(An) influence ofchronic otitis media to bone conduction
[영문]Classically the hearing loss described in conditions of chronic otitis media and mastoiditis has been a loss in the conductive component of hearing only, but for sometimes certain cases had evidence of a cochlear lesion as demonstrated by decreasing bone conduction acuity. The patients of chronic otitis media with bone
conduction loss influence largely even after tympanoplasty in order to restore hearing acuity, and we can foresee postoperative prognosis.
This study was designed to investigate the relation of cochlear function in chronic otitis media.
Author obtained following conclusion through 189 cases who had Middle ear surgery under the diagnosis of chronic otitis media at department of otolaryngology, Severance Hospital during 1 April of 1973 to 31 March of 1974.
Preoperatively bone conduction as pure tone audiometric examination were measured in 500 HZ, 1,000 HZ, 2,000 HZ and 4,000 HZ freguencies, and the relativity of these results to illing duration, age distribution, type of operation, and existences of
cholesteatoma and stapes were discussed.
1. Duration of illness is getting longer, each measured frequency's bone conduction is getting more decrease, accordingly case of over 21 years of duration group shows it mostly decreased 14.8dB to 20.0dB than 1 to 5 years of duration group.
2. According to the age, older group shows more decreased, and it also loss of hearing differences between 1 to 10 and 31 to 41 years group of bone conduction are 22.8dB to 25.6dB.
3. According to type of operation, the loss of bone conduction in advanced surgery brought the more decreased bone conduction. Loss of hearing differences between myringoplasty and radical mastoidectomy are 30.9dB to 35.6dB.
4. Cholesteatoma influenced to the worsed bone conduction, and the longer illing duration also related to the more worsed difference of bone conduction as 23.0dB to 25.0dB at over 21 years duration group.
5. The cases of ossicular chain disrupted as absence of stapes are showed more decreased bone conduction than the cases of existing of stapes, and the longer illing duration also influenced to the more worsed difference of bone conduction as
18.4dB to 23.8dB over 21 years duration group.