| Foramen ovale of sphenoid bone | |
|---|---|
 Sphenoid bone. Upper surface. (foramen ovale labeled at left, third from bottom) | |
 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 | |
Theforamen ovale (En: oval window) is a hole in the posterior part of thesphenoid bone, posterolateral to theforamen rotundum. It is one of the larger of the several holes (theforamina) in the skull. It transmits themandibular nerve, a branch of thetrigeminal nerve.
Theforamen ovale is an opening in the greater wing of thesphenoid bone.[1] The foramen ovale is one of twocranial foramina in the greater wing, the other being theforamen spinosum.[2]: 771 The foramen ovale is posterolateral to theforamen rotundum and anteromedial to theforamen spinosum. Posterior and medial to the foramen is the opening for thecarotid canal.[2]: 776
The following structures pass through foramen ovale:
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]
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]
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 treattrigeminal 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 themesial temporal lobe, in order to observe neural activity of patients with suspected focal epilepsy.[8]
The name "foramen ovale" comes from theLatin "oval hole / window".
This article incorporates text in thepublic domain frompage 150 of the 20th edition ofGray's Anatomy(1918)
