Vomer Bone

1. Overview

The vomer bone is a thin, flat, and plow-shaped facial bone that forms the inferior portion of the nasal septum. It plays a critical role in dividing the nasal cavity into right and left halves. Although small and often overlooked, the vomer contributes to both the structural integrity and function of the nasal passages.

2. Location

The vomer is located in the midline of the nasal cavity:

• Superiorly: Articulates with the perpendicular plate of the ethmoid bone, forming the upper nasal septum.

• Inferiorly: Rests on the nasal crest formed by the maxilla and palatine bones.

• Anteriorly: Contacts the cartilaginous part of the nasal septum.

• Posteriorly: Forms the posterior free edge of the nasal septum, separating the choanae (posterior nasal apertures).

3. Structure

The vomer is a singular, unpaired bone characterized by:

• Shape: Thin and trapezoidal when viewed from the front; resembles a plowshare (hence its name).

• Surfaces: Two lateral surfaces, which are smooth and slightly concave, facing the nasal cavities.

• Borders: Four borders — superior (articulates with sphenoid and ethmoid), inferior (rests on hard palate), anterior (connects to septal cartilage), and posterior (forms the posterior nasal septum).

• Articulations: The vomer articulates with six bones — the sphenoid, ethmoid, two palatine bones, and two maxillae — as well as the septal cartilage.

4. Function

The vomer bone has specific structural functions:

• Forms part of the nasal septum: Helps divide the nasal cavity into left and right chambers.

• Supports cartilage: Provides a bony foundation for the nasal septal cartilage, aiding in the stability of the external nose.

• Maintains airflow symmetry: Assists in directing nasal airflow evenly between both nasal passages.

5. Physiological role(s)

Although passive in function, the vomer contributes to key physiological processes:

• Airflow regulation: By contributing to septal structure, it ensures balanced and efficient air passage through the nose.

• Support for mucosa: Acts as a scaffold for nasal mucosa lining involved in humidifying and filtering air.

• Olfactory assistance: Helps maintain proper airflow patterns for optimal olfaction (sense of smell).

6. Clinical Significance

Disorders involving the vomer can impact nasal function and may require clinical attention:

• Deviated nasal septum:

  • Displacement or abnormal angulation of the vomer contributes to septal deviation, which may cause nasal obstruction, snoring, or sinus infections.

• Septoplasty:

  • A surgical procedure where parts of the vomer may be reshaped or partially removed to correct a deviated septum.

• Craniofacial anomalies:

  • Congenital conditions like cleft palate or midface hypoplasia may involve vomer abnormalities, affecting nasal structure and function.

• Trauma:

  • Although rare, direct trauma to the nasal septum can fracture the vomer, leading to septal hematomas or nasal deformity.

• Imaging relevance:

  • The vomer is commonly visualized in CT scans of the paranasal sinuses and is a key landmark in endoscopic sinus and skull base surgeries.