The comparative morphological evaluation of human male and female vocal folds, a cadaveric study

The age related structural changes in human vocal fold are known, but gender related differences in middle aged group are not precisely documented. This study is aimed to compare and evaluate the collagen, elastic fibre content of the lamina propria of middle aged male and female vocal folds. Cross sectional analysis of human cadaveric male and female vocal folds were performed. Haematoxylin & Eosin staining was used for the morphometric analysis and Verhoeff's & van Giesen stain for the collagen and elastic content evaluations. The collagen and elastic fibres morphology in the lamina propria, and thickness of the epithelium, the lamina propria were compared using the trinocular microscope, which was configured with image analysis software. It was observed that, there was a considerable difference in the lamina propria thickness, the female vocal cords being thinner. The content of collagen fibres were higher in the deeper and superficial lamina propria layers in both the sexes without any gender related differences. The elastic fibre content was more in the intermediate layer and better pronounced in females. The knowledge of lamina propria in middle aged group is important in understanding the pathophysiology of vocal fold and surgical procedures associated with it.