Clinical and Anatomical Variation During Assessment of Maximum Glottic Angle

Introduction Quantitative measurement and analysis of glottic abduction is used to assess laryngeal function and success of interventions; however, the consistency of measurement over time has not been established. This study assesses the consistency of glottic abduction measurements across visits in healthy patients and anatomic factors impacting these measurements. Methods Review of patients with two sequential flexible stroboscopic exams over seven months from 2019–2022. Images of maximal glottic abduction were captured and uploaded into and measured with ImageJ. Cadaver heads were used to assess the impact of visualization angles on glottic measurements with a monofilament inserted into the supraglottis of each cadaver as a point of reference. Comparisons were done with a paired T‐test, T‐test, or Mann–Whitney U test as appropriate. Results Fifty‐nine patients and twenty‐six cadaveric exams were included. Absolute change in maximum glottic abduction angle (MGAA) was 6.90° (95% CI [5.36°, 8.42°]; p