The Size Of The Middle Ear And The Mastoid Air Cell: System Measured By An Acoustic Method

Abstract

The total volume for the middle ear and mastoid air cells was measured in 55 temporal bones with normal ear drums from a Norwegian post-mortem material. The measurements were made by an acoustic method and checked by means of fluid filling induced by vacuum pumping. As a measuring fluid X-ray contrast medium was employed so that the degree of filling could be examined by X-ray. The volume varied between approximately 2--22 cm3 with an average round 6,5 cm3.