慢性化脓性中耳炎的听骨链病变及对听力的影响

目的:探讨慢性化脓性中耳炎的听骨病变特点、听骨链完整性的判断及对骨导听力的影响.方法:对148例(176耳)慢性化脓性中耳炎患者行术前纯音测听,术中显微镜下观察听骨链病变.结果:骨疡型、胆脂瘤型中耳炎和鼓膜松弛部穿孔者听骨链多有破坏,松弛部穿孔先破坏锤砧关节,紧张部穿孔先破坏砧镫关节.慢性化脓性中耳炎听骨链完整、活动好52耳,听骨链中断或固定124耳.听骨链完好与听骨链病变者语频段气导听阈、气骨导差比较均差异有统计学意义(均P＜0.01).语频段骨导听阈比较无差异,两者高频骨导听阈均提高.结论:骨疡型、胆脂瘤型中耳炎听骨链多有破坏.语频段气导听阈在40 dB以内,气骨导差在30 dB以内者,听骨链大多完好.气导听阈在55 dB以上,气骨导差在40 dB以上者,听骨链多有中断或固定.慢性化脓性中耳炎可伴有高频骨导听力下降.

Destruction of ossicular chain and it's 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 it's 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 flaccida perforation of tympanic membrane.It initiately destructed malleo-incudal and incudostapedial joint for pars flaccida 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.