Morphometry of the larynx in horizontal sections.

PURPOSE Until recently, only few studies on laryngeal morphometry in the horizontal plane, which used unreliable techniques, have been reported. The established methods of whole-organ serial sectioning of the larynx serve the purpose of histological investigation very well. Because they cause major tissue shrinkage, these techniques are not useful for morphometry. Nevertheless, normal data of laryngeal horizontal anatomy are of great surgical and diagnostic interest. Data on endolaryngeal angles, airway lumina, and the thickness of parts of the laryngeal skeleton can be helpful in the planning of endolaryngeal surgical intervention or the transcutaneous placement of electrodes for laryngeal electromyography. The aim of this study was to establish a method for the production of whole-organ serial sections that allows for the collection of exact and reliable morphometrical data. MATERIALS AND METHODS A total of 20 fresh human cadaver larynges were investigated in this study. Nineteen measurements on three different planes were obtained in each larynx. The larynges were shock-frosted using liquid propane and nitrogen and then cut with a slicing machine. Measurements were obtained using a computer-aided analyzing system. RESULTS The collected data give an exact and extensive description of the morphometrics of laryngeal structures such as thyroid and cricoid cartilage, arytenoid cartilages, vocal cords, and endolaryngeal airways at different section levels. CONCLUSION This study is the first to provide detailed anthropometric data on whole-organ sections of the larynx following a new method. This technique of using serial sections of the investigated specimen avoids artifacts caused by tissue fixation. Thus, it may be considered being particularly suited to the conduction of anthropometric studies on human larynges.