CT TMJ (Jaw Joint):what to expect

Your doctor may request a CT TMJ scan for:

• Evaluating jaw fractures (such as condylar fractures) after facial trauma.
• Investigating severe pain, clicking, or difficulty opening your mouth.
• Checking for arthritis or degenerative changes in the jaw joint.
• Assessing benign bone tumors (like osteochondromas) or cysts in the jaw.
• Planning for corrective jaw surgery.

No, it is a straightforward scan, though your doctor might also order an MRI if they suspect the pain is coming from the soft tissue disc rather than the bone.

The scan itself does not usually hurt. If you have a jaw injury, holding your mouth open for some images may be uncomfortable; tell the radiographer if pain is worsening.

Usually, no special preparation is needed.

Yes, you can usually eat and drink normally before this scan, as contrast dye is rarely required for looking at the jawbones.

You must remove necklaces, earrings, hearing aids, hairpins, and removable dental work (like dentures or retainers) so they do not interfere with the images.

The CT scanner looks like a large, wide, circular ring. You lie on a narrow table that gently moves your head into the center while images are captured.

You will lie flat on your back with your head supported to keep it perfectly still. The table moves through the scanner while multiple images are taken. You may be asked to hold your breath briefly. The Radiographer may also take two sets of images: one with your mouth closed, and one with your mouth open, to see how the joint moves.

The scan itself usually takes 5 to 10 minutes.

Contrast is rarely used for a standard TMJ scan. However, if your doctor is looking for an infection, an abscess, or a specific type of tumor, they may use an IV contrast dye to highlight the soft tissues.

If contrast is used, most people tolerate it well. Allergic-like reactions can occur and severe reactions are rare. Kidney-function testing is based on risk factors and local policy; report a previous iodinated-contrast reaction, acute kidney injury, or severe kidney disease.

You can resume your normal activities immediately.

CT uses ionising radiation. Dose depends on the field, scanner, and protocol, and the examination should be justified for a bone or surgical-planning question that CT can answer better than a lower-dose test.

Tell the clinician and CT team if you are pregnant or could be pregnant. Fetal exposure from a correctly performed focused jaw CT is expected to be very low because the pelvis is outside the beam. The scan still requires justification and optimisation; MRI may be preferable for joint-disc soft tissue.

• RadiologyInfo: Head CT
• FDA: Computed tomography benefits and risks

A CT TMJ scan is a quick, painless, and effective way to assess the bony structures of your jaw. It gives your doctor the exact details needed to treat your jaw pain and restore comfortable movement.