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Topic

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Temporomandibular joint

The temporomandibular joint (TMJ) is a complex synovial joint connecting the mandible (lower jaw) to the temporal bone of the skull. It is essential for jaw movement, including chewing, speaking, and yawning. TMJ disorders are a common cause of facial pain and dysfunction, making MRI an invaluable tool for detailed assessment of the joint’s anatomy, articular disc, and surrounding soft tissues. MRI, especially with PD, STIR, and T1 sequences, provides superior soft tissue contrast, allowing evaluation of disc position, joint effusion, inflammation, and degenerative changes.

Synonyms:

  • TMJ (Temporomandibular Joint)

  • Mandibular condyle joint

  • Temporomandibular articulation

  • Craniomandibular joint

MRI Appearance of the TMJ:

1. Proton Density (PD) Sequence:

  • Provides high soft tissue contrast and excellent visualization of the articular disc and joint space.

  • Normal TMJ disc appears as a thin, biconcave, hypointense structure between the mandibular condyle and temporal bone.

  • Useful for detecting subtle disc displacement or morphological changes.

2. Short Tau Inversion Recovery (STIR) Sequence:

  • Highly sensitive for fluid and edema due to fat suppression.

  • Normal joint shows low signal in the disc, high signal in joint fluid.

  • Accentuates joint effusion, synovitis, bone marrow edema, and inflammatory changes in the condyle or surrounding soft tissues.

3. T1-Weighted Sequence:

  • Optimal for evaluating osseous structures, bone marrow, and the articular disc.

  • Normal TMJ disc appears as a low-signal structure; mandibular condyle and articular eminence demonstrate high signal (fatty marrow).

  • Detects chronic degenerative changes, fatty infiltration, and tumors.

MRI images

Temporomandibular joint mri iamge

CT image

Temporomandibular joint CT

CT VRT 3D image

Temporomandibular joint 3D