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Lateral temporomandibular ligament

The lateral temporomandibular ligament is a crucial supporting structure of the temporomandibular joint (TMJ), stabilizing the joint during mandibular movements. It is a strong, fibrous band that runs from the articular tubercle of the temporal bone to the lateral and posterior aspect of the mandibular neck. Understanding its anatomy, synonyms, and imaging characteristics is essential for accurate diagnosis of TMJ pathology, especially on MRI.

Synonyms:

  • Lateral TMJ ligament

  • External lateral ligament

  • Temporomandibular lateral ligament

  • Lateral ligament of TMJ

Anatomical Description:

  • The lateral temporomandibular ligament is a key extrinsic ligament of the TMJ.

  • Originates at the articular tubercle (root of the zygomatic arch) on the temporal bone.

  • Inserts into the lateral and posterior surface of the neck of the mandible.

  • Functions to prevent posterior and lateral displacement of the mandible, limiting excessive movements.

  • Works together with other ligaments and the joint capsule to stabilize the TMJ during mouth opening and closing.

MRI Appearance:

On Proton Density (PD) Sequence:

  • Appears as a thin, low-signal intensity band adjacent to the lateral aspect of the TMJ capsule.

  • Well delineated against the higher signal intensity of the surrounding soft tissue and fat.

  • Best appreciated in coronal and oblique sagittal planes.

On Short Tau Inversion Recovery (STIR) Sequence:

  • Maintains low signal intensity (dark appearance) due to its dense fibrous composition.

  • Fluid or edema (if present due to injury) will appear hyperintense, providing good contrast for ligament pathology.

  • Useful for detecting subtle injuries, inflammation, or thickening.

On T1-Weighted Sequence:

  • The ligament remains a thin, hypointense (dark) linear structure.

  • Easily identified when surrounded by hyperintense (bright) fat in the preauricular space.

  • Useful for assessing anatomic integrity and relationship to adjacent structures.

MRI images

Lateral Temporomandibular Ligament MRI