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Mandible

The mandible, also known as the lower jaw or jawbone, is a critical facial bone that forms the lower part of the skull and houses the lower teeth. It plays a significant role in mastication, speech, and facial structure. MRI is increasingly used to evaluate the mandible and its surrounding structures, offering detailed information about bone marrow, cortical bone, and adjacent soft tissues. Understanding the mandible's appearance on different MRI sequences such as Proton Density (PD), Short Tau Inversion Recovery (STIR), and T1-weighted images is essential for accurate assessment of normal anatomy, trauma, infection, tumors, and inflammatory processes.

Synonyms:

  • Mandibular bone

  • Jawbone

  • Lower jaw

  • Inferior maxilla

MRI Appearance:

1. Proton Density (PD) Sequence:

  • Provides intermediate contrast between bone marrow and surrounding soft tissues.

  • Marrow appears with intermediate signal intensity, depending on the balance of fat and cellular content.

  • Useful for assessing subtle marrow changes and bone marrow edema.

  • Cortical bone appears as a low-signal (dark) rim due to its low proton density.

2. STIR (Short Tau Inversion Recovery) Sequence:

  • Highly sensitive for detecting fluid and edema.

  • Bone marrow edema and inflammation in the mandible appear as high signal (bright areas).

  • Normal fatty marrow is suppressed and appears dark.

  • Essential for identifying early osteomyelitis, trauma, or marrow infiltration.

3. T1-Weighted Sequence:

  • Provides excellent anatomical detail.

  • Normal bone marrow appears hyperintense (bright) due to high fat content.

  • Cortical bone is hypointense (dark).

  • Pathological changes such as tumor infiltration, infection, or edema cause a drop in marrow signal, appearing hypointense compared to normal marrow.

  • Useful for evaluating anatomy, fat content, and detecting lesions.

MRI images

Mandible mri

CT VRT 3D image

Mandible 3D image

CT images

Mandible CT axial Anatomy, Location and Imaging Appearance -img-00000-00000