Mastoid foramen

{{Short description|Hole in the back of the temporal bone}}

{{Infobox bone

| Name = Mastoid foramen

| Latin = foramen mastoideum

| Image = File:Gray138.png

| Caption = Left temporal bone. Inner surface. (Mastoid foramen labeled at bottom left.)

| Image2 = File:Gray193.png

| Caption2 = Base of the skull. Upper surface. (Temporal bone is pink, and label for mastoid foramen is at left, second from the bottom.)

|PartOf=Temporal bone of skull|System=Skeletal}}

The mastoid foramen is a hole in the posterior border of the temporal bone. It transmits an emissary vein between the sigmoid sinus and the suboccipital venous plexus, and a small branch of the occipital artery, the posterior meningeal artery to the dura mater.

Structure

The mastoid foramen is a hole in the posterior border of the temporal bone of the skull.{{Cite journal|last1=Wang|first1=Cindy|last2=Lockwood|first2=Joseph|last3=Iwanaga|first3=Joe|last4=Dumont|first4=Aaron S.|last5=Bui|first5=C. J.|last6=Tubbs|first6=R. Shane|date=June 2021|title=Comprehensive review of the mastoid foramen|url=https://link.springer.com/10.1007/s10143-020-01329-9|journal=Neurosurgical Review|language=en|volume=44|issue=3|pages=1255–1258|doi=10.1007/s10143-020-01329-9|pmid=32507931 |s2cid=219529416 |issn=0344-5607}}

The opening of the mastoid foramen is an average of 18 mm from the asterion,{{Cite journal|last1=Hampl|first1=Martin|last2=Kachlik|first2=David|last3=Kikalova|first3=Katerina|last4=Riemer|first4=Roxane|last5=Halaj|first5=Matej|last6=Novak|first6=Vlastimil|last7=Stejskal|first7=Premysl|last8=Vaverka|first8=Miroslav|last9=Hrabalek|first9=Lumir|last10=Krahulik|first10=David|last11=Nanka|first11=Ondrej|date=2018-07-01|title=Mastoid foramen, mastoid emissary vein and clinical implications in neurosurgery|journal=Acta Neurochirurgica|language=en|volume=160|issue=7|pages=1473–1482|doi=10.1007/s00701-018-3564-2|pmid=29779186 |s2cid=29158669 |issn=0942-0940|doi-access=free}} and around 34 mm from the external auditory meatus.{{Cite journal|last1=Kim|first1=Won Sik|last2=Kim|first2=Soo Il|last3=Kim|first3=Sun|last4=Zheng|first4=Guo Dong|last5=Yang|first5=Eun Jin|last6=Han|first6=Seung Ro|date=2000-03-31|title=Mastoid Foramen and Superficial Mastoid Canals of Korean Men|url=https://synapse.koreamed.org/articles/1038727|journal=Korean Journal of Physical Anthropology|volume=13|issue=1|pages=11–19|doi=10.11637/kjpa.2000.13.1.11}} It is typically very narrow. This may be around 2 mm.

=Variation=

The position and size of this foramen are very variable. It is not always present. Sometimes, it is duplicated on one side or both sides. Sometimes, it is situated in the occipital bone, or in the suture between the temporal bone and the occipital bone.

Function

The mastoid foramen transmits:

References

{{Gray's}}