Vomer

At a glance

English

Vomer

Latin (TA2)

Vomer

System

Bone

Region

Head

Side

Single, on the midline

About the vomer

The vomer is a single, flat, roughly four-sided bone set upright in the midline of the nasal cavity. Its name, from the Latin for a ploughshare, describes its outline. It forms the lower and back part of the bony nasal septum, while the ethmoid's perpendicular plate forms the upper front part and the septal cartilage fills in the front. Although it lies in the median plane, its front part is often bent to one side, one of the reasons the nasal septum is so commonly deviated.

Its two side faces are thin and covered with mucous membrane, and they bear fine vascular grooves. Running down and forwards across each face is a longer groove for the nasopalatine nerve and vessels, which travel from the roof of the nose to the front of the palate.

The four borders each have a different partner. The upper border is the thickest: it splits into two wings, the alae, that clasp the rostrum on the underside of the sphenoid body and meet the sphenoid's vaginal processes and the palatine bones' sphenoidal processes. The lower border sits in the nasal crest made by the two maxillae and palatine bones along the floor of the nose. The long front border slopes forwards and down; its upper half is fused to the ethmoid's perpendicular plate while a groove along its lower half takes the septal cartilage. The back border is free, with nothing attached: it is concave, thick and forked above, thin below, and divides the two posterior nasal openings, the choanae.

The vomer therefore meets the sphenoid, ethmoid, both maxillae, both palatine bones and the septal cartilage. Its free back edge is the midline landmark when the choanae are viewed through an endoscope or on imaging, and surgeons trim it or the cartilage in front of it to straighten a deviated septum.

Function and supply

Function

Divides the back of the nasal cavity into right and left passages and supports the septal cartilage in front.

Nerve supply

Not innervated as a muscle is; the nasopalatine nerve, from the maxillary nerve through the pterygopalatine ganglion, runs down its surfaces in the vomerine groove and supplies the septal mucosa.

Blood supply

Septal branches of the sphenopalatine artery run with the nasopalatine nerve over its surfaces, and posterior ethmoidal branches reach its upper part.