Foramen ovale (skull)

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Foramen ovale of sphenoid bone
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Sphenoid bone. Upper surface. (foramen ovale labeled at left, third from bottom)
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Horizontal section of nasal and orbital cavities.
Details
Part of Sphenoid bone
System Skeletal
Identifiers
Latin foramen ovale ossis sphenoidalis
TA98 A02.1.05.036
TA2 622
FMA 53155
Anatomical terms of bone

The foramen ovale (Latin: oval window) 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 (the foramina) in the skull. It transmits the mandibular nerve, a branch of the trigeminal nerve.

Contents

Structure

Foramen ovale Base of skull 12.jpg
Foramen ovale

The foramen ovale is an opening in the greater wing of the sphenoid bone. [1] The foramen ovale is one of two cranial foramina in the greater wing, the other being the foramen spinosum. [2] :771 The foramen ovale is posterolateral to the foramen rotundum and anteromedial to the foramen spinosum. Posterior and medial to the foramen is the opening for the carotid canal. [2] :776

Contents

The following structures pass through foramen ovale:

Variation

In a study conducted on 100 skulls, the foramen ovale was divided into 2 or 3 components in 4.5% of the cases. The borders of the foramen in some skulls were also irregular and rough. This may suggest, based on radiological images, the presence of morbid changes, which might be the sole anatomical variation in the foramina ovalia of humans. [4]

In newborn, the foramen ovale is about 3.85 mm and in the adults about 7.2 mm in length. The average maximal length is about 7.48 mm and its average minimal length is 4.17 mm in the adult. The width extends from 1.81 mm in the newborn to 3.7 mm in adults. [5] [6]

Development

Similar to other foramina, the foramen ovale differs in shape and size throughout life. In a study using over 350 skulls, the earliest perfect ring-shaped formation of the foramen ovale was observed in the 7th month of fetal life, and the latest in 3 years after birth. [5]

Clinical significance

The foramen ovale is used as the entry point into the skull when conducting a Percutaneous Rhizotomy using either radio-frequency ablation, balloon compression or glycerol injection. These are performed to treat trigeminal neuralgia. In the procedure, the electrode is introduced through the cheek of an anesthetized patient and radiologically guided into the foramen ovale, with the intention of partially or fully ablating one or more of the divisions (typically the Mandibular) to relieve pain. [7]

This entry point is also used to surgically place local electrodes directly on the surface of the mesial temporal lobe, in order to observe neural activity of patients with suspected focal epilepsy. [8]

History

Etymology

The name "foramen ovale" comes from the Latin "oval hole / window".

See also

Related Research Articles

<span class="mw-page-title-main">Mandibular nerve</span> Branch of the trigeminal nerve responsible for the lower face and jaw

In neuroanatomy, the mandibular nerve (V3) is the largest of the three divisions of the trigeminal nerve, the fifth cranial nerve (CN V). Unlike the other divisions of the trigeminal nerve (ophthalmic nerve, maxillary nerve) which contain only afferent fibers, the mandibular nerve contains both afferent and efferent fibers. These nerve fibers innervate structures of the lower jaw and face, such as the tongue, lower lip, and chin. The mandibular nerve also innervates the muscles of mastication.

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

The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended.

<span class="mw-page-title-main">Orbit (anatomy)</span> Cavity or socket of the skull in which the eye and its appendages are situated

In anatomy, the orbit is the cavity or socket/hole of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is 30 millilitres, of which the eye occupies 6.5 ml. The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and duct, the eyelids, medial and lateral palpebral ligaments, cheek ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves.

<span class="mw-page-title-main">Dura mater</span> Outermost layer of the protective tissues around the central nervous system (meninges)

In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. The other two meningeal layers are the arachnoid mater and the pia mater. It envelops the arachnoid mater, which is responsible for keeping in the cerebrospinal fluid. It is derived primarily from the neural crest cell population, with postnatal contributions of the paraxial mesoderm.

<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">Superior orbital fissure</span> Foramen in the skull allowing for passage of cranial nerves

The superior orbital fissure is a foramen or cleft of the skull between the lesser and greater wings of the sphenoid bone. It gives passage to multiple structures, including the oculomotor nerve, trochlear nerve, ophthalmic nerve, abducens nerve, ophthalmic veins, and sympathetic fibres from the cavernous plexus.

<span class="mw-page-title-main">Cavernous sinus</span> Sinus in the human head

The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.

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

The foramen spinosum is a small open hole in the greater wing of the sphenoid bone that gives passage to the middle meningeal artery and vein, and the meningeal branch of the mandibular nerve.

<span class="mw-page-title-main">Maxillary nerve</span> Branch of the trigeminal nerve responsible for the mid-face

In neuroanatomy, the maxillary nerve (V2) is one of the three branches or divisions of the trigeminal nerve, the fifth (CN V) cranial nerve. It comprises the principal functions of sensation from the maxilla, nasal cavity, sinuses, the palate and subsequently that of the mid-face, and is intermediate, both in position and size, between the ophthalmic nerve and the mandibular nerve.

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

The foramen rotundum is a circular hole in the sphenoid bone of the skull. It connects the middle cranial fossa and the pterygopalatine fossa. It allows for the passage of the maxillary nerve (V2), a branch of the trigeminal nerve.

<span class="mw-page-title-main">Pterygopalatine fossa</span> Fossa in the skull

In human anatomy, the pterygopalatine fossa is a fossa in the skull. A human skull contains two pterygopalatine fossae—one on the left side, and another on the right side. Each fossa is a cone-shaped paired depression deep to the infratemporal fossa and posterior to the maxilla on each side of the skull, located between the pterygoid process and the maxillary tuberosity close to the apex of the orbit. It is the indented area medial to the pterygomaxillary fissure leading into the sphenopalatine foramen. It communicates with the nasal and oral cavities, infratemporal fossa, orbit, pharynx, and middle cranial fossa through eight foramina.

<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">Greater wing of sphenoid bone</span> Large part of the skull front behind the eye socket

The greater wing of the sphenoid bone, or alisphenoid, is a bony process of the sphenoid bone, positioned in the skull behind each eye. There is one on each side, extending from the side of the body of the sphenoid and curving upward, laterally, and backward.

<span class="mw-page-title-main">Meningeal branch of the mandibular nerve</span>

The meningeal branch of the mandibular nerve is a sensory branch of the mandibular nerve that enters the middle cranial fossa through either the foramen spinosum or foramen ovale to innervate the meninges of this fossa as well as the mastoid air cells.

<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">Sphenoidal emissary foramen</span>

In the base of the skull, in the great wings of the sphenoid bone, medial to the foramen ovale, a small aperture, the sphenoidal emissary foramen, may occasionally be seen opposite the root of the pterygoid process. When present, it opens below near the scaphoid fossa. Vesalius was the first to describe and illustrate this foramen, and is also called the foramen Vesalius. Other names include foramen venosum and canaliculus sphenoidalis.

<span class="mw-page-title-main">Infratemporal fossa</span> Cavity that is part of the skull

The infratemporal fossa is an irregularly shaped cavity that is a part of the skull. It is situated below and medial to the zygomatic arch. It is not fully enclosed by bone in all directions. It contains superficial muscles, including the lower part of the temporalis muscle, the lateral pterygoid muscle, and the medial pterygoid muscle. It also contains important blood vessels such as the middle meningeal artery, the pterygoid plexus, and the retromandibular vein, and nerves such as the mandibular nerve (CN V3) and its branches.

<span class="mw-page-title-main">Middle meningeal nerve</span>

The middle meningeal nerve (meningeal or dural branch) is given off from the maxillary nerve (CN V2) directly after its origin from the trigeminal ganglion, before CN V2 enters the foramen rotundum.

<span class="mw-page-title-main">Base of skull</span> Inferior area of the skull, composed of the endocranium and lower parts of the skull roof

The base of skull, also known as the cranial base or the cranial floor, is the most inferior area of the skull. It is composed of the endocranium and the lower parts of the calvaria.

References

PD-icon.svgThis article incorporates text in the public domain from page 150 of the 20th edition of Gray's Anatomy (1918)

  1. 1 2 3 4 5 Ray, Biswabina; Gupta, Nirupma; Ghose, Supriya (2005). "Anatomic variations of foramen ovale" (PDF). Kathmandu University Medical Journal. 3 (9): 64–68.
  2. 1 2 3 Drake, Richard L.; Vogl, Wayne; Tibbitts, Adam W.M. Mitchell; illustrations by Richard; Richardson, Paul (2005). Gray's anatomy for students. Philadelphia: Elsevier/Churchill Livingstone. ISBN   978-0-8089-2306-0.
  3. Sinnatamby, Chummy S. (2011). Last's Anatomy (12th ed.). ISBN   978-0-7295-3752-0.
  4. Reymond J, Charuta A, Wysocki J (2005). "The morphology and morphometry of the foramina of the greater wing of the human sphenoid bone". Folia Morphologica. 64 (3): 188–93. PMID   16228954.
  5. 1 2 Yanagi S (1987). "Developmental studies on the foramen rotundum, foramen ovale and foramen spinosum of the human sphenoid bone". The Hokkaido Journal of Medical Science. 62 (3): 485–96. PMID   3610040.
  6. Lang J, Maier R, Schafhauser O (1984). "Postnatal enlargement of the foramina rotundum, ovale et spinosum and their topographical changes". Anatomischer Anzeiger. 156 (5): 351–87. PMID   6486466.
  7. Tew, John. "Percutaneous stereotactic rhizotomy (PSR) for facial pain". Mayfield Brain & Spine. Retrieved 5 December 2016.
  8. Velasco, TR; Sakamoto, AC; Alexandre, V Jr; Walz, R; Dalmagro, CL; Bianchin, MM; Araújo, D; Santos, AC; Leite, JP; Assirati, JA; Carlotti, C Jr (2006). "Foramen ovale electrodes can identify a focal seizure onset when surface EEG fails in mesial temporal lobe epilepsy". Epilepsia. 47 (8): 1300–7. doi:10.1111/j.1528-1167.2006.00547.x. PMID   16922874.