1988 Volume 91 Issue 2 Pages 240-246,321
Prior to the surgery of chronic otitis media it is desirable to know whether or not there is any pathology in the attic or aditus ad antrum that in blocking the aeration of the middle ear space peripheral to those areas, because if some pathology are present in the areas surgical intervention to them is often necessary. Various radiological methods including the tomography or CT have so far been used for this purpose.
The authors described a simpler and less time consuming method using tympanometry. In an ear with a perforation, the height of base line (compliance) of a tympanogram which normally represents the external ear canal volume in non-perforated ear, indicates the sum of the air volume contained in the external ear canal and the middle ear. In 56 ears (43 cases) with central perforations of the tympanic membranes (51 chronic otitis media, 5 traumatic perforations) a comparison was made between the compliance value and the CT findings of the ears. A very good correlation was found between the compliance value and the extent of the middle ear aeration estimated by the CT. While all the 33 ears with compliance values exceeding 2.0 cc were found to have clear attic and aditus ad antrum, 19 of 23ears with compliance values below 2. Occ and 17 of 18 ears with those below 1.5cc, were found to have aditus block.
It is concluded that tympanometry, less time consuming and simpler than radiological methods, is very effective in the preoperative screening of the patency of the attic and aditus ad antrum in chronic otitis media with perforation.
