Comparative Evaluation of Eustachian Tube Changes in Oral Submucous Fibrosis Patients.

Oral submucous fibrosis (OSMF) is a potentially premalignant disorder affecting the oral cavity and its adjacent structures. The present study was aimed at a comparative evaluation of eustachian tube (ET) changes in OSMF patients using audiometry and cone-beam computed tomography (CBCT).  A total of 40 patients who were clinically diagnosed with OSMF were taken for the study and were graded into clinical and functional staging. After grading, the patients were subjected to audiometry to evaluate their hearing deficit. Subsequently, the patients were subjected to CBCT analysis for the evaluation of the length and volume of the ET. The length of ET was measured in the axial sections of the full-face CBCT images taken at the level of the root tip of the upper first molar. The radiolucency from the nasopharyngeal opening to the maximum distance was considered. The volume of ET was measured using third-party software (ITK-SNAP) in the radiolucent area.  The age group in which a higher number of OSMF cases were seen was between 41 and 50 years. There was mild to moderate hearing loss observed in the right and/or left ear, with little variation between right and left ear changes in audiometry. The CBCT analysis did not show a significant difference in the mean length of the eustachian tube when comparing OSMF cases with normal. However, as the disease worsened, the length on the right and left sides significantly decreased. Additionally, there was no statistically significant difference in the mean eustachian tube volume between disease cases and controls. According to the clinical subgrades, the overall volume decreased from lower grade to higher grade, but there was no discernible difference between the left and right ear. The volume on function sub-grading between the right and left ear, however, was significantly reduced. Thus, the length and volume of ET decreased as the disease severity increased, but the mild to moderate hearing loss found in different clinical and functional grades of OSMF cases was not statistically significant.  Therefore, from the present study, it can be concluded that all OSMF cases should be evaluated for hearing deficit, and imaging of the eustachian tube should be part of the OSMF assessment for morphological changes of the ET that may cause hearing deficit.