Morphometric Study of the Larynx: A Cadaveric Study in Sri Lanka

Introduction: Morphometric data of the larynx are important for the diagnosis and treatment of laryngeal disorders, as they provide crucial information for various medical procedures and for surgeries. These measurements are fundamental in the development of biomechanical models of larynx.  
Objectives: To describe the detailed morphometry of adult human larynx and its variations.
Methods: The study was performed on 11 larynges, from 6 male and 5 female cadavers older than 40 years, with no history of laryngeal pathology, neck trauma, or neck surgery. Specific external and internal measurements of the larynx were recorded using a digital vernier caliper with an accuracy of 0.1 mm. Data were analysed using Statistical Package for Social Sciences (SPSS) version 26.0.
Results: The mean values of external and internal dimensions of the larynx were higher in males than of females, except for the length from the lower border of thyroid cartilage to the upper border of cricoid cartilage (L6) and the length of the sinus. The difference was statistically significant only for the length from floor of thyroid notch to lower border of cricoid cartilage (L3), width of thyroid cartilage (L7), length from floor of thyroid notch to projection of anterior commissure (L8) and length of infraglottic cavity. Although, bilateral asymmetry was present in majority of specimens, there was no statistically significant difference between measurements on left and right sides of bilateral structures (vestibular, vocal, and aryepiglottic folds).
Conclusion: There was a wide individual variation in both external and internal dimensions of the larynx, with males having generally higher values compared to females. This knowledge can be integrated on laryngeal morphometry into clinical and surgical practices, as well as into the design of advanced biomechanical models to achieve better patient care and innovative treatment solutions.