The mastoid antrum, also known as the tympanic antrum, is a small cavity located near the middle ear. It is connected to the mastoid process, which is a bony protrusion behind the ear. Other synonyms for the mastoid antrum include the mastoid air cells and the epitympanic recess. These terms are often used interchangeably by healthcare professionals to refer to the same anatomical structure. The mastoid antrum plays an important role in the functioning of the auditory system, as it helps to regulate the pressure within the middle ear and drain excess fluid. Understanding the various synonyms for this structure can assist in effective communication between medical professionals and patients.