Introduction: Many concerns have been expressed in the past about the assessment of vocal fold positions as part of (a) pre-operative planning and (b) post-operative outcome for larynx framework... Show moreIntroduction: Many concerns have been expressed in the past about the assessment of vocal fold positions as part of (a) pre-operative planning and (b) post-operative outcome for larynx framework surgery. Presently there is no clear strategy allowing, harmed free and office-based assessment of vocal fold vertical relative positions. The Larynx Ruler (LR) is a laser based, measuring device that could meet the previously stated need. This study represents a proof of concept regarding the use of LR in assessing vocal fold height and profile. Material and methods: One fresh male human cadaver larynx was explored with the LR system through the operative channel of a gastroenterology video-endoscope. The tip of the video-endoscope was located in the laryngeal vestibule. The right crico-arytenoid joint was posteriorly disarticulated allowing anterior and posterior tilting of the arytenoid cartilage, this to create an elevation or a depression of the vocal process. Ten push-pull motions sessions were applied to the specimen. These experimentally induced motions were compared with measurements provided by the LR Results: Data provided by the LR were always in accordance with movements applied on the vocal folds. The accuracy of 0.2 mm of the LR is compatible with the envisioned applications for the larynx. Conclusions: The LR system represented a feasible technique to evaluate vocal fold’s heights and bulk in humans. A few technical limitations were identified that will require improvements before experimental use on human. Show less
