Monday, June 27, 2011

Superior Orbital Fissure

Superior orbital fissure

From Wikipedia, the free encyclopedia

The superior orbital fissure is a foramen in the skull, although strictly it is more of a cleft, lying between the lesser and greater wings of the sphenoid bone.

Bone: Superior orbital fissure



Contents

1 Structures passing through

1 Foramen ethmoidale, 2 Canalis opticus, 3 Fissura orbitalis superior, 4 Fossa sacci lacrimalis, 5 Sulcus infraorbitalis, 6 Fissura orbitalis inferior, 7 Foramen infraorbitale

2 Pathology

2.1 Superior orbital fissure syndrome



3 Additional images

4 See also

5 References

6 External links

Structures passing through

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A number of important anatomical structures pass through the fissure, and these can be damaged in orbital trauma, particularly blowout fractures through the floor of the orbit into the maxillary sinus. These structures are:

Dissection showing origins of right ocular muscles, and nerves entering by the superior orbital fissure.

Latin

fissura orbitalis superior

Gray's

subject #201 900⁠

superior and inferior divisions of oculomotor nerve (III)

trochlear nerve (IV)

lacrimal, frontal and nasociliary branches of ophthalmic nerve (V1)

abducens nerve (VI)

superior and inferior divisions of ophthalmic vein. Inferior division also passes through the inferior orbital fissure.

sympathetic fibers from cavernous plexus

These include nonvisual sensory messages, such as pain, or motor nerves. They also serve as vascular connections. [1]

The nerves passing through the fissure can be remembered with the mnemonic, "Live Frankly To See Absolutely No Insult" - for Lacrimal, Frontal, Trochlear, Superior Division of Oculomotor, Abducens, Nasociliary and Inferior Division of Oculomotor nerve. [2]



It is divided into 3 parts from lateral to medial: Lateral Part transmits: lacrimal nerve, frontal nerve, trochlear nerve, meningeal branch of lacrimal artery, anastomotic branch of middle meningeal artery which anastomoses with recurrent branch of the lacrimal artery Middle Part transmits: Upper and lower divisions of the oculomotor nerve, nasociliary nerve between the two divisions of oculomotor nerve and abducent nerve Medial Part transmits: Superior ophthalmic vein and sympathetic nerves from the plexus around internal carotid artery

Human skull from front and behind with calvarium removed. White area in posterior of orbital cavity is the superior orbital fissure.

Pathology

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The abducens nerve is most likely to show signs of damage first, with the most common complaints retro-orbital pain and the involvement of cranial nerves III, IV, V1, and VI without other neurological signs or symptoms. This presentation indicates either compression of structures in the superior orbital fissure or the cavernous sinus.

Superior orbital fissure syndrome

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Superior orbital fissure syndrome, also known as Rochon-Duvigneaud's syndrome, [3][4] is a neurological disorder that results if the superior orbital fissure is fractured. Involvement of the cranial nerves that pass through the superior orbital fissure may lead to diplopia, paralysis of extraocular motions, exophthalmos, and ptosis. Blindness or loss of vision indicates involvement of the orbital apex, which is more serious, requiring urgent surgical intervention. Typically, if blindness is present with superior orbital syndrome, it is called orbital apex syndrome.

Additional images

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Sphenoid bone. Upper surface  

Sphenoid bone. Upper and posterior surfaces  





Photo of skull with major foramina labeled  

The skull from the front  



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Foramina of skull

Inferior orbital fissure

References

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^ "eye, human."Encyclopædia Britannica from Encyclopædia Britannica 2006 Ultimate Reference Suite DVD

^ "Superior orbital fissure: Structures passing through"⁠. LifeH

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