Does the Location of a Small Tympanic Membrane Perforation Affect the Degree of Hearing Loss in Adult Patients with Inactive Mucosal Chronic Suppurative Otitis Media?

Background: Tympanic membrane perforation due to inactive mucosal chronic suppurative otitis media is a common problem in otolaryngology, with consequent conductive hearing loss. Still, there is controversy about the relationship between the location of the tympanic membrane perforation and the degree of hearing impairment.

Aim of the study: To assess the correlation between the location of a small tympanic membrane perforation and the degree of conductive hearing loss in adult patients with inactive mucosal chronic suppurative otitis media.

Patients and methods: A prospective cross-sectional study enrolled 74 adult patients with small tympanic membrane perforations (perforation involves less than one quadrant of the tympanic membrane) and conductive hearing loss (airbone gap ≥ 20 dB HL) due to inactive mucosal chronic suppurative otitis media for at least 3 months. The locations of the tympanic membrane perforations were classified as anterosuperior, anteroinferior, posterosuperior, and poster inferior perforations. Audiometric analysis and a CT scan of the temporal bone were done for all patients. The means of the air and bone conduction pure tone hearing threshold averages at frequencies 500, 1000, 2000, and 4000 Hz were calculated, and consequently, the air-bone gaps were calculated and presented as means. The ANOVA test was used to compare the means of the air-bone gaps, and the Scheffe test was used to determine if there were statistically significant differences regarding the degree of conductive hearing loss in relation to different locations of the tympanic membrane perforation.

Results: The ages of the patients ranged from 20 to 43 years (mean = 31.9 ± 6.5 years), of whom 43 (58%) were females and 31 (42%) were males. The means of the air-bone gaps were 32.29 ± 5.41 dB HL, 31.34 ± 4.12 dB HL, 29.87 ± 3.48 dB HL, and 29.30 ± 4.60 dB HL in the posteroinferior, posterosuperior, anteroinferior, and anterosuperior perforations, respectively. Although the air-bone gap's mean was greater in the posteroinferior perforation, statistical analysis showed that it was insignificant (P-value=0.168).

Conclusion: In adult patients with inactive chronic suppurative otitis media, the anteroinferior quadrant is the most common location of the tympanic membrane perforation, and there was an insignificant correlation between the location of a small tympanic membrane perforation and the degree of conductive hearing loss.