The vomer is a single bone located vertically at the back of nasal cavity forming part of the nasal septum. Its superior border is split into two ala or wings of vomer (alae vomeris), which fit over the rostrum of the sphenoid bone. The vomer articulates with the:
- Perpendicular plate of the ethmoid bone.
- Cartilaginous nasal septum.
- Nasal crests of the maxilla.
- Nasal crests of the palatine bone.
The posterior border of the bony nasal septum is formed by the posterior edge of the vomer. At the posterior border of the vomer is located the vomerine crest of choana (crista choanalis vomeris). This crest separates the posterior openings of the nasal cavity which area called choanae (choanae). They communicate the nasal cavity with the nasopharynx. On the left and right sides of the vomer are also present the vomerine grooves (sulcus nasopalatinus).
The commonest deviation of the septum is caused by dislocation of the septal cartilage from the vomer. Nasal deviation usually occurs as a birth trauma. During natural childbirth the head of fetus rotates and the nose is pushed to the pelvic surface of the sacrum. Damage to the vomer during the dislocation leads to thickening of the bone called a spur. Deviation of the septal cartilage produces a widening of one nasal air passage.