Revisiting the morphometry of cricoid cartilage and vocal folds

Abstract

Background: Rima glottidis and cricoid cartilage are important parts for laryngeal passage. However, their complex anatomical organizations give rise to occur some difficulties during intubation or surgeries. Therefore, these anatomical structures have great risk of damage during these procedures. The main aim of this study is to evaluate detailed morphometric properties of these critical parts of the larynx. Methods: In this study, 74 female and 76 male patients’, without any pathology in their laryngeal and neck regions, computed tomography images were examined, retrospectively. Anteroposterior diameter of the supraglottic region immediately above the vocal folds, anterior angle of the vocal folds, transverse diameter of the rima glottidis and anteroposterior and transverse diameters of the cricoid cartilage were measured using Osirix-Lite version 9. Results: Transverse diameter of the cricoid cartilage was found less than 1 cm, however, the transverse diameter of the rima glottidis was significantly smaller. All variables except for anterior angle of the vocal folds were higher in men than women. Conclusions: The transverse diameter of the rima glottidis was the narrowest part of the laryngeal passage. The physicians should be aware of this part of the larynx besides the cricoid cartilage during endotracheal tube administrations.