Nasal Bones

1. Overview

The nasal bones are two small, oblong bones that form the bridge of the nose. These paired bones are part of the facial skeleton and play a key role in shaping the nose and supporting the cartilaginous structures of the nasal cavity. Though small in size, they contribute to both the aesthetic and functional architecture of the upper midface.

2. Location

The nasal bones are located in the upper-middle part of the face, at the superior aspect of the nose:

• Medially: They articulate with each other at the midline via the internasal suture.

• Superiorly: Articulate with the frontal bone at the frontonasal suture.

• Laterally: Articulate with the frontal processes of the maxillae.

• Inferiorly: Connect to the upper lateral cartilages of the nose.

3. Structure

Each nasal bone is a small, flat, rectangular bone with compact bone externally and cancellous bone internally:

• External surface: Convex and covered by the nasal part of the procerus and nasalis muscles.

• Internal surface: Concave and contributes to the formation of the nasal cavity roof.

• Articulations: Each nasal bone articulates with four bones:

  • Opposite nasal bone (medially)

  • Frontal bone (superiorly)

  • Maxilla (laterally)

  • Perpendicular plate of the ethmoid bone (deeply)

4. Function

The nasal bones serve multiple structural and protective roles:

• Form the nasal bridge: Provide bony structure to the upper part of the nose.

• Support cartilage: Act as an anchoring site for the upper lateral cartilages and septal cartilage.

• Protect internal structures: Shield the upper nasal cavity and underlying neurovascular structures from trauma.

• Shape facial profile: Contribute significantly to nasal contour and overall facial symmetry.

5. Physiological role(s)

Although non-movable, the nasal bones support various physiological functions through their structural contributions:

• Respiration: Help form the rigid framework that maintains nasal airway patency.

• Olfaction: Indirectly support the nasal cavity which houses olfactory epithelium, crucial for the sense of smell.

• Facial expression: Serve as attachment points for muscles involved in expressions like flaring the nostrils or wrinkling the nose.

• Speech resonance: Contribute to shaping the nasal cavity, affecting voice resonance and clarity.

6. Clinical Significance

The nasal bones are among the most commonly injured facial bones and are significant in both trauma and reconstructive surgery:

• Nasal bone fractures:

  • Most common facial bone fractures, typically resulting from blunt trauma (e.g., falls, sports, assaults).

  • Symptoms include nasal deformity, swelling, bruising, epistaxis (nosebleed), and impaired breathing.

  • May require closed reduction or rhinoplasty depending on severity and displacement.

• Rhinoplasty considerations:

  • Cosmetic procedures often involve reshaping or repositioning nasal bones to alter nose profile and symmetry.

• Congenital anomalies:

  • Hypoplastic nasal bones are associated with certain syndromes (e.g., Down syndrome) and can be detected via prenatal ultrasound.

• Nasal obstruction:

  • Displaced or malformed nasal bones can contribute to chronic nasal blockage and may require surgical correction.