What is Temporomandibular Joint Disorder (TMJ)?

Temporomandibular Joint disorder (TMJ or TMJD) is a pain disorder associated with the jaw joint. The condition can present in numerous ways. It can cause significant pain which can interfere with your daily life. The most common symptoms are clicking and popping of the jaw, ear pain and headaches (most often described as tension headaches).

Looking at each of the common symptoms in depth can explain what is happening to create them:

Clicking, popping and lockjaw

There is a disc in the joint that cushions it during movement. The disc prevents bone-against-bone contact during function. Over time this would cause the bone of the joint to wear down, like rubbing two rocks against each other. The disc glides along the joint as it’s moving. This is a real-time MRI of the joint in function showing the disc moving along normally. (This disc is the dark grey above the condyle–the part that looks like a curved matchstick.)

The disc can sometimes pop out of position and then pop back into position. This is the clicking and popping sound that you can hear and feel when the jaw is opening or closing.

Occasionally the disc will get stuck in front of the joint or behind the joint. The disc being in the way prevents the jaw from opening or closing. This is what causes lockjaw.

What causes the disc to get out of whack in the first place?

The disc is connected to the jawbone through a few muscles and ligaments. Chronic tension on the muscles and muscle cramps can pull the disc out of position.

The cause of chronic muscle tension can be from clenching or grinding due to stress, a sleep disorder like sleep apnea, or misalignment of the teeth.

Tension Headaches and Ear Pain

Pain is the most common and debilitating reason people choose to look into treatment options.

There can be many factors of TMJ that result in pain. The most common is the ‘tension headache’.

Many people describe tension headache as feeling like having your head being squeezed in a vise. It is commonly a persistent headache that occurs frequently throughout the day and more than several times per month.

Posture and overuse of the muscles, due to clenching or grinding, are the main culprits.

In the illustration above, you can see the muscles and ligaments that are all attached to the disc. In this illustration, the disc is the white part above the condyle. The muscles are the pink lined areas and the ligaments are the white ends of the muscles.

You can see as well how some of the muscles and ligaments attach behind the condyle.

The dark hole that’s there, above the sharp pointed bone (the styloid process) is the ear canal.

You could see that if these muscles and ligaments get stressed out and inflamed, they can pull on the ear canal itself, causing ear pain.

The pain feels like it’s coming from your ear, but the cause of the pain is from the temporomandibular joint disorder.

Dizziness, ringing in the ear and hearing loss can all be associated with TMJD.

Limited Jaw Movement

Changes in the range of motion of your jaw can be serious and take a long time to resolve.

If the muscles are chronically tired and then they’re asked to do even more, they can get overwhelmed and quit for a while.

If you imagine you spent all day every day lifting weights, and then had to run a marathon, your body would be unhappy to move for a while afterwards.

Resting and relaxing the muscles of your face and head is much harder because you still have to eat, breathe and talk.

Facial Pain

The chewing muscles are all interconnected around the temporomandibular joint (TMJ).

When one muscle is stressed, they can pull on each other as well as the joint itself and cause all sorts of aches and pains in the head, neck and face.

There are nerves that run closely underneath the muscles as well that can be pinched and restricted by chronically tensed muscles.

Here you can see all of the muscles, nerves and some arteries that run through the face.

All of these things are very close to each other, and close to other important anatomic structures.

Pain in this region can send signals far away from the source of the problem.