Bone Auditory Thresholds Variations in Cholesteatoma Middle Ear Surgery

Abstract

Objective: To investigate the changes of bone auditory thresholds variations in cholesteatoma middle ear surgery and its related factors and its related factors. Methods: 122 cases (122 ears) of unilateral cholesteatoma otitis media were treated by mastoidectomy and/or tympanoplasty plus stage I tympanoplasty, and tragus cartilage ring-cartilage membrane (Referred to as cartilage group, 62 ears) and temporalis muscle fascia (Referred to as fascia group, 60 ears) were used as tympanic membrane grafts respectively. The changes of bone conduction hearing threshold were compared between the two groups before and 1, 3, 6 months and 1, 3 years after operation. And compare the difference in the incidence of ossicular chain fixation or necrosis, vestibular window or cochlear window dysfunction between the two groups of patients with increased (positive) and decreased (negative) bone conduction threshold before operation. Results: Compared with the healthy side, 95 ears of 122 ears in the two groups had higher bone conduction hearing threshold before operation. Among them, 48 ears were in cartilage group and 47 ears were in fascia group; In 72 ears (76.34%) of these cases, the bone conduction hearing threshold decreased after operation, and the difference between the two groups was statistically significant (P < 0.01). During operation, 57 ears (79.17%, 57/72) were found to have ossicular chain or two windows dysfunction, including 30 ears in cartilage group and 27 ears in fascia group. Of the 27 patients with normal hearing threshold, 5 had the above-mentioned lesions, including 3 in cartilage group and 2 in fascia group. Conclusion: The improvement of bone conduction hearing threshold in patients with cholesteatoma otitis media is mainly related to the fixation or necrosis of ossicular chain and the dysfunction of two windows. The tragus cartilage ring-perichondrium tympanoplasty can not only reduce the air-bone conduction difference, but also reduce the bone conduction hearing threshold, which has the advantage of stable and lasting hearing improvement.