[Destrution of ossicular chain and it's impact on hearing of patients with tympanosclerosis]

To study the destruction ossicular chain's impact on hearing of patients with tympanosclerosis.

A retrospective review was conducted in 115 patients with tympanosclerosis, all patients were divided into 3 groups, including normal ossicular chain structure (A group), fixed ossicular chain(B group), and interrupted ossicular chain (C group). The audiological feature of the patients were compared between the 3 group.

Difference were significant for PTA, 0.5, 1.0, 2.0, 4.0 kHz air conduction threshold between 3 group (P < 0.01). Difference were significant for air bone gap (ABG) between A, B groups and C group (P < 0.01), there was no difference for ABG between A and B group (P > 0.01). Difference were significant for air conduction threshold between 0.5, 1.0 kHz and 2, 4 kHz in A, B groups (P < 0.01), but there was no significant for same data in C group (P > 0.01). Difference were significant for average bone conduction, 1, 2, 4 kHz bone-conduction threshold between A group and B, C group (P < 0.01). The rate of Carhart notch was low and had no difference between 3 group (P > 0.01).

The ossicular chain was fixed in patients who's PTA > or = (54.31 +/-13.19) dB HL and was interrupted who's PTA > or = (63.90 +/- 20.29) dB HL or ABG > or = (33.23 +/- 8.49) dB HL. The rising shaped curve in air-conduction audiograph may indicate the ossicular chain was fixed,and the smooth shape curve may indicate the ossicular chain was interrupted.