The temporal bone is what medicine refers to as a symmetrically laid out and extremely detailed cranial bone. The temporal bone is an important part of the skull base and serves to stabilize the skull and house sensitive structures. A temporal bone fracture can occur as part of a skull base fracture.
What is the temporal bone?
The temporal bone is a cranial bone located in the lateral posterior region of the skull. The structure is symmetrically present on both sides of the human skull. In medical terminology, the temporal bone is called the os temporale and makes up one of the most differentiated bones in the human body. Many structures of the middle and inner ear are located in the temporal bone. The Os temporale is even involved in the temporomandibular joint as a socket. The temporal bone is differentiated into four parts. In addition to the temporal bone scale (pars squamosa ossis temporalis)and the tympanic part (pars tympanica ossis temporalis)it contains a mastoid process with mastoid cells (pars mastoidea ossis temporalis) and the so-called petrous bone (pars petrosa ossis temporalis). The temporal bone is connected to the adjacent bones by sutures. The other structures of the temporal bone are wedged and fixed by connective tissue between the occipital bone, the sphenoid bone, the temporal bone scale and the parietal bone. In animals, these structures are also called the petrous pyramid because of their arrangement.
Anatomy and structure
The scalene is the largest section of the temporal bone in area and is involved in the lateral wall of the cranial cavity. Anteriorly, it carries the zygomatic process (processus zygomaticus ossis temporalis) of the zygomatic arch (arcus zygomaticus). Posteriorly, the zygomatic arch forms a ledge for the scale and extends over the entire surface of the scale. The articular surface of the temporomandibular joint (mandibular fossa) is located on the zygomatic process. The tympanic part of the temporal bone encircles the auditory canal (porus acusticus externus) and participates in the lateral wall of the tympanic cavity (cavum tympani)and the tympanic cavity (cavum tympani). The structure also forms the bony enclosure of the styloid process. A fissure (fissura petrotympanica) separates the tympanic part from the rock part. The mastoid part has a hollow and mucosal mastoid process (Processus mastoideus). An opening (aditus ad antrum) connects the structure to the tympanic cavity. In addition, there is connection to the hollow and air-filled mastoid process cells (cellulae mastoideae), which are connected to the nasopharynx via the middle ear. The petrous bone is the hardest skull bone and includes the inner ear.
Function and tasks
Although the petrous bone does not perform any active functions, it is an irreplaceable part of the base of the skull, providing stability and housing important structures in the head. It provides stability to various sensory organs and nerves in the head section and also provides bony protection for delicate structures. For example, in the cleft between the tympanic section and the rocky section of the temporal bone lies the tympanic cord (chorda tympani) of the facial nerve (nervus facialis). Many cranial nerves also enter the skull through the temporal bone through the holes and openings, which are kept safe and stable thanks to the bones of the structure. The furrows of the temporal bone serve as a guide rail for various nerves and vessels. The anatomical structure is also perfectly aligned with the organ of hearing. Deformities of the temporal bone can therefore have an extremely negative effect on hearing. The temporal bone is also the attachment point of various muscles. For example, the mastoid process of the anatomical structure provides attachment for the long neck muscles (sternocleidomastoid muscle). Furthermore, since the temporal bone is involved in the temporomandibular joint, it indirectly plays a role in human food intake and comminution. Thus, although the cranial bone itself is a passive structure, many head structures located within it perform irreplaceable tasks in perception, innervation, and motor function. For this reason, injuries or malformations of the cranial bone can affect a wide variety of bodily functions that, at first glance, may not be associated with the bony structure by the layperson.
Diseases
In diseases such as Eagle syndrome, there is a deformity of the temporal bone. The stylar process of the anatomic structure is over 30 mm long in Eagle syndrome.The removal of the tonsils is currently being discussed as the cause of the syndrome. Most often, those affected suffer from sore throat. A foreign body sensation or globe syndrome in the throat may also occur. Pain in the throat is just as conceivable as a pressure pain in the tonsillar fossa. Painful sensations occur especially during swallowing and neck movements. Atypical facial pain is also among common symptoms. The incidence of Eagle syndrome is relatively high, with many affected individuals remaining without noticeable symptoms. The situation is different for a fracture of the skull bone. This accident-induced phenomenon can cause inner ear damage, for example, which can progress to inner ear deafness. Inflammation of the temporal bone can also occur. These inflammations usually affect the mucous membranes of the anatomical structure. The mastoid process of the temporal bone in particular is also a popular target for bacterial infections, which often spread from there to the ear. Ear infections with discharge can be the result. Tumor diseases can also occur in the temporal bone area. One of these is the so-called paraganglioma, which does not arise directly from the temporal bone, but occurs in its immediate vicinity. These tumors are the most common tumors of the middle ear area. Overall, however, they occur comparatively rarely. They arise from the nerve nodes of the middle ear and cause nonspecific symptoms.
