Sphenoid bone

The sphenoid bone is situated in the center of the skull base and has direct contact with almost all other skull bones (except for nasal, lacrimal bone and mandible). It acts like the cornerstone transmitting and distributing the stress forces applied to the skull^*.

^* Holberg C, Rudzki-Janson I. Stresses at the cranial base induced by rapid maxillary expansion. The Angle Orthodontist, 2006;76(4):543-50.

Download JPG image — Sphenoid bone ex situ & in situ.
To better depict the position of this bone, the picture above shows the skull with the right zygomatic bone removed.

Front view of sphenoid bone with the terminology markup — Ventral aspect of sphenoid bone.
The sphenoid bone comprises the central part – corpus, the pairs of greater and lesser wings, and pterygoid processes.
The list of terms:
Ala minor – Lesser wing of sphenoid
Ala major – Greater wing of sphenoid
Processus pterygoideus – Pterygoid process of the sphenoid
Corpus – Body of sphenoid bone

Top view of sphenoid bone with the terminology markup — Top view of the sphenoid bone, demonstrating the – sella turcica – the saddle-shaped depression on top of the corpus ossis sphenoidalis surrounding the pituitary gland.
The list of terms:
Facies cerebralis alae minoris – Cerebral surface of lesser wing
Facies cerebralis alae majoris – Cerebral surface of greater wing
Jugum sphenoidale
Sella turcica – Turkish saddle
Dorsum sellae
Tuberculum sellae
Fossa hypophysialis – Hypophysial fossa
Sulcus prechiasmaticus – Prechiasmatic groove
Processus clinoideus anterior – Anterior clinoid process

Back view of sphenoid bone with the terminology markup — The dorsal aspect of the sphenoid demonstrating multiple openings and channels within that bone. Canalis opticus and fissura orbitalis superior connect fossa cranii media with the orbit, but foramen rotundum and canalis pterygoides are the pathways to the fossa pterygopalatina.
The list of terms:
Canalis opticus – Optic canal
Fissura orbitalis superior – Superior orbital fissure
Foramen rotundum – Round opening
Canalis pterygoideus – Pterygoid (vidian) canal
Impressiones digitatae – Digitate impressions
Juga cerebralia – Cerebral ridges of cranium
Processus pterygoideus – Pterygoid process
Lamina lateralis processus pterygoidei – Lateral pterygoid plate
Lamina medialis processus pterygoidei – Medial pterygoid plate
Spina ossis phenoidalis – Angular spine of sphenoid

Oblique frontal view of sphenoid bone with the terminology markup — Oblique frontal view of the sphenoid bone
Note the multiple different faces (facies) on the surface of wings, reflecting the complex topographical position of this bone situated in the very middle of the skull.
The list of terms:
Facies orbitalis alae majoris – Orbital surface of greater wing
Facies temporalis alae majoris – Temporal surface of greater wing
Facies maxillaris – Maxillary surface
Facies infratemporalis – Infratemporal surface
Facies orbitalis alae minoris – Orbital surface of lesser wing
Margo zygomaticus – Zygomatic border
Margo frontalis – Frontal border
Margo parietalis – Parietal border
Margo squamosus – Squamous border
Crista infratemporalis – Infratemporal crest
Concha sphenoidalis – Sphenoidal concha
Apertura sinus sphenoidalis – Aperture of sphenoidal sinus
Sinus sphenoidalis – Sphenoidal sinus
Crista sphenoidalis – Sphenoidal crest
Rostrum sphenoidale – Sphenoidal rostrum

Oblique dorsal view of sphenoid bone with the terminology markup — Dorsal oblique view demonstrating the sulcus caroticus – the groove made by the internal carotid artery passing along the corpus's lateral wall.
The list of terms:
Dorsum sellae
Processus clinoideus posterior – Posterior clinoid process
Processus clinoideus anterior – Anterior clinoid process
Sulcus prechiasmaticus – Prechiasmatic groove
Canalis opticus – Optica canal
Sulcus caroticus – Carotid groove
Lingula sphenoidalis
Sulcus tubae ouditoriae – Groove for the cartilaginous part of the auditory tube
Spina ossis sphenoidalis – Angular spine of sphenoid
Fossa scaphoidea – Scaphoid fossa
Incisura pterygoidea – Pterigoid notch
Hamulus pterygoideus – Pterygoid hamulus

Inferior view of sphenoid bone with the terminology markup — Inferior aspect of sphenoid bone.
The list of terms:
Processus pterygoideus – Pterygoid process
Hamulus pterygoideus – Pterygoid hamulus
Sulcus hamuli pterygoidei – Sulcus of pterygoid hamulus
Processus pterygospinosus – Pterygospinous process
Foramen ovale
Foramen spinosum
Fossa scaphoidea – Scaphoid fossa
Processus vaginalis – Vaginal process
Sulcus vomerovaginalis – Vomerovaginal groove
Sulcus palatovaginalis – Palatovaginal groove

The topography of sphenoid bone. 360° rotation.

First published: May/2019
Last update: 16/Oct/2021