Skeletal system · Head and neck
Foramen rotundum !
The foramen rotundum is a round opening in the sphenoid bone; it carries the maxillary nerve, which gives feeling to the cheek and upper teeth.
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What it is
A round opening in the sphenoid.
What it does
Carries the maxillary nerve (V2).
Key facts
- Where
- Greater wing of the sphenoid
- Function
- Transmits the maxillary nerve (V2)
Relations
- Contents
- Maxillary nerve (V2), with small emissary veins and a small branch of the maxillary artery
- Course
- Runs forward through the root of the greater wing of the sphenoid bone, from the floor of the middle cranial fossa below the cavernous sinus to the upper back wall of the pterygopalatine fossa
- Above
- Medial end of the superior orbital fissure
- Below
- Pterygoid canal, below and medial, carrying the nerve of the pterygoid canal
- Medial
- Body of the sphenoid with the sphenoid sinus, whose lateral recess may wrap around it
- In front
- Pterygopalatine fossa, with the pterygopalatine ganglion and the end of the maxillary artery
How to find it
It cannot be felt. Inside the skull it opens in the floor of the middle cranial fossa just below the medial end of the superior orbital fissure; from the front it is the upper hole in the back wall of the pterygopalatine fossa, reached endoscopically through the nose or the maxillary sinus.
On imaging
Coronal CT shows it as a round hole above and lateral to the pterygoid canal. Widening or erosion of the canal, or loss of the normal fat in the pterygopalatine fossa, suggests perineural spread; contrast MRI with fat suppression shows the nerve thickened and enhancing.
Clinical notes
- Numbness of the cheek, upper lip and upper teeth that slowly spreads after a treated skin, palate or sinus cancer suggests spread along V2
- The canal is a landmark in endoscopic approaches to the pterygopalatine fossa, the infratemporal fossa and the middle cranial fossa
- V2 can be blocked in the pterygopalatine fossa as it leaves the canal, numbing the whole maxillary territory
Anatomical variants
- A well-aerated sphenoid sinus can extend into the greater wing so that the canal bulges into the sinus; texts differ on how often
Related conditions
Test yourself
Think of the answer, then tap the question to see it.
Which nerve passes through the foramen rotundum, and where does it go?
The maxillary nerve (V2), forward from the middle cranial fossa into the pterygopalatine fossa.
What does slowly spreading numbness of the cheek and upper lip after a treated skin or sinus cancer suggest?
Perineural tumour spread back along V2 through the foramen rotundum toward the cavernous sinus and trigeminal ganglion.
Which canal can be confused with the foramen rotundum on coronal CT?
The pterygoid (Vidian) canal, which lies below and medial to it.
Educational information, not medical advice. For any symptom, see a health professional.
Its names
- Official Latin (TA2)
- foramen rotundum TA2 621
- Official Spanish (DeCS)
- Agujero redondo
- English (TA2)
- Foramen rotundum
- Also called
- canalis rotundus
Related
Sources: Terminologia Anatomica (TA2); Anatomy, Head and Neck, Skull Foramen; Anatomy, Head and Neck, Maxillary Nerve.
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Representative model, for educational purposes only.