Petrosquamous suture

Petrosquamous suture
Temporal bone at birth. Inner aspect.
Base of the skull. Upper surface. (Temporal bone is in pink.)
Details
Identifiers
Latin	sutura petrosquamosa
TA98	A02.1.06.075
TA2	718
FMA	55466
Anatomical terms of bone [edit on Wikidata]

The petrosquamous suture is a cranial suture between the petrous portion and the squama of the temporal bone. It forms the Koerner's septum. The petrous portion forms the medial component of the osseous margin, while the squama forms the lateral component. The anterolateral portion (squama) arises from the mesenchyme at 8 weeks of embryogenesis while the petromastoid portion develops later from a cartilaginous center at 6 months of fetal development.^[1]

In certain people, it can contain an emissary vein, referred to as the petrosquamosal sinus. Being aware of this anatomic variant with preoperative CT scanning can be important to prevent bleeding in certain types of otolaryngological surgeries. Some authors have theorized that a persistent venous sinus reflects an arrest in embryologic development.^[1]

References

^ ^a ^b "The Petrosquamosal Sinus: CT and MR Findings of a Rare Emissary Vein". American Journal of Neuroradiology. 2001. pp. 1186–1193.

This article incorporates text in the public domain from page 142 of the 20th edition of Gray's Anatomy (1918)

External links

Diagram

Neurocranium of the skull

Occipital

Squamous part	external Inion/External occipital protuberance Occipital bun External occipital crest Nuchal lines Suprainiac fossa planes Occipital Nuchal internal Cruciform eminence Internal occipital protuberance Internal occipital crest Groove for transverse sinus
Lateral parts	Condyle Condyloid fossa Condylar canal Hypoglossal canal jugular Jugular process Jugular tubercle
Basilar part	Pharyngeal tubercle Clivus
Other	Foramen magnum Basion Opisthion

Parietal

Frontal

Squamous part	Frontal suture Frontal eminence external Superciliary arches Glabella foramina Supraorbital foramen Brow ridge Foramen cecum Zygomatic process internal Sagittal sulcus Frontal crest
Orbital part	Ethmoidal notch Fossa for lacrimal gland Trochlear fovea Frontal sinus Frontonasal duct

Temporal

Squamous part	Articular tubercle Suprameatal triangle Mandibular fossa Petrotympanic fissure Zygomatic process
Mastoid part	Mastoid foramen Mastoid process (Mastoid cells) Mastoid notch Occipital groove Sigmoid sulcus Mastoid antrum (Aditus)
Petrous part	Carotid canal Facial canal Hiatus Internal auditory meatus Cochlear aqueduct Stylomastoid foramen fossae Subarcuate fossa Jugular fossa canaliculi Inferior tympanic Mastoid Styloid process Petrosquamous suture (note: ossicles in petrous part, but not part of temporal bone)
Tympanic part	Suprameatal spine

Sphenoid

Surfaces	Superior surface: Sella turcica Dorsum sellae Tuberculum sellae Hypophysial fossa Posterior clinoid processes Ethmoidal spine Chiasmatic groove Middle clinoid process Petrosal process Clivus Lateral surface: Carotid groove Sphenoidal lingula Anterior surface: Sphenoidal sinuses
Great wings	foramina Rotundum Ovale Vesalii Spinosum Spine Infratemporal crest Sulcus of auditory tube
Small wings	Superior orbital fissure Anterior clinoid process Optic canal
Pterygoid processes	fossae Pterygoid Scaphoid pterygoid plates Lateral Medial Pterygoid canal Hamulus
Other	Body Sphenoidal conchae

Ethmoid

Plates	Cribriform plate Crista galli Olfactory foramina Perpendicular plate
Surfaces	Lateral surface Orbital lamina Uncinate process Medial surface Supreme nasal concha Superior nasal concha Superior meatus Middle nasal concha Middle meatus
Labyrinth	Ethmoid sinus ethmoidal foramina Posterior Anterior

v t e Fibrous joints of the human skull
Syndesmosis	Pterygospinous ligament Stylohyoid ligament
Sutures	Involving the frontal bone frontoethmoidal suture frontal suture coronal suture occipitomastoid lambdoid sagittal Involving the sphenoid bone sphenoethmoidal with frontal bone with parietal bone sphenosquamosal Involving the Petrous part of the temporal bone sphenopetrosal petrosquamous squamosal Facial: palatomaxillary suture Involving the zygomatic process with sphenoid bone with temporal bone with frontal bone
Mouth	Gomphosis Periodontal fiber Periodontium Dental alveolus Gingiva Cementum