How the jaw joint works

The jaw joint does two things at once. It rotates like a hinge for the first inch or so of opening, then slides forward down a slope in the skull for the rest of the range. Between the ball and socket sits a small disc that moves with the jaw and cushions the load.

You have two of these joints joined by one rigid bone, so neither one moves entirely on its own. That's one reason a problem on one side often produces symptoms on both, and why the muscles running into the temple and down the neck are frequently involved. Symptoms on one side only are also common, and either pattern deserves an examination.

The disc is where the noises usually come from. If it slips forward of the ball and is recaptured as you open, you get a click. If it stays out of place, the jaw may not open as far. Clicking on its own, with no pain and no limit on opening, is common and often needs no treatment at all.

Common symptoms

Jaw problems can refer pain to the ear, the head and the neck, so the symptoms are not always obviously dental.

  • Morning headaches. A dull ache in the temples on waking, sometimes a band around the head. It often comes from muscles that have been working overnight.
  • Jaw fatigue and soreness. Aching in front of the ear or along the angle of the jaw, often worse after chewing something tough like steak or a bagel.
  • Clicking, popping or grating. Noise on opening or closing. Grating tends to indicate more than clicking does.
  • Locking. A jaw that won't open past about two fingers wide, or one that opens and won't close. If this happens, please call us promptly.
  • Ear symptoms with a normal ear exam. Pain, fullness or ringing when nothing was found wrong with the ear itself. The joint sits directly against the ear.
  • Worn, cracked or sensitive teeth. Flat shiny facets, chipped edges, cracked fillings, teeth that ache in the morning. Teeth grinding is often first noticed at an exam.

What causes it

A great deal of jaw pain turns out to be muscular. Clenching and grinding load the chewing muscles for long stretches, the muscles become tender and shortened the way any overworked muscle does, and the pain can spread into the temple, the ear and the neck. The joint itself is often healthy.

Grinding mostly happens during sleep and isn't under conscious control. Daytime clenching is a habit that tends to accompany stress or concentration, and it often goes unnoticed until someone asks about it. Gum chewing, nail biting, chewing on one side, an old injury and whiplash can all contribute. Arthritis and damage inside the joint account for a smaller share of cases.

Dental causes exist, though they are less common than often assumed. A filling or crown left slightly high, a tooth lost and never replaced so that the bite collapsed on that side, or contacts that make the jaw slide sideways to close can all keep muscles working. Grinding is also associated with disordered breathing during sleep, which is why we ask about snoring. See sleep apnea.

How the condition is evaluated

The examination consists mainly of questions and gentle pressing. We turn to imaging when the history calls for it rather than as a first step.

  1. History

    We ask when it started, what makes it worse, whether it wakes you, about previous injuries, and what you've already tried. Pain that is worst in the morning and pain that is worst in the evening point in different directions.

  2. Palpation

    We press the muscles in the cheek and temple, the muscles under the jaw, and the joint itself, and ask what reproduces your pain. Finding the exact spot often tells us more than imaging would.

  3. Range of motion

    How far you open, measured in millimeters, whether the jaw deviates to one side on the way, and where in the arc a noise happens. Repeat measurements show us whether anything is improving.

  4. The bite and the teeth

    We look for wear facets, cracks, loose teeth, high restorations and missing teeth, and check whether the teeth meet evenly across both sides.

  5. Ruling out other causes

    We take x-rays when the history suggests joint change, an abscessed tooth or a fracture. Not all jaw pain comes from the joint. Dental infection, sinus problems and nerve pain can all resemble it, and anything that doesn't fit the clinical picture is referred.

Conservative treatment, including a night guard

Many cases settle with measures that change nothing irreversibly. They tend to work better in combination than one at a time.

Rest the jaw, with heat or cold
Eat soft food for a couple of weeks, cut into small pieces. Skip gum, chewy bread and ice, and support your chin when you yawn. Moist heat tends to suit muscular pain, and cold tends to suit an acutely inflamed joint.
Habit awareness
Keep the teeth apart and the lips together. The teeth only need to touch during eating. Symptoms often coincide with stressful periods, and many people who clench during the day find the habit easier to change once they begin noticing it.
Physical therapy
Stretching, posture work and manual therapy for the jaw and neck. For persistent muscular cases this often helps considerably, and we're glad to provide a referral.
A night guard
A custom hard guard worn while you sleep. It protects the teeth from grinding and gives the muscles a chance to settle. It doesn't stop the grinding itself, and a soft drugstore tray can make clenching worse for some people. Protecting teeth now is usually easier than restoring them later with crowns.
Dental contributors, where they apply
Adjusting a filling or crown that sits high, restoring a broken-down tooth, or replacing a missing tooth so that the bite is supported. These are small and specific adjustments rather than a rebuild of the bite.

Questions about jaw pain

Will my jaw clicking get worse?

Often it doesn't. Clicking that doesn't hurt, doesn't limit opening and has been stable for years is usually watched rather than treated. Clicking that is new or painful is a good reason to come see us.

Does TMJ go away on its own?

Many episodes settle within weeks, particularly after a stressful period or a long dental appointment. Symptoms that last beyond a few weeks, or that keep returning, deserve an examination, and we're happy to take a look.

Do I need an MRI?

Not usually. Imaging helps when the history points to damage inside the joint, when a lock doesn't resolve, or when conservative treatment hasn't worked. Much muscular jaw pain is diagnosed by examination alone.

Can a night guard from the pharmacy work?

It may be adequate for a short period. Over the longer term a boil-and-bite tray tends to fit loosely, can allow teeth to move, and is often too soft to do the job well.

Is my jaw pain caused by a bad bite?

Sometimes a high filling or a collapsed bite contributes, which is why we examine the bite. Often it proves to be a contributing factor rather than the main cause, and that difference determines whether treatment stays small and reversible or needs to go further.