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Topic

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Bony nasal septum

The bony nasal septum forms the posterior and inferior rigid component of the nasal septum, dividing the nasal cavity into right and left halves. It provides structural support to the nasal cavity and serves as an important anatomical landmark in otolaryngology, maxillofacial surgery, and head and neck imaging.

It is distinct from the cartilaginous nasal septum and is commonly evaluated on radiographs and CT for alignment, integrity, and anatomical variation.

Synonyms

  • Osseous nasal septum

  • Bony septum of the nose

Location

  • Situated in the midline of the nasal cavity

  • Forms the posterior and inferior portion of the nasal septum

  • Anterior to the nasopharynx

  • Inferior to the nasal bones

  • Superior to the hard palate

  • Medial to the nasal cavities

Anatomical components

  • Vomer:

    • Forms the posteroinferior part of the bony septum

  • Perpendicular plate of the ethmoid bone:

    • Forms the posterosuperior part of the bony septum

  • Articulations:

    • Inferiorly with the maxilla and palatine bones

    • Superiorly with the ethmoid bone

    • Anteriorly with the septal cartilage

Relations

Anteriorly:

  • Septal cartilage

  • Nasal vestibule

Posteriorly:

  • Choanae

  • Nasopharynx

Superiorly:

  • Cribriform plate of the ethmoid

  • Nasal roof

Inferiorly:

  • Hard palate

  • Maxillary and palatine crests

Laterally:

  • Nasal cavities

  • Inferior and middle turbinates

Developmental anatomy

  • Develops from ossification of the ethmoid and vomer

  • Perpendicular plate ossifies from the ethmoid cartilage

  • Vomer ossifies from paired centers that fuse in the midline

  • Growth continues through childhood with integration of septal cartilage

X-ray appearance

Skull or paranasal sinus radiographs:

  • Bony septum: Thin vertical radiopaque line in the midline

  • Vomer: Inferior radiodense component

  • Alignment: May appear straight or deviated

  • Limitations: Overlap of facial structures may obscure details

CT appearance

Non-contrast CT:

  • Bony septum: High-attenuation osseous structure in the midline

  • Vomer: Dense inferior component

  • Perpendicular plate: Thin superior bony plate

  • Relationship: Clearly defined relative to turbinates and nasal cavity walls

Post-contrast CT:

  • Bony septum: No enhancement

  • Adjacent mucosa: May enhance normally

3D CT VRT appearance

Volume-rendered technique (VRT):

  • Septal contour: Midline vertical bony plate

  • Symmetry: Clearly demonstrates alignment and deviation

  • Articulations: Visualizes junctions with maxilla, palatine bones, and ethmoid

  • Clinical utility: Useful for preoperative planning and anatomical orientation

MRI appearance

T1-weighted images:

  • Bony septum: Very low signal intensity

  • Adjacent marrow (if visible): Low to intermediate signal

  • Septal cartilage: Intermediate signal anteriorly

T2-weighted images:

  • Bone: Low signal

  • Surrounding nasal mucosa: Intermediate-to-high signal

CT image

ct Bony nasal septum anatomy image -img-00000-00000

X-Ray image

x ray Bony nasal septum

CT VRT 3D image

Bony nasal septum