Ethmoidal air cells

The ethmoidal air cells (or less commonly, the ethmoidal sinuses) form one of the four pairs of paranasal sinuses. They are located within the single, midline ethmoid bone. They are present at birth and they develop rapidly from 0-4 year-old; they further mature from 8-12 year-old during puberty.

Gross anatomy

A collection of air cells (3-18 in number) divided by bony septa within the lateral mass, or labyrinth, of the ethmoid bone

Separated into anterior and posterior groups by the basal lamella, the lateral attachment of the middle turbinate to the lamina papyracea. Historically the ethmoid sinuses were subdivided into 3 groups of air cells: the anterior, middle and posterior ethmoidal air cells. The so-called middle group are now incorporated into the anterior group.

The anterior ethmoidal air cells drain to the hiatus semilunaris and middle meatus via the ethmoidal bulla, which form parts of the ostiomeatal complex. The posterior ethmoidal air cells drain to the superior meatus and sphenoethmoidal recess 2.

Some of the ethmoidal air cells have their own name, because of their importance in surgical procedures or their involvement in head and neck pathologies:


The posterior ethmoidal air cells, along with the sphenoid sinus, is supplied by the posterior ethmoidal nerve whereas the anterior ethmoidal air cells are supplied by the anterior ethmoidal nerve. Both theses nerves being extraconal branches of the nasociliary nerve, a branch of ophthalmic division of the trigeminal nerve

Head and neck anatomy
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Article information

rID: 25383
System: Head & Neck
Section: Anatomy
Synonyms or Alternate Spellings:
  • Ethmoidal air cell
  • Ethmoidal sinuses
  • Ethmoid sinuses
  • Ethmoid air cells
  • Ethmoid air cell

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