or above 100.4°F (38°C) alongside facial swelling or a sore area at the back of the jaw.
• Aching or tiredness in the jaw that comes on while chewing and forces you to stop, in anyone over about 50, particularly alongside a new one-sided headache or tenderness of the scalp. That combination needs medical assessment the same day, and it is not a dental problem. If vision blurs, dims or is lost in either eye, it is an emergency department rather than a same-day call.
• Pain that has not responded to over-the-counter analgesia taken at the dose printed on the label.

Everything below assumes none of the above applies. If one of them does, stop reading and make the call.

Before any of the causes can be separated, the pain has to be located, and patients are usually more precise about this than they expect to be. Close your mouth, and try to cover the sore spot with one fingertip. Whether you can is itself diagnostic information.

Pain that sits under one fingertip is usually coming from a structure that small: a single tooth, or the gum flap behind the last one. Pain you have to describe with a flat hand across the cheek and temple is usually muscular. Pain that sits in a small hollow immediately in front of the ear canal, which you can feel move when you open and close, is the joint.

There are six places one-sided jaw pain is commonly felt, and each points in a different direction. The gum behind the last lower tooth. A single tooth, upper or lower. The dip immediately in front of the ear. The flat pad of muscle over the angle of the jaw, and the fan of muscle at the temple. Below the cheekbone, under the eye. And the ear itself, or just under the jaw at the top of the neck.

Write the answers down before the appointment. A short record of three or four episodes hands the clinician the pattern directly, instead of something reconstructed from memory in the chair under a bright light.

These are patterns rather than rules, and the reason a case looks confusing is very often that two of them are present at the same time — a partly erupted wisdom tooth and a clenching habit, for instance, or a sinus infection in someone who also has decay.

Two rows can be true at once. Where they are, treating one and finding the pain only partly improved is a common outcome, and it is not by itself evidence that the first diagnosis was wrong.

This is the presentation in which the third molar is genuinely the culprit, and it has a specific anatomy behind it. A lower wisdom tooth that has broken partly through the gum keeps a flap of tissue — the operculum — lying over part of its crown, with a pocket underneath that no toothbrush reaches. Food and bacteria collect in that pocket. The gum swells, and once it has swollen, the upper wisdom tooth starts biting into it every time the jaw closes, which keeps the cycle running.

The pain is at the very back of the lower gum, behind the last tooth you can identify, and you can usually touch the sore spot with a fingertip or find it with the tip of your tongue. There is often a foul taste or odour that a rinse shifts for an hour and no longer. Swallowing may be uncomfortable on that side. Opening may be restricted, because the muscles that close the jaw sit directly over the inflamed tissue and object to being stretched.

What separates pericoronitis from toothache is that the sore structure is gum, not tooth. Cold water on the tooth itself does not usually provoke it. Pressing the gum flap does. And it recurs, because the anatomy that produced it does not change between episodes — an episode that settles with rinsing has settled the inflammation, not the pocket.

What is done about it

An acute episode is managed by cleaning under the flap and irrigating the pocket. It is uncomfortable while it is being done. It clears the debris driving the current episode; it does not alter the anatomy that produced it. Antibiotics are reserved for swelling that has spread beyond the gum, a temperature, or a medical history that makes a spreading infection more consequential. They do not clean the pocket and they are not a treatment for the tooth. Where an upper wisdom tooth is biting into the flap, removing that upper tooth alone sometimes settles the situation, and it involves less surgery than removing the lower one.

After the acute episode has quietened, there is a separate decision about whether the lower tooth stays. A first episode is not automatically a reason to operate. Repeat episodes usually are, because the pocket does not resolve between them. That conversation is held against a radiograph showing the tooth's angle, its depth in bone, and its relationship to the nerve canal — see the article on what impaction means for how position changes the operation.

This is the cause most often mistaken for a wisdom tooth, and the mistake is understandable: the second molar is the tooth immediately in front, the pain is in the same square inch of jaw, and many people in their twenties have an impacted third molar sitting on a nearby radiograph to blame it on.

Where a wisdom tooth is tipped forward into the second molar, the back surface of that second molar is a plaque trap that no brush reaches and floss cannot pass. Decay starts below the contact point, which is also where it is hardest to see on a film taken at the wrong angle. By the time it produces symptoms it is often already deep.

How the tooth tells you which stage it is at

A sensitive tooth reacts sharply to cold and stops within a second or two of the cold being removed. That is a nerve that is irritated and can recover. A tooth whose pain lingers for thirty seconds or a minute after the cold has gone, or which starts aching on its own, or which wakes you at night, has inflammation inside the pulp that generally does not settle by itself. Pain that is provoked by heat and relieved by holding cold water against the tooth is a specific finding rather than a preference, and it is worth reporting in exactly those words.

Once the pulp has died and the infection has reached the tip of the root, the pain changes character again: it becomes precisely localisable, the tooth is tender when tapped, it feels raised in the bite, and lying flat makes it worse. A tooth that could not be identified the week before is usually identifiable at this stage.

The crack that does not show on a film

A cracked tooth has its own signature: pain on releasing a bite rather than on making it. Biting on something firm wedges the crack open, and the sharp jolt arrives as the pressure comes off and the segments spring back together. It is often intermittent, often worse on one particular food, and often cold-sensitive. A crack running through enamel and dentine is frequently invisible on any radiograph, which is why a clear x-ray does not rule this out. It is found with a bite stick tested cusp by cusp, with transillumination, and sometimes only by removing an existing filling and looking underneath it.

All of these are settled by a general dentist, using tests that an assessment of a wisdom tooth does not include: cold testing each tooth in the quadrant, tapping, a bite stick, probing the gum around each tooth, and a periapical radiograph aimed at the root tips. A recently placed filling or crown that sits high in the bite belongs in the same list, and is corrected by adjusting it.

Two different problems are bundled together under "TMJ", and separating them matters because they behave differently and are managed differently. One is the joint itself. The other is the muscles that move it, and muscle is the more common source of the two.

The joint

The temporomandibular joint sits directly in front of the ear canal — put a fingertip in the hollow there and open your mouth, and you will feel the condyle travel forward under it. A disc of cartilage rides on that condyle. When the disc slips forward and snaps back into place as the jaw opens, you get a click on opening and often a second click on closing. A click on its own, without pain and without restriction, is common and is not in itself a reason for treatment.

When the disc slips forward and does not snap back, the jaw runs into it. Opening becomes suddenly limited — often to around two finger-widths — the jaw deviates towards the affected side as it opens, and the click that used to be there disappears. That change, a click that stopped at the same time opening became restricted, is a specific story. In older patients a grating or gravelly sensation rather than a click points at degenerative change in the joint surfaces.

The muscles

The masseter is the pad of muscle you can feel bulge over the angle of the jaw when you clench. The temporalis fans out above and in front of the ear. Both are frequent sources of one-sided jaw pain, and both refer pain convincingly into the teeth. A tender spot in the masseter can produce an ache in the lower molars that feels exactly like toothache, including a degree of tenderness to tapping, in teeth that are entirely healthy.

The pattern that suggests muscle rather than tooth: the pain is diffuse rather than pinpoint, it is worst on waking and eases over the first hour or two, cold and sweet do not provoke it, pressing the muscle reproduces it, and the other side is often tender too even though only one side hurts. Headache at the temple, a tired jaw, and teeth that feel generally sore across a whole quadrant belong to the same picture. Night-time clenching is the usual driver; daytime clenching at a screen, chewing gum, and holding a phone against the shoulder all contribute.

A long dental appointment held with the mouth open is a common trigger, and patients reasonably date the pain to the appointment and assume something was done to a tooth. Muscular pain provoked that way typically starts a day or two later, affects both the joint area and the cheek, and eases over one to two weeks with jaw rest. Where it is not easing by then, it needs looking at rather than waiting out.

First-line management for both groups is conservative and reversible: a soft diet for a period, avoiding wide opening and chewing gum, warmth over the muscle, and gentle opening and closing exercises. Irreversible changes to the bite are not a first step, and a boil-and-bite device bought without assessment can alter the bite if it is worn badly. Where an appliance is appropriate, it is made and fitted after assessment by the clinician managing the problem. This practice treats third molars. Joint and muscle pain is not treated here — it goes to your general dentist, who manages it or refers on to a clinician who handles facial pain.

The trigeminal nerve supplies the teeth, the sinuses, the joint, the muscles of chewing and part of the ear. Pain arriving on shared pathways is poorly localised by the brain, which is why several of the causes below are felt in the teeth and are not in the teeth at all.

Sinus pain referred to the upper teeth

The floor of the maxillary sinus lies directly above the roots of the upper molars, sometimes separated by a thin plate of bone and sometimes by no bone at all. An inflamed sinus therefore produces an ache in the upper back teeth that patients describe as toothache. The clue is that it involves several teeth at once, all upper, all on one side, and no single one of them is convincingly tender when tapped. It is worse on bending forward, walking downstairs, or during descent in an aircraft. A recent cold, a blocked nose on that side, one-sided discharge or a reduced sense of smell complete the picture.

The relationship runs both ways. An infected upper molar can be the source of the sinus infection rather than the victim of it, and the pattern there is one-sided, foul-smelling nasal discharge that does not respond to treatment aimed at the sinus. That needs the tooth and the sinus looked at together, which usually means a dentist and a physician or ENT clinician rather than one or the other.

The ear

A middle ear infection produces pain inside the ear that spreads to the angle of the jaw, often with reduced hearing, sometimes with discharge and fever. It is much more common in children. An outer ear infection hurts when the outer ear is pulled or the tragus is pressed. Both are for a physician.

The more frequent situation is the reverse: ear pain with a normal ear examination. The joint sits immediately in front of the ear canal, and lower molars refer to the ear readily, so an ear that has been examined and found clear points the search back at the jaw and the teeth. This is also the radiation pattern of a dry socket after a lower extraction — pain that had been improving, then sharply worsening around day three to five and spreading towards the ear.

Nerve pain

Trigeminal neuralgia is uncommon, and distinctive when it is described accurately: sudden, severe, electric-shock or stabbing pain lasting seconds, arriving in bursts, triggered by light touch on the face, a cold draught, shaving, brushing the teeth or eating. Between attacks there is usually nothing at all. Dental pain usually carries a background ache and responds to cold and heat; this typically does not. It is often mistaken for a tooth problem, and teeth are sometimes treated before it is recognised. It is managed medically, by a physician or a neurologist.

Salivary glands and the neck

A stone in the submandibular duct produces swelling and pain under the jaw that appears within minutes of starting a meal, or even at the smell of food, and subsides afterwards. That mealtime rhythm is specific enough to be worth reporting exactly as it happens. Muscles in the neck and the upper cervical spine also refer into the jaw angle, particularly where there is a history of neck injury or long hours at a desk.

And the two from the first section that are not dental in any sense: jaw pain with chest pressure or breathlessness, which is a 911 call; and jaw ache brought on by chewing in someone over about 50 with a new headache or scalp tenderness, which needs medical assessment the same day, and an emergency department if vision changes.

Knowing which clinician can answer which question is the practical part of routing yourself correctly, because the tests are not interchangeable.

A general dentist establishes whether a tooth is the source. Cold testing each tooth in the quadrant separately and comparing the response to the same tooth on the other side. Tapping each one. A bite stick applied cusp by cusp to find a crack. Probing the gum around each tooth for a deep pocket. Bitewing radiographs, which show decay under a contact point that a panoramic film does not, and a periapical radiograph aimed at the root tips. That sequence either identifies the tooth or rules the teeth out, and until it has been done, everything else is guesswork.

An oral and maxillofacial surgeon establishes what a third molar is doing and what removing it would involve: the angle, the depth in bone, the state of the tissue over the crown, the condition of the back surface of the second molar, and the relationship of the roots to the inferior alveolar nerve canal. A panoramic radiograph is the starting point. Where the roots appear to cross the canal on that film, a cone-beam scan is taken, because that changes both the consent conversation and sometimes the plan.

A physician examines the ear and the nose, considers whether a sinus infection is bacterial and how long it has run, arranges blood tests where giant cell arteritis is a possibility, and takes over where the pain is neuralgic, cardiac, or part of a wider pain problem.

What imaging cannot answer

A panoramic radiograph will show an impacted wisdom tooth in almost anyone who has one, whether or not it has anything to do with the pain. Finding it is a finding, not a diagnosis. A crack in a second molar is usually invisible on any film. Early decay under a contact point may not show at all on a panoramic image. Muscular pain has no radiographic sign whatsoever, and the position of the joint disc requires MRI, which is rarely needed.

So the sequence matters. The third molar has to be shown to be the source before removing it is the answer to the pain. Where the assessment here shows the pain is coming from the second molar, the joint, the muscles or the sinus, that is what you are told, and you are sent back to your general dentist or on to a physician. A wisdom tooth removed for pain it was not causing leaves the pain where it was and adds a recovery to it.

If you are unsure, a general dentist is the correct default. They can test the teeth, which is the question that has to be answered first in most cases, and they refer onward from there.

This practice treats third molars. That is the scope, and it is the reason the routing above sends most of these presentations elsewhere first.

None of this is treatment. It is what makes the interval tolerable without obscuring the picture for whoever examines you.

• Take over-the-counter analgesia at the dose printed on the packet, at regular intervals rather than waiting for the pain to build. Check it against your other medication and any condition you have. If it is not touching the pain at the labelled dose, that itself is worth reporting.
• Never place an aspirin or any other tablet against the gum next to a sore tooth. It burns the tissue and does nothing for the tooth underneath.
• Cold on swelling, warmth on muscle. Twenty minutes on and twenty minutes off, against the cheek. Heat over a swollen, infected area encourages it to spread.
• For a sore gum flap behind a lower wisdom tooth: rinse with warm salt water — a teaspoon in a cup — several times a day, letting it fall out of the mouth rather than spitting hard, and keep brushing the area with a small-headed brush even though it is tender. The pocket has to be cleaned.
• Chew on the other side, keep the diet soft, and stop chewing gum. If the joint or the muscles are involved, avoid yawning wide, biting into large items, and holding the jaw open for long periods.
• Do not take antibiotics left over from a previous course. A part course masks the signs that an infection is spreading, does nothing about the source, and the infection still needs clearing afterwards.

Keep a short note for a few days: when it hurt, what set it off, how long it lasted, and whether anything looked swollen. Four lines of that is more useful in the chair than a description assembled from memory under a bright light.

Bring an accurate medication list, including supplements and anything bought without a prescription, and any radiographs taken elsewhere in the last six months or the name of the practice that holds them. An examination itself needs no anaesthetic; where an area is acutely inflamed, local anaesthetic is sometimes what makes a thorough examination of it possible. What is used for any procedure that follows is agreed at the consultation, and it depends on the procedure, the number of teeth involved and your medical history.

If the pain changes character while you are waiting — swelling appears, a temperature starts, the altered sensation described in the first section develops, or opening becomes restricted — the interval is over, and the telephone call happens then rather than at the appointment.