The temporomandibular joints (TMJ) are the two joints connecting your jawbone to your skull, located in front of each ear. These joints allow for complex movements, including opening and closing the mouth, chewing, and speaking. When issues arise with these joints or the surrounding muscles, it can lead to discomfort, pain in the jaw, face, or ear, and sometimes clicking or popping sounds during jaw movement. Magnetic Resonance Imaging (MRI) is a diagnostic tool used to examine the TMJ and identify the underlying causes of discomfort.
Understanding MRI for TMJ
An MRI of the temporomandibular joint evaluates the joint’s soft tissues. It provides detailed images that other techniques, like X-rays, might not capture. The MRI can reveal specific details about the articular disk, a small, shock-absorbing structure within the joint, including its position, shape, and movement.
It also identifies inflammation within the joint, such as synovitis or capsulitis, and detects joint effusion (fluid buildup). An MRI can also show degenerative changes in the bones, such as erosion or bone marrow edema. By visualizing these structures, MRI helps differentiate between various TMJ issues, from disc displacement to arthritis, guiding appropriate treatment decisions.
How to Prepare for an MRI
Preparing for a TMJ MRI involves steps to ensure safety and image quality. Inform the medical staff about any metal implants in your body, such as pacemakers, surgical clips, or cochlear implants, as these can be affected by the MRI’s strong magnetic field. While most modern dental implants are safe, notify staff about any dental materials that might cause image distortions.
Remove all metallic items before the scan, including jewelry, watches, hearing aids, hairpins, and any clothing with metal fasteners. Wearing comfortable, loose-fitting attire without metal is recommended. If you experience claustrophobia, inform the medical team; they may offer strategies to help you relax or a mild sedative.
What Happens During the Scan
During a TMJ MRI, you will lie on a movable table that slides into a large, tube-shaped machine. The machine produces loud thumping, banging, and humming noises, so earplugs or headphones are provided to reduce the sound. Remain perfectly still throughout the procedure to ensure clear images.
A TMJ MRI typically takes 30 to 60 minutes, though duration can vary. Images are usually taken with your mouth both closed and open, sometimes with a bite block.
In some instances, a contrast dye may be administered through an intravenous (IV) line; this dye helps highlight specific areas like inflammation or potential tumors, though it is not always necessary. A technologist will communicate with you via an intercom system, ensuring your comfort and addressing any concerns.
After Your TMJ MRI
Following your TMJ MRI, you can resume normal activities immediately, unless sedated, in which case transportation home is needed. The MRI images are sent to a radiologist, a medical doctor specializing in interpreting diagnostic scans.
The radiologist analyzes the images and prepares a report. This report is sent to your referring doctor, usually within a few days. Your doctor will discuss the findings with you during a follow-up appointment, explaining the results and outlining the next steps for your diagnosis and treatment plan.