CT TM Joint Test

Pain related to temporomandibular joint (TMJ) is common in general public. TMJ disorders are the most common clinical conditions for imaging referrals. The computed tomography plays an important role in the diagnosis of anomalies and pathological conditions of the TMJ, providing a complete visualization of joint region, providing a more accurate diagnosis. For evaluation of the images, it is necessary to have the professional knowledge of sectional anatomy of the joint region, so he can recognize the structural changes. It has been difficult to evaluate the TMJ on conventional radiographs because of overlap by bones of skull base and face. With the advent of multi detector row computed tomography (CT) technology, it has become possible to acquire thin slices and do multiplanar reformatted reconstructions.

You should inform the doctor / radiology center regarding recent illness or medical conditions if you have a history of heart disease, asthma, diabetes, kidney disease, thyroid problems, and iodine or shellfish allergy. Women should always inform the doctor and the Radiology center if they are or may be pregnant. You should remove all the metal objects like keys, coins wallets, cards with magnetic strips, jewellery, hair pins and hearing aid. Change your dress with the hospital gown. You should keep calm as the process is longer. Your weight will be noted by the staff.

Doctors can have a closer look of your soft tissues (such as muscles & ligaments) and can observe if there is inflammation in your joints.

The patient lies supine on the CT table and is instructed not to move or swallow during the scanning process. The scan should start at the level of inferior orbital margin and end at the level of tip of the chin. The scan area must include the external auditory canals. Slice thickness and slice interval for acquisition should be 0.5-1 mm. Sagittal images are reconstructed from the raw data perpendicular to the plane of mandibular condyles as seen on axial plane, and coronal images are reconstructed parallel to the condyles with a slice thickness and inter-slice gap of 2-3 mm.