A mastoidectomy is surgery to remove cells in the hollow, air-filled spaces in the skull behind the ear. These cells are called mastoid air cells.
The surgery used to be a common way to treat an infection in the mastoid air cells. Such infection usually resulted from an ear infection that spread to the nearby bone in the skull.
Mastoidectomy is now rarely needed, because infections are commonly treated with antibiotics.
However, this surgery may be used to treat other problems, such as: