An external landmark for the anterior commissure

Objective: The ability to predict the level of the true vocal cords based on external landmarks is crucial to the success of many laryngeal surgical procedures. This study examines the reliability of one such landmark on the thyroid cartilage. Methods: Twenty-four cadaver larynges were examined. A pin was placed through the landmark, best described as a small diamond shaped area of color change and surface depression along the anterior midline of each thyroid cartilage through which travels a very small unnamed artery. The endolaryngeal position of the pin was checked with a flexible nasopharyngoscope. Results: In all 24 cadavers, the pin entered the larynx at the anterior commissure, just above or at the level of the true vocal cords. Conclusions: This external landmark reliably predicts the position of the true vocal cords. It serves as a useful adjunct to existing external landmarks used to direct thyroid cartilage cuts in laryngeal procedures.