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Nasal bones

The nasal bones are two small, rectangular, paired bones forming the bridge of the nose. They articulate with one another in the midline and contribute significantly to the upper third of the nasal dorsum, providing shape, contour, and structural support to the external nose.

They articulate superiorly with the frontal bone, laterally with the frontal processes of the maxilla, and inferiorly with the upper lateral cartilages, forming the osseocartilaginous junction. The nasal bones help protect the upper nasal cavity and support the attachment of nasal soft tissues.

Synonyms

  • Nasal bridge bones

  • Os nasale

  • Upper nasal vault

Location and Structure

  • Position: Midline bones forming the upper third of the external nose.

  • Shape: Rectangular, thin, slightly curved plates.

  • Surfaces:

    • External surface: Convex, smooth, forms the nasal dorsum.

    • Internal surface: Concave, forms part of the nasal cavity roof.

  • Borders:

    • Superior: Articulates with frontal bone (nasofrontal suture).

    • Inferior: Connects to upper lateral cartilage.

    • Medial: Articulates with opposite nasal bone.

    • Lateral: Articulates with frontal process of maxilla.

Relations

  • Superiorly: Frontal bone and glabella.

  • Inferiorly: Upper lateral nasal cartilages.

  • Laterally: Frontal process of the maxilla.

  • Posteriorly: Nasal part of the frontal bone and nasal septum cartilage.

  • Anteriorly: Nasal skin and subcutaneous soft tissue.

Attachments

  • Upper lateral nasal cartilages attach inferiorly at the osseocartilaginous junction.

  • Procerus muscle attaches onto the lower part of the nasal bones.

  • Nasal periosteum blends with cartilaginous perichondrium forming a continuous structural support layer.

Function

  • Provides rigid support for the nasal dorsum and upper nasal vault.

  • Forms a protective osseous covering for the upper nasal cavity.

  • Helps define the aesthetic nasal profile and facial contour.

  • Serves as an anchor point for nasal soft tissues and cartilage.

MRI Appearance

T1-weighted images:

  • Bone cortex: Dark (low signal).

  • Marrow (minimal in nasal bones): May show intermediate-to-bright signal due to small fatty marrow regions.

  • Surrounding soft tissues: Intermediate signal.

  • Cartilage below nasal bones: Intermediate-to-low signal intensity.

T2-weighted images:

  • Bone cortex: Dark (very low signal).

  • Marrow space: Slightly bright, depending on fatty content.

  • Adjacent soft tissue and mucosa: Bright to intermediate signal.

  • Upper lateral cartilage region: Intermediate signal adjacent to inferior nasal margin.

STIR:

  • Bone cortex: Dark.

  • Marrow region: Intermediate-to-dark signal in normal conditions.

  • Surrounding soft tissues: Intermediate with fat suppression.

  • Nasal mucosa: Mildly hyperintense due to normal moisture content.

T1 Fat-Saturated Post-Contrast:

  • Cortical bone: No enhancement.

  • Periosteum and soft tissues: Mild homogeneous enhancement.

  • Nasal mucosa: Displays expected vascular enhancement.

CT Appearance

Non-Contrast CT:

  • Bone: High-density thin cortical plates forming nasal dorsum.

  • Contours: Easily visualized, allowing clear assessment of nasal profile and osseocartilaginous transition.

  • Sutures: Nasofrontal and internasal sutures sharply defined.

  • Cartilage inferiorly: Appears as soft tissue density adjacent to the lower nasal bone margin.

Post-Contrast CT (standard):

  • Bone: No enhancement.

MRI images

Nasal bones coronal mri image

MRI images

Nasal bones MRI axial image