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Supraorbital margin

The supraorbital margin is the superior bony rim of the orbit, forming part of the frontal bone. It defines the upper boundary of the orbital opening and serves as an important anatomical landmark in craniofacial anatomy, radiology, ophthalmology, and maxillofacial surgery.

It commonly contains the supraorbital notch or foramen, which transmits neurovascular structures to the forehead and scalp.

Synonyms

  • Supraorbital rim

  • Upper orbital margin

Location

  • Located at the superior border of the orbital opening

  • Formed by the frontal bone

  • Extends from the medial orbital margin to the lateral orbital margin

  • Inferior to the frontal bone squama

  • Superior to the orbital cavity and globe

  • Continuous laterally with the zygomatic process of the frontal bone

Anatomical components

  • Frontal bone (orbital part)

  • Supraorbital notch or supraorbital foramen (variant anatomy):

    • May appear as a notch, partial foramen, or complete foramen

  • Associated landmarks:

    • Frontal tubercle (superolateral)

    • Glabella (medial reference point)

  • Overlying soft tissues:

    • Eyebrow

    • Forehead scalp

    • Frontalis muscle

Relations

Superiorly:

  • Forehead scalp and subcutaneous tissues

  • Frontalis muscle

Inferiorly:

  • Orbital contents

  • Superior rectus and levator palpebrae superioris (deep)

Medially:

  • Glabella

  • Frontal sinus region

Laterally:

  • Zygomatic process of the frontal bone

  • Lateral orbital rim

Posteriorly:

  • Anterior cranial fossa (orbital roof)

Contained / transmitted structures

  • Supraorbital nerve

  • Supraorbital artery and vein

  • Exit point for forehead and scalp neurovascular supply

X-ray appearance

Skull and orbital radiographs:

  • Supraorbital margin: Smooth, curvilinear dense bony rim

  • Supraorbital notch/foramen: Small focal indentation or round lucency

  • Symmetry: Typically symmetric bilaterally

  • Orbital outline: Well-defined superior orbital contour

CT appearance

Non-contrast CT:

  • Supraorbital margin: Sharp cortical bone forming the superior orbital rim

  • Notch/foramen: Clearly defined cortical interruption

  • Frontal sinus relation: Visible medially above the orbit

Post-contrast CT:

  • Bone: No enhancement

  • Supraorbital vessels: May enhance within the notch or foramen

3D CT VRT appearance

Volume-rendered technique (VRT):

  • Supraorbital rim: Smooth, continuous superior orbital arch

  • Notch or foramen: Easily appreciated as a focal defect or opening

  • Bilateral comparison: Helpful for detecting asymmetry or variant anatomy

  • Surgical planning: Useful in craniofacial and orbital procedures

MRI appearance

T1-weighted images:

  • Bone cortex: Low signal intensity

  • Marrow (frontal bone): Intermediate signal

  • Supraorbital neurovascular bundle: Small linear structures within the notch/foramen

T2-weighted images:

  • Bone: Low signal

  • Adjacent soft tissues: Intermediate-to-high signal

  • Orbital contents: Normal signal characteristics

CT VRT 3D image

Supraorbital margin

CT image

x ray Supraorbital margin