US Vs MRI in Diagnosis of TMJ Internal Derangement

Temporomandibular disorders (TMDs) are conditions that affect the temporomandibular joint (TMJ), often leading to pain and dysfunction. The most common cause of TMJ problems is internal derangements.

The term "internal derangements" refers to conditions with the articular disc displaced from its original position on the mandibular condyle.

Disc displacement may occur anteriorly, anterolaterally, laterally, anteromedially, medially, or posteriorly, but the latter is very rare.

Anterior disc displacement (ADD) is the most common ID condition and is usually divided into two categories: with reduction and without reduction. Each category has special features during closed and opened mouth positions. Therefore, the examination should include both positions.

Clinical examination alone isn't enough to diagnose TMJ problems, therefore additional imaging tests are often needed.

Magnetic resonance imaging (MRI) is the gold standard modality, however because of its limited availability, long scan time, and high cost, it is difficult to use MRI as a screening technique.

Ultrasound (US) has been recommended as an alternate diagnostic imaging modality for TMJ problems as it is less costly, non-invasive and capable of providing real-time imaging, presents an alternative diagnostic tool. Thus, the articular disc may be seen as the patient is opening and closing their mouth

Inclusion criteria

• Patients showing signs of TMJ internal derangements

Exclusion criteria

• contraindications for MRI such as claustrophobia, heart pacemaker and metallic foreign body carriers.
• patients in which the misaligned images or distortions due to motion artifacts made the interpretation of the MRI unreliable.
• Previously operated TMJ.