Characteristics of Sonotubometry According to Eustachian Tube Disorder

Background and Objectives: When the eustachian tube fails to open properly, leading to inadequate ventilation or difficulty equalizing external pressure, it is diagnosed as dilatory eustachian tube dysfunction. If the E-tube remains open without proper closure after opening, it is classified as patulous eustachian tube dysfunction. This study aims to classify groups based on Eustachian tube (E-tube) opening and closure states, analyze sonotubometry characteristics within each group, and provide foundational data for E-tube function testing. Materials and Methods: This study analyzed 752 ears from who underwent sonotubometry, categorized into three groups: Normal 147 ears, patulous eustachian tube dysfunction (PET) 81 ears, and dilatory eustachian tube dysfunction (ETD) 41 ears. E-tube opening duration time and changes in sound magnitude were compared among the groups. receiver operating characteristics (ROC) analysis was performed to determine cut-off values for differentiating ETD from Normal based on E-tube opening and closure status. Results: The ETD group had significantly shorter E-tube opening duration time compared to both the Normal and PET groups. Conversely, the PET group had significantly longer opening duration time than the Normal group. Additionally, the ETD group showed significantly smaller changes in sound magnitude compared to the other groups, while the PET group had significantly larger changes compared to the Normal group. Cut-off values for normal E-tube function were 242.50 ms for opening duration time and 6.435 dB for changes in sound magnitude. Conclusion: Sonotubometry is highly sensitive and specific for assessing normal E-tube function and diagnosing PET and ETD, making it essential for evaluating E-tube disorders.