Brief Answer:
It means an air filled cavity. Which is perfectly normal.

Detailed Answer:
Hi

Thanks for posting the query

The pneumatization or the air filled cavity of the mastoid is normal. If the ear has to work perfectly then, the middle ear cleft (the areas including Eustachian tube, middle ear and the mastoid) has to be well ventilated. Hence, the air spaces are very important for the normal physiological function of the ear.

When the ear gets infected repeatedly then, the air spaces in the mastoid cavity are destroyed and gradually replaced by a harder bone known as sclerotic bone.

Hope this answers your query. Revert back to me if you have any follow up queries.

Regards
Dr. Naveen Kumar N
ENT and Head & Neck Surgeon

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Brief Answer:
Under pneumatization means reduced air spaces in the mastoid...

Detailed Answer:
Hi

Thanks for writing back

As explained to you in my earlier response, under pneumatization is a condition wherein the normal air pockets/spaces are reduced due to the presence of fluid/secretions/hard bone.

According to the image posted by you, the circled area is a well-pneumatized left mastoid (seen as a dark area inside the mastoid) which is perfectly normal. The corresponding mastoid on the other side is having mixed cellularity due to the presence of edematous mastoid mucosa/secretions/calcium deposition, thus, reducing the air spaces.

Under pneumatization could be secondary to a recurrent block in the Eustachian tube (the tube connecting nose and the ear) or infection in the middle ear cleft (otitis media).

Hope this clarifies your doubts. I will be available for your further queries.

Regards
Dr. Naveen Kumar N.
ENT and Head & Neck Surgeon

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