Cholesteatoma Otitis Research Articles

Hearing test for conductive deafness

test has become important for tympanoplasty because it indicates the location of lesion and predicts postoperative hearing. However the basic knowledge has not yet been accumulated enough to establish this method. Therefore, the author measured the mechanical characteristics of a nylon which was attached to a bone conduction receiver. It was found that this Sonde was hardly influenced by the pressure when it was pressed on the subject's ear drum, Moreover, this Sonde had no appreciabie amolitude distortion. Then the author carried out hearing test using this Sonde in 136 cases of conductive deafness. This Sonde was proved to be available in clinical use because of little pain in its application to the ear drum. Hearing loss measured by the Sonde corre- sponded with air conduction loss in cases of oto- sclerosis and pseudo-otosclerosis in which the mobi- lity of the ossicular chain was affected. On the other hand, hearing loss measured by the Sonde did not always correspond with air conduction loss in adhesive otitis, cholesteatoma otitis, and chronic suppurative otitis. This fact depended upon whe- ther the mobility of the ossicular chain was affe- cted in these cases or not. When the ossicular chain was intact in mobility, no hearing loss was detected by the Sonde and vice versa. Therefore, when hearing loss by the Sonde was more than 20 dB, it was diagnosed as the disorders of the ossi- cular chain. But when hearing loss was within 20 dB, the ossicular chain was regarded as intact or as of the type of continuity by the connective tissue. In this case liquid-conduction test and the test using the artificial ear drum should be applied to confirm the diagnosis made by Schallsonde test'

MASTOID OSTEOPLASTY WITH ANORGANIC BONE.

The authors have tested the suitability of Ossar® (Laake Oy, Turku, Finland) which is a bovine bone, treated with ethylenediamine, as a filling substance for bone cavities arising after surgical treatment of chronic otitis. The preparation was used in the cases of 47 patients, 18 of which had been operated on for cholesteatomatous otitis and 23 for other kinds of chronic otitis; 4 had been re-operated on for suppurating radical cavities, one for chronic mastoiditis and one for adhesive otitis. All the patients were subjected to reconstruction of the external auditory meatus, according to Palva's method, and the empty space remaining behind the musculoperiosteal patch was filled with Ossar® granules. Postoperative recovery was uneventful, and the results were followed for 6 to 12 months after the treatment. None of the ears required re-operation due to infection caused by Ossar®, as a rule the external auditory meatus retained its shape, and no cavities were formed behind the ear. In two instances, a histo...