Type:
Educational Exhibit
Keywords:
Infection, Abscess, Education, MR, CT, Head and neck, Ear / Nose / Throat, Bones
Authors:
L. C. Figueroa-Diaz1, M. Betancourt-Torres2, A. Saldana3, J. R. Ortiz-Cruz3, F. G. Rodriguez-Ruiz4, D. E. Labat5, L. E. Garcia-Irizarry1; 1San Juan, PR/US, 2Hato rey, PR/US, 3San Juan, Puerto Rico/US, 4Caguas, Puerto Rico/US, 5San Juan /US
DOI:
10.26044/ecr2019/C-3053
Background
The temporal bone has a complex anatomy and three-dimensional arrangement.
It forms parts of the lateral skull base,
as well as part of the middle and posterior cranial fossa.
The temporal bone can be divided into five parts: squamous,
mastoid,
petrous,
tympanic and styloid process.
Squamous part:
The squamous portion forms the anterior and superior part of the temporal bone and contains the petrotympanic fissure which transmits the chorda tympani branch of the facial nerve.
The inferior part forms a projection called the zygomatic process,
which serves as the origin for the masseter muscle.
Mastoid part:
The mastoid portion forms the posterior part of the bone and contains several foramina including the mastoid foramen which houses the emissary vein and occasionally a branch of the occipital artery.
The mastoid portion of the temporal bone has a conical projection called the mastoid process which not only functions as the origin for the sternocleidomastoid muscle but also includes a section known as the mastoid air cells.
In addition,
a large irregular cavity,
the tympanic antrum is located at the anterior and superior aspect of the bone and is divided from the middle cranial fossa by a thin segment of the temporal bone called the tegmen tympani.
Petrous part:
The petrous portion is located between the sphenoid and occipital bone and contains the hiatus for the facial canal which houses the passage of the greater superficial petrosal nerve and the petrosal branch of the middle meningeal artery.
In the posterior aspect of the petrous portion,
there is a large opening called the internal acoustic meatus.
The internal auditory branch of the basilar artery,
as well as the facial and vestibulocochlear nerves pass through the aforementioned opening.
The inferior surface of the petrous portion contains several important anatomic features including the carotid canal,
jugular fossa,
inferior tympanic canaliculus,
mastoid canaliculus,
styloid process and stylomastoid foramen.
Table 1: Temporal bone foramina and content
Carotid canal |
Internal carotid artery and plexus |
Jugular foramen |
Bulb of the internal jugular vein,
CN IX-XI |
Inferior tympanic canaliculus |
Tympanic branch of glossopharyngeal nerve |
Mastoid canaliculus |
Auricular branch of vagus nerve |
Stylomastoid foramen |
Facial nerve and stylomastoid artery |
Tympanic part:
The tympanic portion of the temporal bone is found anterior to the mastoid process and inferior to the squamous portion.
It forms the anterior wall,
floor and lower posterior wall of the external acoustic meatus.
Styloid part:
The styloid process projects downward and forward from the temporal bone.
It serves as attachment for several muscles and ligaments.
The temporal bone articulates with five bones: occipital,
zygomatic,
mandible,
parietal and sphenoid.