Introduction
As the name suggests, the mastoid air cells are a group of air-filled cells (pneumatized cells) that represent the empty bone space of the temporal bone, specifically in the mastoid part. These mastoid air cells, also called cellular mastoids, are of different sizes and have various extensions. These mastoid cells are seen from birth due to the fusion of the bones of the skull, and the completion lasts up to six years of life. The mastoid air cells act as a gas reservoir in the middle ear, acting as a buffer that leads to the production of pressure and creates a higher volume and surface area ratio. These cells thus help balance the internal air pressure and the atmosphere. However, these cells can create pressure when an infection in the upper respiratory tract occurs.
How Is the Structure of the Mastoid Cells?
At birth, the Petro mastoid portion of the temporal bone gives rise to the mastoid process, which fuses with the squamous zygomatic and tympanic portions of the temporal bone. The mastoid process begins to grow more quickly between the ages of two and five and is finished by the age of six. Through the mastoid and aditus ad antrum, mastoid air cells can communicate with the middle ear. The Koerner septum, a narrow bony structure generated by the petro-squamous (flat) suture that extends posteriorly from the epitympanum, divides the mastoid air cells into medial and lateral compartments. It passes through the mastoid air cells. The air cells in the superior and anterior parts of the mastoid process are large, irregular, and contain air; however, as they move toward the inferior section, they become smaller, and the air cells at the apex of the process are often fairly small, containing marrow. Sometimes, they are completely missing.
What Are the Functions of Mastoid Air Cells?
Mastoid cells help in various functions of the ear, and they are:
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Balancing the external and the internal temperature by stimulating the ears (vestibular stimulation): this is achieved by stimulating the gas-filled mastoid cells to be an isolating material to seal the temperature.
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Balancing the pressure of the middle ear.
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Creates a bi-directional pathway between the ear and the external gas.
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It helps in expelling and locally reabsorbing the physiological fluids present in the ear.
What Is Mastoid Air Cell System?
It was recently established that the mastoid air cell system (MACS) is a part of the middle ear cleft, which plays an important part in the origin, course, and nature of behavior, providing clarity of middle ear inflammatory illnesses. Pneumatization is the process by which the epithelium enters the developing bone and creates air cell chambers lined with epithelium. Even though MACS's exact function is unknown, several studies show that its volume inversely correlates with some middle ear degenerative diseases, such as cholesteatoma and otitis media etc. Because of this, the skeletal complexity of MACS airflow creates a few challenges for the complete evaluation. The mastoid air cell system has a major influence on middle ear physiology. According to Tumarkin and Holmquist et al., the mastoid air cells serve as the middle ear's air reservoir and aid in controlling middle ear pressure. Sade was in favor of the concept. The mastoid air cells have closer interactions between blood vessels and the mucosal basement membrane than other middle ear areas. According to Okubo, the nasal and lung membranes, which are in charge of gas transport and outflow, and the histological anatomy of a human mastoid cell are very comparable.
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Otitis Media: Otitis media is a condition where the middle ear cleft, which is composed of the tympanic cavity, aditus antrum (ear aperture), mastoid air cell system, and eustachian tube (ear tube), becomes inflamed. Otitis media is classified into two types based on its occurrence: acute and chronic. Here, the development of temporal bone and inflammatory changes in the middle ear mucosa in children may result from middle ear infections, which in turn control the pneumatization of the mastoid bone. The genetic theory research states that heredity factors in the degree of mastoid pneumatization. There has been much discussion over the years on whether the underdeveloped mastoid is an inherited condition or the outcome of acute otitis media in childhood.
What Are the Factors Affecting Mastoid Air Cell System?
The factors affecting the function of the mastoid air cell system are:
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Genetic Factors: Genetic factors play an important role in the structure and functioning of the mastoid air cells. Any gene disruption can lead to improperly developed bone cells and various medical complications.
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Adolescence: As this is the age of growth and maturation, an underdeveloped bone precedes many common infections.
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Environmental Factors Like High-Pressure Environments: Environmental factors and genetic factors are also very important as they determine the capacity of air-filled bone cells in the mastoid antrum.
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Inflammation of the Inner Ear Tube: It is seen that the amount of pneumatization of the bone depends on the presence of any infection or inflammation of the mastoid bone.
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Large Mastoid Process (Acromegaly): The size of the bone influences the pneumatization of the mastoid air cells. Here, smaller cells are seen to hold more pneumatized cells than larger ones.
Conclusion
In conclusion, the tiny and connected areas inside the mastoid bone behind the ear are called mastoid air cells. These mastoid cells help improve sound conduction and protect important tissues like the inner ear. These air-filled chambers are also involved in many other tasks, especially in maintaining equilibrium and balance of the body, for which they are essential. Any bacterial infection that can cause inflammation and discomfort is called mastoiditis and requires diagnosis and treatment with an understanding of the structure and function of mastoid air cells. These cells also function as significant landmarks for temporal bone-related surgical procedures. Regarding hearing, balance, and navigating our environment, these mastoid air cells play an important role in caring for the systems responsible for body balance and hearing. However, these mastoid air cells become dead (sclerotic) when air flow or ventilation is lacking.
