Nasal Bones

What Does the Nasal Ridge Do

The nasal ridge consists of a pair of bones in the human skull. These petite, level bones are a component of the facial framework, composing the upper section of the nose. 

Where Can It Be Found

The two nasal bones are positioned adjacently between the frontal processes of the left and right maxillae. They are detectable in the upper central part of the face, at the bridge of the nose.

Key Points

Roles

The primary function is to shape the front wall of the nasal cavity and safeguard it from external factors and unforeseen injuries. 

They unite to form the structure of the nose, giving these two bones the primary responsibility for the nose’s form.

Their dimensions and shape frequently differ from person to person, giving rise to the distinctive shapes and sizes of noses across individuals.

Structure

Each bone possesses 2 surfaces and 4 boundaries. 

Surfaces

1. Outer surface: This is the curved external surface covered by the facial muscles procerus and compressor naris. A small foramen at the center of each nasal bone allows passage to a small vein.
2. Inner surface: The concave internal surface marked with a groove allows the anterior ethmoidal nerve to pass. It is a branch of the nasociliary nerve, a sensory nerve in the eye (part of the ophthalmic nerve)

Boundaries and Connections

1. Upper boundary: This narrow and serrated boundary connects with the frontal bone’s nasal part at the frontonasal suture.
2. Side boundary: Another beveled, serrated boundary, it forms the nasomaxillary suture where it connects with the frontal process of the maxilla.
3. Lower boundary: The thin lower boundary is joined to the lateral nasal cartilage with the sole important landmark being a small notch where the groove for the anterior ethmoidal nerve ends.
4. Medial boundary: Here, the two nasal bones connect with each other at the internasal suture. A projection or crest on the posterior side of the boundary on each bone partially forms the nasal septum. The crest attaches to the frontal bone’s nasal spine, the ethmoid’s perpendicular plate, and the septal cartilage

References

1. Nasal bone: KenHub.com
2. Nasal bone: HealthLine.com
3. Nasal bone: Anatomy.app 
4. Nasal bone: IMAIOS.com
5. Nasal bone: RadioPaedia.org