Abstract:

Objective The false sensorineural loss caused by otosclerosis due to stapes fixation is known as the Carhart notch. To examine the changes in air-bone gap (ABG) and bone-conduction (BC) hearing thresholds by comparing the preoperative and postoperative audiometry results in patients with chronic otitis media (COM), to investigate the effects of air conduction (AC) on BC, to determine the effects of postoperative improvement in AC on BC, to detect the presence of the Carhart notch in COM, and to determine the effects of surgery on the Carhart notch. Material and Methods A total of 104 patients who underwent type 1 tympnoplasty between January 2012 - March 2017 in our clinic were included in this retrospective study. Parameters measured during the preoperative and postoperative sixth month audiometric evaluation comprised AC hearing thresholds at the frequencies of 250-8,000 Hz, BC hearing thresholds at 500-4,000 Hz, and ABG values at 500-4,000 Hz intervals. Results Before surgery, the Carhart notch was present in 46 (44.2%) of the 104 patients. Postoperatively, the Carhart notch was observed to have been corrected in 25 (54.3%) of these patients (p=0.029). Conclusion After tympanoplasty, significant improvement in ABG may lead to improvement in BC at 2,000 Hz in COM cases with an intact and mobile ossicular chain. The Carhart notch may also be present in COM.