Assessment of eustachian tube function and middle ear pressure changes in patients with Oral Submucous Fibrosis (OSMF)

Background: Oral submucous fibrosis (OSMF) is a chronic, potentially malignant condition prevalent in the Indian subcontinent, characterized by fibrotic changes in the oral mucosa that may extend to the pharynx and larynx, leading to symptoms like trismus, dysphagia, and ear discomfort. Previous studies suggest that OSMF-related fibrosis of palatal and paratubal muscles may impair eustachian tube function, potentially causing middle ear pressure changes or conductive hearing loss, though findings remain inconsistent, particularly across regional populations. Objective: This study aimed to evaluate eustachian tube function (ETF) and middle ear pressure dynamics in OSMF patients from Southern India, hypothesizing that fibrosis alters middle ear pressure without significantly affecting conductive hearing loss. Methodology: Thirty clinically confirmed OSMF cases and 30 age- and sex-matched healthy controls underwent pure tone audiometry, tympanometry, and ETF tests using standardized equipment. Results: Middle ear pressure values (pressure at normal condition [PNC] and pressure after Valsalva maneuver [PV]) were significantly reduced in OSMF patients (PNC: -23.75 ± 43.76 daPa, PV: 0.60 ± 58.19 daPa) compared to controls (PNC: -1.11 ± 61.55 daPa, PV: +43.18 ± 80.36 daPa; p = 0.023 and p = 0.002, respectively), indicating altered eustachian tube dynamics. However, no significant conductive hearing loss was observed (1.66% of OSMF ears vs. 0% in controls; p > 0.05). Conclusion: OSMF is associated with subtle middle ear pressure changes, and fibrosis of paratubal muscles may be a possible contributing factor but does not significantly impact conductive hearing, suggesting a need for ENT monitoring in OSMF patients for subclinical effects.