Laryngeal Dimorphism: A Quantitative Analysis of Thyroid and Cricoid Cartilage in Relation to Vocal Cord Length in Indian Cadavers

Background: “Laryngeal dimorphism” means structural and functional differences in the larynx between males and females, which are primarily influenced by variations in cartilage dimensions and vocal cord length of the larynx. Studying laryngeal dimorphism enhances diagnostic precision and therapeutic approaches in otolaryngology and phono-surgery. Objective: To understand laryngeal dimorphism with examination of thyroid and cricoid cartilage morphology with variations in relation to vocal cord length in adult Indian cadavers. Materials and Methods: Fifty embalmed adult laryngeal specimens (40 male, 10 female) aged 60–75 years were dissected using standard anatomical protocols. Specimens with deformities were excluded. Parameters measured included thyroid lamina height and width, internal angle, cornua distances, vocal fold length and width, cricoid diameters, and inter-arytenoid distance. Tools included a divider, scale, wire loop, and protractor. Statistical analyses involved mean, standard deviation, p-values, and linear regression. Results: Significant sexual dimorphism was observed in internal thyroid angle (p < 0.001), lamina width, and cornua distances. Males exhibited longer and wider vocal folds (p < 0.05), though the membranous/cartilaginous ratio remained consistent across sexes. Cricoid sagittal diameter and inter-arytenoid distances were significantly greater in males. Thyroid lamina height was a strong predictor of vocal fold length (p < 0.001). Conclusion: This study gives detailed morphological parameters of important laryngeal cartilages, such as thyroid cartilage and cricoid cartilage, with vocal folds, contributing to a better understanding of laryngeal anatomy with gender differences in the Indian population, with further application to surgical approaches. KEYWORDS: Laryngeal dimorphism, Thyroid cartilage, Cricoid cartilage, Vocal folds, Sexual dimorphism, Indian cadavers, Laryngology, Forensic anatomy.