The mastoid process is a part of the temporal bone, making it one of the bony structures at the base of the skull. The structure is also known as the mastoid process and provides an attachment point for many muscles. Because of air-filled connections to the middle ear, the region is often involved in middle ear infections; this phenomenon is known as mastoiditis.
What is the mastoid process?
Pneumatization refers to a structural feature of bone. Pneumatized bones are equipped with air-filled cavities. In medicine, the term plays a role primarily for the architecture of the bones of the skull. One pneumatized bone part is the processus mastoideus of the os temporale. The Os temporale is the temporal bone, which is counted among the bones of the skull and is involved in the temporomandibular joint as well as the inner and middle ear. The processus mastoideus is a type of bony prominence of the pneumatized temporal bone. Males usually possess a stronger Processus mastoideus than the female gender. Anatomically, the Processus mastoideus is located in the posterior portion of the Os temporale. Thus, the bony or mastoid process is located directly behind the ear and is present on both sides of the body.
Anatomy and structure
The proessus mastoideus is composed of air-containing cells that are in direct communication with the middle ear. The surface structure of the mastoid process turns out to be rather rough. The site of the os temporale is connected with different muscles, especially with the sternocleidomastoid muscle, the splenius capitis muscle, the longissimus capitis muscle and the digastricus muscle, the attachment of which is formed by the mastoid process. The mastoid of the anatomical structure is highly pneumatized. The pneumatization spaces consist of mastoid cells or cellulae mastoideae, the expression of which is subject to individual differences. In the cranial part of the mastoid process, the individual pneumatization spaces are much larger than in the caudal part of the structure. The caudally located spaces communicate with the aditus ad antrum, or tympanic cavity, through the antrum mastoideum. Like many other pneumatization spaces of the skull, those of the processus mastoideae are partly covered by mucosal tissue.
Function and Tasks
Active tasks are not performed by the mastoid process any more than by the larger structure of the os temporale. However, as a portion of the cranial bone, the mastoid process is an indispensable element of the skull base and stabilizes the cranial structures. Important structures of the head are housed in the temporal bone. Sensory organs and nerves of the head section receive stability through the os temporale. The individual portions of the temporal bone form a bony protection for the sensitive structures. Holes and openings exist for the cranial nerves, which enter through the temporal bone into the skull. Furrows in the os temporale serve as guide rails for the brain-supplying nerves and vessels. The mastoid process of the os temporale plays a major role with its structure, especially for the auditory organ. The anatomy of the mastoid process is directly tuned to auditory perception and is thus involved in auditory sensory input in a passive way. In addition, the mastoid process of the temporal bone provides an important attachment point for muscles such as the long neck muscles. The region around the mastoid process is also referred to as the occipital region in different literature. The occipital artery and vein as well as the greater occipital nerve come to the surface in the course of the mastoid process, so that the pulse is palpable in this region. Thus, although the mastoid process does not perform any active functions, it plays an essential role for a wide variety of anatomic structures of the cranial region, providing attachment to them or assuming a mediating function.
Diseases
One disease with accompanying pain symptoms in the region of the mastoid process is migraine. This is a neurologic disorder characterized by periodic, recurrent, seizure-like, pulsating, and often hemiplegic headache. Accompanying symptoms may include nausea to vomiting, sensitivity to light, and sensitivity to sound. Optical and sensory perception disorders may also be present in the context of migraine. Motor disorders are also conceivable.Migraine patients often localize the recurrent pain in the occipital region of the mastoid process. In addition to hormonal factors, stress, nutritional factors, sleep, and environmental stress play a causally significant role in migraine disease. In addition to migraine, the so-called mastoiditis can give clinical relevance to the mastoid process. This disease is an inflammatory process that is due to an infection. As a rule, mastoiditis develops as a complication of otitis media acuta, i.e., an acute inflammation of the middle ear. Mastoiditis thus usually corresponds to a bacterial infection with pathogens such as pneumococci, Haemophilus influenzae type B or streptococci and staphylococci. Viral infections with rhinoviruses, coxsackieviruses, influenza viruses or adenoviruses are also conceivable primary causes of the inflammatory process. After a weakening of the defense system, the organism is particularly susceptible to bacterial pathogens. Bacteria penetrate the nasopharynx and reach the middle ear, where they cause otitis media. If this middle ear infection is treated incorrectly, inadequately, or not at all, the bacteria migrate to adjacent structures such as the mastoid process, which communicates with the middle ear via air-containing cells. Bacterial or viral colonization of the process is usually accompanied by symptoms such as earache and thirst sensitivity. Usually these early symptoms are later associated with fever, sleep disturbances or inner restlessness. Pain as well as swelling around the mastoid process may also be symptomatic, as may discharge from the ear or general signs of infection such as loss of appetite.
