| Abstract: | The cricoarytenoid joints of 12 human adult male and female larynges were studied with regard to the anatomical reasons for arytenoid cartilage dislocation. The specimens were impregnated with curable polymers as a whole and then cut into 600–800 μm sections along different planes. The articulating surface at the upper border of the cricoid lamina revealed a striking extension backward and occasionally even slightly distalward. This may allow the arytenoid cartilage to glide in a posterior direction until it partially looses its contact to the cricoid facet. In physiologic conditions, the arytenoid position is balanced along a sagittal plane between the posterior cricoarytenoid ligament dorsally and the thyroarytenoid muscle ventrally. If one of these structures is damaged, i.e., by medical disease or trauma, the arytenoid cartilage may be pushed easily in the opposite direction. Arytenoid dislocation mainly in a posterior direction is described in literature as a possible complication of endotracheal intubation. Preparatory pharmacological muscle relaxation leads to paralysis of the thyroarytenoid muscle and its ventrally directed traction on the arytenoid cartilage. As the shape of the articulating surfaces, especially the peculiarities of the cricoid facet, even facilitates a dorsally directed movement of the Arytenoid cartilage, it may be easily displaced in a posterior direction during the procedure of endotracheal intubation. © 1994 Wiley-Liss, Inc. |
