Sphenoid sinus

The sphenoid sinus is the most posterior paranasal sinus.


Gross anatomy

The sphenoid sinuses are paired spaces formed within the body of the sphenoid bone, communicating with the roof of the nasal cavity via the sphenoethmoidal recess in its anterior wall. The two sinuses are separated by a septum which may or may not be in the midline. It usually lies anteroinferior to the sella.

A large sinus can show a number of ridges and depressions related to closely adjacent structures. These can include the pituitary gland, optic nerve, and internal carotid artery.

Types of pneumatization
  • conchal
  • lateral recess
  • presellar
  • sellar (which can be incomplete or complete)

Arterial supply

Venous drainage

Lymphatic drainage

Lymph drainage occurs via afferent vessels leading into the retropharyngeal nodes


Variant anatomy

With respect to optic nerve relationship:

  • type 1: adjacent to sphenoid sinus
  • type 2: indenting the sinus
  • type 3: traversing the sinus
  • type 4: adjacent to posterior ethmoid sinus


Pneumatization starts at around 2 years of age and it develops more slowly than the other paranasal sinuses.

Practical points

It is important to look for and report the type of pneumatization of this sinus and to report the relationship with adjacent neurovascular structures, especially dehiscence.

See also

Siehe auch:
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