Stylomastoid foramen

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Stylomastoid foramen
Stylomastoid foramen.png
Base of skull. Inferior surface. Pink region is temporal bone, and stylomastoid foramen is in black circle at center of pink region.
Gray141.png
Left temporal bone. Inferior surface. (Stylomastoid foramen is third label from the bottom on the left.)
Details
Part of Temporal bone of skull
System Skeletal
Identifiers
Latin foramen stylomastoideum
TA98 A02.1.06.048
TA2 684
FMA 55816
Anatomical terms of bone

The stylomastoid foramen is a foramen between the styloid and mastoid processes of the temporal bone of the skull. It is the termination of the facial canal, and transmits the facial nerve, and stylomastoid artery. Facial nerve inflammation in the stylomastoid foramen may cause Bell's palsy.

Contents

Structure

The stylomastoid foramen is between the styloid and mastoid processes of the temporal bone. The average distance between the opening of the stylomastoid foramen and the styloid process is around 0.7 mm or 0.8 mm in adults, but may decrease to around 0.2 mm during aging. [1]

The stylomastoid foramen transmits the facial nerve, [2] [3] and the stylomastoid artery. [3] These 2 structures lie directly next to each other. [3]

Clinical significance

Bell's palsy can result from inflammation of the facial nerve where it leaves the skull at the stylomastoid foramen. Patients with Bell's palsy appear with facial drooping on the affected side.

Additional images

Related Research Articles

<span class="mw-page-title-main">Facial nerve</span> Cranial nerve VII, for the face and tasting

The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue. The nerve typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen. It arises from the brainstem from an area posterior to the cranial nerve VI and anterior to cranial nerve VIII.

<span class="mw-page-title-main">Foramen ovale (skull)</span> Hole in the sphenoid bone of the skull

The foramen ovale is a hole in the posterior part of the sphenoid bone, posterolateral to the foramen rotundum. It is one of the larger of the several holes in the skull. It transmits the mandibular nerve, a branch of the trigeminal nerve.

<span class="mw-page-title-main">Temporal bone</span> Bone of the neurocranium

The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex.

<span class="mw-page-title-main">Digastric muscle</span> Small muscle located under the jaw in mammals

The digastric muscle is a bilaterally paired suprahyoid muscle located under the jaw. Its posterior belly is attached to the mastoid notch of temporal bone, and its anterior belly is attached to the digastric fossa of mandible; the two bellies are united by an intermediate tendon which is held in a loop that attaches to the hyoid bone. The anterior belly is innervated via the mandibular nerve, and the posterior belly is innervated via the facial nerve. It may act to depress the mandible or elevate the hyoid bone.

<span class="mw-page-title-main">Middle meningeal artery</span> Artery supplying the meninges

The middle meningeal artery is typically the third branch of the first portion of the maxillary artery. After branching off the maxillary artery in the infratemporal fossa, it runs through the foramen spinosum to supply the dura mater and the calvaria. The middle meningeal artery is the largest of the three (paired) arteries that supply the meninges, the others being the anterior meningeal artery and the posterior meningeal artery.

<span class="mw-page-title-main">Foramen lacerum</span> Triangular hole in the base of the skull

The foramen lacerum is a triangular hole in the base of skull. It is located between the sphenoid bone, the apex of the petrous part of the temporal bone, and the basilar part of the occipital bone.

<span class="mw-page-title-main">Posterior cranial fossa</span> Area of the cranium containing the brainstem and cerebellum

The posterior cranial fossa is the part of the cranial cavity located between the foramen magnum, and tentorium cerebelli. It is formed by the sphenoid bones, temporal bones, and occipital bone. It lodges the cerebellum, and parts of the brainstem.

<span class="mw-page-title-main">Hypoglossal canal</span> Hole in the occipital bone of the skull

The hypoglossal canal is a foramen in the occipital bone of the skull. It is hidden medially and superiorly to each occipital condyle. It transmits the hypoglossal nerve.

<span class="mw-page-title-main">Jugular foramen</span> Opening in the base of the skull allowing many structures to pass

A jugular foramen is one of the two large foramina (openings) in the base of the skull, located behind the carotid canal. It is formed by the temporal bone and the occipital bone. It allows many structures to pass, including the inferior petrosal sinus, three cranial nerves, the sigmoid sinus, and meningeal arteries.

<span class="mw-page-title-main">Internal auditory meatus</span> Canal within the temporal bone

The internal auditory meatus is a canal within the petrous part of the temporal bone of the skull between the posterior cranial fossa and the inner ear.

<span class="mw-page-title-main">Posterior auricular artery</span> Small artery

The posterior auricular artery is a small artery that arises from the external carotid artery. It ascends along the side of the head. It supplies several muscles of the neck and several structures of the head.

<span class="mw-page-title-main">Infraorbital foramen</span> Opening in the maxillary bone of the skull

In human anatomy, the infraorbital foramen is one of two small holes in the skull's upper jawbone, located below the eye socket and to the left and right of the nose. Both holes are used for blood vessels and nerves. In anatomical terms, it is located below the infraorbital margin of the orbit. It transmits the infraorbital artery and vein, and the infraorbital nerve, a branch of the maxillary nerve. It is typically 6.10 to 10.9 mm from the infraorbital margin.

<span class="mw-page-title-main">Mastoid part of the temporal bone</span> Back part of the sides of the skull base

The mastoid part of the temporal bone is the posterior (back) part of the temporal bone, one of the bones of the skull. Its rough surface gives attachment to various muscles and it has openings for blood vessels. From its borders, the mastoid part articulates with two other bones.

<span class="mw-page-title-main">Petrous part of the temporal bone</span> Feature at the base of the human skull

The petrous part of the temporal bone is pyramid-shaped and is wedged in at the base of the skull between the sphenoid and occipital bones. Directed medially, forward, and a little upward, it presents a base, an apex, three surfaces, and three angles, and houses in its interior, the components of the inner ear. The petrous portion is among the most basal elements of the skull and forms part of the endocranium. Petrous comes from the Latin word petrosus, meaning "stone-like, hard". It is one of the densest bones in the body. In other mammals, it is a separate bone, the petrosal bone.

<span class="mw-page-title-main">Tympanic part of the temporal bone</span> Middle part of the sides of the skull base, surrounding the ear canal

The tympanic part of the temporal bone is a curved plate of bone lying below the squamous part of the temporal bone, in front of the mastoid process, and surrounding the external part of the ear canal.

<span class="mw-page-title-main">Temporal styloid process</span> Part of the temporal bone

The temporal styloid process is a slender bony process of the temporal bone extending downward and forward from the undersurface of the temporal bone just below the ear. The styloid process gives attachments to several muscles, and ligaments.

<span class="mw-page-title-main">Facial canal</span> Hole in the temporal bone of the skull carrying the facial nerve

The facial canal is a Z-shaped canal in the temporal bone of the skull. It extends between the internal acoustic meatus and stylomastoid foramen. It transmits the facial nerve.

<span class="mw-page-title-main">Middle cranial fossa</span>

The middle cranial fossa is formed by the sphenoid bones, and the temporal bones. It lodges the temporal lobes, and the pituitary gland. It is deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull. It is separated from the posterior cranial fossa by the clivus and the petrous crest.

<span class="mw-page-title-main">Mastoid foramen</span> Hole in the back of the temporal bone

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.

<span class="mw-page-title-main">Pterygoid canal</span>

The pterygoid canal is a passage in the sphenoid bone of the skull leading from just anterior to the foramen lacerum in the middle cranial fossa to the pterygopalatine fossa.

References

PD-icon.svgThis article incorporates text in the public domain from page 144 of the 20th edition of Gray's Anatomy (1918)

  1. Krmpotić Nemanić, Jelena; Vinter, Ivan; Ehrenfreund, Tin; Marušić, Ana (2008-12-17). "Postnatal changes in the styloid process, vagina processus styloidei, and stylomastoid foramen in relation to the function of muscles originating from the styloid process". Surgical and Radiologic Anatomy . 31 (5): 343. doi:10.1007/s00276-008-0450-2. ISSN   1279-8517.
  2. Curtin, H D; Wolfe, P; Snyderman, N (October 1983). "The facial nerve between the stylomastoid foramen and the parotid: computed tomographic imaging". Radiology . 149 (1): 165–169. doi:10.1148/radiology.149.1.6611924. ISSN   0033-8419.
  3. 1 2 3 Bourdon, Nicolas; Babin, Emmanuel; Moreau, Sylvain; Salame, Ephrem; Valdazo, André; De Rugy, Marc Goullet; Delmas, Pierre (2000-09-01). "Facial Nerve: Vascular-Related Anatomy at the Stylomastoid Foramen". Annals of Otology, Rhinology & Laryngology. 109 (9): 849–852. doi:10.1177/000348940010900912. ISSN   0003-4894.