Mastoiditis is a disease that many people experience. But not everyone knows what the mastoid processes are, and where they are. What is the structure of this part of the temporal bone? How dangerous is inflammation of these structures, and what can cause the disease? Many people are interested in these issues.
Where are the mastoid processes?
The mastoid process is the lower part of the temporal bone. If we talk about its location, then it is located below and behind the main part of the skull.
The process itself has the shape of a cone, the base of which borders on the area around the middle cranial fossa. The apex of the process is directed downward - some muscles are attached in it, in particular the sternocleidomastoid muscle. The base of the cone borders the hard shell of the brain (which is why infectious inflammation of this area is so dangerous, because pathogenic microorganisms can penetrate directly into nerve tissues).
In the subcutaneous tissue, which covers this part of the temporal bone, there are lymph nodes and vessels, the behind-the-ear vein and artery. Here, branches of the small and large ear nerves pass .
It is worth noting that the mastoid processes can have a different shape. In some people they are long with a narrow warp, in others - short, but with a wide base. This anatomical feature largely depends on genetic heredity.
The structure of the mastoid process
As already mentioned, this part of the temporal bone resembles a cone in shape. In modern anatomy, it is customary to distinguish the so-called Shipo triangle, which is located in the anteroposterior part of the appendix. The posterior triangle is bounded by a mastoid crest, and in front of it the border extends at the posterior part of the external auditory canal.
The internal structure of the process is somewhat reminiscent of a porous sponge, since there are many hollow cells, which are nothing more than airborne appendages of the tympanic cavity. The number and size of such cells can be different and depends on the characteristics of the growth and development of the body (for example, inflammation of the ear in childhood leaves its mark on the structure of the mastoid process).
In the area of the Shipo triangle is the largest cell, called the antrum or cave. This structure is formed due to close interaction with the tympanic cavity and is present in each person (unlike smaller cells, the number of which can vary).
Types of mastoid processes
As already mentioned, the mastoid process of the temporal bone can have a different internal structure. In the first year of an infant's life, an antrum is formed. Up to three years, there is an active pneumatization of the internal tissues of the appendix, which is accompanied by the appearance of hollow cells. By the way, this process lasts throughout a person’s life. Depending on the number and size of cavities, it is customary to distinguish several types of structure:
- Pneumatic mastoid processes are characterized by the formation of large cells that fill the entire inner part of this bone structure.
- With the sclerotic type, there are practically no cells inside the process.
- In the diploetic mastoid process there are small cells that contain a small amount of bone marrow.
It is worth noting that most often doctors find traces of the mixed formation of cavities in this part of the temporal bone. Again, it all depends on the genetic characteristics of the body, the pace of development, as well as the presence of injuries and inflammatory diseases in childhood and adolescence.
Inflammation of the mastoid process and its causes
A disease in which inflammation of the tissues of the mastoid processes is observed is called mastoiditis. The most common cause is infection, and pathogens can enter this area of the skull in different ways.
Most often, such a disease develops against the background of otitis media. The infection enters the mastoid process of the temporal bone from the tympanic cavity or ear canal. In some cases, inflammation develops with a direct skull injury in the temple or ear. The source of infection can be inflamed lymph nodes located in this zone. Much less often, the cause of the disease is systemic blood poisoning.
The main symptoms of inflammation
The main signs of mastoiditis largely depend on the severity and stage of development of the disease. For example, in the initial stages it is very difficult to distinguish inflammation of the mastoid process from ordinary otitis media.
Patients complain of sharp, shooting pain in the ear. There is an increase in temperature, weakness and aches in the body, headaches. Appears from the ear canal.
In the absence of therapy or insufficient treatment (for example, stopping antibiotics too quickly), the clinical picture changes. The mastoid process of the ear is gradually filled with pus, and under pressure the bony septum between the cells is destroyed. The skin and subcutaneous tissues behind the auricle swell and redden, become hard, hot to the touch. Ear pain becomes stronger, and thick purulent masses stand out from the ear canal.
Inflammation from the cavities of the mastoid process can spread under the periosteum - pus accumulates already in the layer of subcutaneous tissue. Quite often, the abscess breaks on its own, as a result of which a fistula forms on the skin.
How dangerous can a disease be? The most common complications
As already mentioned, the mastoid is located behind the ear and borders on important organs. Therefore, the lack of timely therapy is fraught with dangerous consequences. If the focus breaks into the cavity of the middle and inner ear, labyrinthitis develops. Inflammation of the inner ear is accompanied by tinnitus, hearing loss, as well as damage to the balance organ, which leads to impaired coordination of movements.
Mastoid processes border the hard membranes of the brain. Infection can spread to nerve tissue, leading to the development of meningitis, encephalitis, and sometimes abscesses.
Infection into the vessels responsible for the blood circulation of the brain is dangerous - this is fraught not only with inflammation of the vascular walls, but also with the formation of blood clots, clogged arteries, and even death.
Complications of mastoiditis include facial nerve damage. After all, the mastoid process behind the ears is very close to the nerve fibers.
How is mastoiditis treated?
As you can see, mastoiditis is an extremely dangerous disease, so adequate therapy is simply necessary here. Any delay and attempts at self-medication can lead to a lot of dangerous complications.
As a rule, treatment is carried out in a hospital, where the doctor has the opportunity to constantly monitor the patient's condition. Patients are prescribed intravenous antibiotics to help fight bacterial infections. In addition, it is necessary to create conditions for the free exit of purulent masses from the ear canal.
When is trepanation of the mastoid process necessary?
Unfortunately, conservative therapy is effective only in the initial stages of mastoiditis. If pus began to accumulate in the cavities of the lower part of the temporal bone, then simple surgery is necessary. Trepanation of the mastoid process begins with the opening of the bone wall of the process. After that, the surgeon with the help of tools cleans the tissues of pus, treats them with antiseptics and antibacterial solutions. Then a special drainage system is installed, which provides easy and quick removal of secretions, as well as local administration of antibiotics.