Mastoid air cells

Dr Yuranga Weerakkody and Dr Henry Knipe et al.

The mastoid air cells (cellulae mastoideae) represent the pneumatization of the mastoid part of the temporal bone and are of variable size and extent. 

At the superior and anterior part of the mastoid process the air cells are large and irregular and contain air, but toward the inferior part they diminish in size, while those at the apex of the process are frequently quite small and contain marrow. Occasionally, they are entirely absent.

Mastoid air cells communicate with the middle ear via the mastoid antrum and the aditus ad antrum

The mastoid air cells are traversed by the Koerner septum, a thin bony structure formed by the petrosquamous suture that extends posteriorly from the epitympanum, separating the mastoid air cells into medial and lateral compartments.


Anatomy: Head and neck

Anatomy: Head and neck

Article information

rID: 28366
System: Head & Neck
Section: Anatomy
Tag: sinus
Synonyms or Alternate Spellings:
  • Cellulae mastoidae
  • Mastoid sinus
  • Mastoid sinuses

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Cases and figures

  • Case 1: normal radiographs
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  • Case 2: hyperpneumatisation
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  • Case 3: hypopneumatisation
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