Correlation between hearing loss and middle ear volume in patients with a tympanic membrane perforation

Abstract

Objective To investigate a possible correlation between the degree of conductive hearing loss (CHL) caused by an isolated tympanic membrane (TM) perforation and mastoid‐middle ear volume. Study Design Retrospective chart, audiometry, and computed tomography (CT) imaging review. Methods Adult patients with a diagnosis of isolated TM perforation between 2010 and 2018 were identified and their audiometric data collected. Mastoid‐middle ear volume (MMEV) was then calculated based on segmentation analysis from the patient's head or temporal bone CT. Calculated MMEV was compared to MMEV derived by tympanometry. A Student's t‐test was performed to determine a correlation between the calculated MMEV on CT imaging and the degree of conductive hearing loss as measured by the air bone gap on standard audiometry. Results There was a statistically significant difference between MMEV as determined by segmentation analysis compared to that determined by tympanometry (absolute average percent difference = 33.8%; range ‐49.5% to +155.2%; P = .03). Greater MMEV determined by segmentation analysis correlated with smaller air bone gap; this trend approached but did not reach statistical significance (P = .09). Conclusions Calculated MMEV by segmentation analysis on CT imaging may be a more accurate estimate of MMEV than tympanometry. MMEV may be correlated to the degree of conductive hearing loss in the setting of isolated TM perforation where greater volume was associated with better hearing. Level of Evidence 4 Laryngoscope, 130:E228–E232, 2020

Effects of mastoid and middle-ear volume on graft success and hearing outcomes in paediatric tympanoplasty

“…Casale et al . 20 compared the mastoid–middle-ear volume calculation technique in temporal bone high-resolution CT with tympanometry, and revealed that radiological measurements were more reliable in this calculation.…”

“…Casale et al . 20 evaluated the relationship between mastoid–middle-ear volume and conductive hearing loss in patients with an isolated tympanic membrane perforation, and showed that hearing loss incidence was higher in ears with a small mastoid–middle-ear volume compared to those with a large volume. Similarly, Mehta et al .…”

“…The anatomical structure of mastoid cells poses a challenge to accurately measuring the volume; however, 3D measurement techniques have enabled the calculation of true volume. Casale et al 20 compared the mastoid-middle-ear volume calculation technique in temporal bone high-resolution CT with tympanometry, and revealed that radiological measurements were more reliable in this calculation.…”

Correlation between tympanometry volume and three-dimensional computed tomography mastoid volumetry in tympanoplasty candidates

“…Previous studies have already assessed the correlation between tympanometry and plain X-rays or CT scans, and they reported mixed results. 7,8 Plain X-rays are of historic and rather limited use in the calculation of mastoid air cells today because CT allows a much more detailed view. However, computed tomography scans greatly vary in resolution size from slices as thin as 0.1 mm (cone beam CT) to thicker slices of 2.5 mm.…”

“…Such low-resolution CT scans were used in previous studies. 8 Yet, in lower resolution scans, small mastoid air cells may not be detected properly and are omitted during the overall calculation process. High-resolution sub-millimetre CT scans are preferred to evaluate temporal bone pathologies.…”