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[Destruction of ossicular chain and its impact on hearing of patients with chronic suppurative otitis media].

OBJECTIVE
To study the characteristic of destructive ossicular chain and to evaluate integrity of ossicular chain and its impact on bone-conduction hearing of patients with chronic suppurative otitis media.


METHOD
The destruction of ossicular chain with microscopy during operation and the preoperative pure tone audiometry were observed in 148 patients (176 ears) with chronic suppurative otitis media.


RESULT
Destruction of ossicular chain was often observed in patients with chronic otitis media of cholesteatoma type, granuloma type and pars flaccid perforation of tympanic membrane. It initiated destructed malleo-incudal and incudostapedial joint for pars flaccid and pars tensa perforation of tympanic membrane respectively. Normal ossicular chain structure was observed in 52 ears. Destruction of ossicular chain was observed in 124 ears. Difference were significant for speech frequency air-conduction threshold and air-bone gap between group of normal ossicular chain and group of abnormal ossicular chain (P< 0.01). There was no difference for bone-conduction threshold between the above two groups.


CONCLUSION
Destruction of ossicular chain was often observed in patients with chronic otitis media of cholesteatoma type and granuloma type. The ossicular chain was normal in the patients who were both less than 40 dB in speech frequency air-conduction threshold and 30 dB of air-bone gap. The ossicular chain was destructed in the patients who were both over 55 dB in air-conduction threshold and 40 dB of air-bone gap. High frequency hearing loss was observed in patients with chronic suppurative otitis media.