Quantitative Analysis of the Visor-Like Vertical Motion of the Cricoarytenoid Joint in the Living Subject

SummaryObjectivesThe cricoarytenoid joint has a loose capsule and large cavity and may allow the arytenoid distanced from the cricoid cartilage. The objective was to quantify vertical motion of the arytenoid cartilage in the living subject.Study DesignThis is a prospective study.MethodsAxial computed tomography images from 35 healthy subjects and seven patients with unilateral vocal fold paralysis were collected at inspiration and phonation. The perpendicular distance from the arytenoid vocal process (VP) or muscular process (MP) to the cricoid plane was measured and analyzed.ResultsDuring phonation, the range of the vertical movement of the VP was significantly wider than that of the MP. The vertical motion varies in sides, sexes, and ages. The vertical gaps of the VP and MP between the paralyzed and contralateral sides were about 0.8 mm and 1.5 mm, respectively.ConclusionsThis study confirms a visor-like downward vertical motion of the arytenoid cartilage during phonation.