Topics

Topic

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Glabella

The glabella is a smooth, slightly depressed or flattened midline bony prominence of the frontal bone located between the superciliary arches, just above the root of the nose. It represents an important surface anatomical landmark of the skull and face and corresponds internally to the frontal sinus region (when present) and the anterior cranial fossa floor.

The glabella is clinically significant in anthropometry, forensic identification, facial aesthetics, neurosurgical planning, and trauma assessment. It is also a standard reference point in cephalometric analysis and craniofacial measurements.

Synonyms

  • Interbrow prominence

  • Midfrontal surface landmark

Location and Structure

  • Position: Midline frontal bone between the eyebrows, superior to the nasion

  • Bone: Frontal bone (squamous part)

  • Surface contour: Smooth, rounded, and non-articular

  • Internal relation: Lies anterior to the frontal sinus (if pneumatized)

  • Development: Derived from membranous ossification of the frontal bone

Relations

  • Superiorly: Frontal squama

  • Inferiorly: Nasion and nasal bones

  • Laterally: Superciliary arches

  • Posteriorly: Anterior cranial fossa and frontal lobes

  • Anteriorly: Skin, subcutaneous tissue, and procerus muscle

Attachments

  • Muscular:

    • Procerus muscle

    • Frontal belly of occipitofrontalis (via galea aponeurotica)

  • Soft tissue: Overlying skin and subcutaneous connective tissue

Function

  • Surface landmark: Used as a reference point in radiology, anthropology, and surgery

  • Structural role: Contributes to the contour and strength of the frontal bone

  • Facial aesthetics: Influences facial profile and midface harmony

Clinical Significance

  • Important reference in cephalometric analysis

  • Key landmark in facial trauma evaluation

  • Used in forensic identification and sex estimation

  • Entry point consideration in certain neurosurgical approaches

MRI Appearance

T1-weighted images:

  • Cortical bone: Very low signal (black)

  • Diploic marrow: Bright signal due to fatty marrow

  • Overlying soft tissues: Intermediate signal

  • Frontal sinus (if present): Low signal (air-filled cavity)

T2-weighted images:

  • Cortical bone: Low signal

  • Diploic marrow: Bright, slightly less intense than on T1

  • Soft tissues: Intermediate-to-bright signal

  • Frontal sinus: Signal void due to air

STIR:

  • Bone cortex: Dark

  • Normal marrow: Intermediate-to-dark signal

  • Soft tissues: Intermediate signal with clear fat suppression

T1 Fat-Saturated Post-Contrast:

  • Bone cortex: No enhancement

  • Diploic marrow: Mild homogeneous enhancement

  • Overlying soft tissues: Uniform enhancement reflecting normal vascularity

CT Appearance

Non-Contrast CT:

  • Cortical bone: High attenuation, sharply defined

  • Diploic space: Lower attenuation compared to cortex

  • Frontal sinus (if present): Air-filled hypodense cavity posterior to glabella

  • Surface contour: Smooth, symmetric midline prominence

Post-Contrast CT (standard):

  • Bone: No enhancement

  • Diploic marrow: Mild enhancement

  • Soft tissues: Homogeneous enhancement without focal abnormality

X-Ray Appearance

  • View: Lateral skull or frontal skull radiograph

  • Appearance: Smooth anterior frontal contour at the midline

  • Cortex: Dense radiopaque frontal bone

  • Frontal sinus: Radiolucent air space posterior to glabella when present

MRI image

Glabella MRI anatomy labelled image-img-00000-00000

CT image

Glabella CT anatomy labelled image-img-00000-00000