Temporal Fracture

The temporal bone is a huge bone occupying the inferolateral aspect of the skull (See . Temporal Bone Location). Fracturing this bone requires a great deal of force: 1,875 pounds or 850 kg (See . Left Temporal Bone Surface Markings). This amount of trauma can injure the structures associated with the bone and cause significant morbidity and mortality. Temporal bone anatomy is complex (see . Left Temporal Bone, Inner Surface). The bone has 4 regions and numerous foramina and canals. The temporal bones are paired components of the skull base, articulating posteriorly with the occipital bone, superiorly with the parietal bones, anteromedially with the sphenoid bone, and anterolaterally with the zygomatic arches. The temporal bone's squamous portion forms the cranial vault's lateral aspect. The zygomatic process—the posterior part of the zygomatic arch—projects from the squamous part of the temporal bone. The mastoid portion houses the mastoid air cells, while the tympanic portion contains the middle ear cleft and ossicles (See . Temporal Bone Coronal View).  The petrous pyramid is an exceptionally dense segment of the temporal bone (See . Petrous Part Of The Temporal Bone). This structure is widest at the skull's lateral aspect and narrowest as it approaches the sella turcica. The petrous pyramid contains the otic capsule, which houses the inner ear structures (cochlea, vestibule, and semicircular canals) and the internal auditory canal. Additionally, the styloid process projects from the petrous portion of the temporal bone. Besides the auditory apparatus, the facial (CN VII) and chorda tympani nerves course through these segments of the temporal bone. The foramen lacerum transmits the greater superficial and deep petrosal nerves and a few small arterial branches. The carotid canal transmits the internal carotid artery as it runs parallel to the Eustachian tube on its way to the circle of Willis. The internal auditory canal contains CN VII and the CN VIII components (cochlear and superior and inferior vestibular nerves). The jugular foramen sits within the suture line between the temporal and occipital bones. Structures traversing this channel include the internal jugular vein, posterior meningeal artery, and CNs IX to XI. The stylomastoid foramen transmits the facial nerve to the parotid gland.