Dimensions of the laryngeal framework in adults

The increasing application of sophisticated electrophysiological, radiological and surgical methods to the diagnosis and treatment of laryngeal disorders requires a profound knowledge of the size and proportions of the human larynx and it's cartilaginous components. Only inadequate data regarding this subject have so far been accessible. The larynges of 53 patients (28 male and 25 female, age 25-88 years, in the means 59 years) were removed during routine autopsy 12-48 h post mortem and immediately submitted to morphometric investigation. None of the patients had histories or visible signs of laryngeal disease. Anatomical preparations were performed with customary surgical tools and morphometric measurements then carried out with a pair of compasses and a calliper rule. A total of 95 measurements were performed on each larynx. These included, aside from evaluation of the whole organ, identification of the internal and external diameters of the cricoid cartilage, height and length of the thyroid alae in different planes, angle of thyroid laminae, height of arytenoid cartilage, width and length of epiglottic cartilage, and internal and external diameter of first tracheal ring. The results obtained provide a full scale of data determining the size and extent not only of it's cartilaginous components, but of the laryngeal framework as a whole. The knowledge of these data may contribute to a precise positioning of electrodes in laryngeal electromyography, to the planning of laryngeal framework surgery, and to the analysis of CT- and MRI-scans of the larynx.