Background: The increasing application of sophisticated electro-physiological & radiological methods for the diagnosis and treatment of laryngeal disorders requires an extensive knowledge of the size and proportions of the human larynx & its cartilaginous components.
Aims: The present study was done to know the morphometric features of Thyroid and Cricoid cartilages in adult males and females by CT method in South Indian population and to compare with other studies. 

Materials and Methods: The present study was done on 62 (31 Male, 31 Female) patients undergoing CT neck attending the Department of Radiology, KR
Hospital attached to Mysore Medical College & Research Institute, Mysore for a period of 1 year from Jan 2014 to Dec 2014. In the Computerized Tomography of Neck measurements of Thyroid & Cricoid cartilages were taken. The following measurements were taken for Thyroid cartilage, thyroid angle, maximum thyroid width, median antero-posterior diameter, anteroposterior length of right and left lamina. And for Cricoid cartilage antero-posterior and transverse diameter, thickness of Arch and thickness of Lamina were measured. Results: In both thyroid and cricoid cartilages the mean values of all parameters were correspondingly higher in males except for angle between thyroid laminae which was more in females. Mean thyroid angle in males was 75.43 ± 12.09 and females 89.87 ± 12.79. Mean thyroid width in males was 40.81 ± 5.98 and females 35.52 ± 4.84. Mean median anteroposterior length in males was 29.45 ± 4.57 and females 28.7 ± 4.63. Mean antero-posterior length of right lamina in males was 36.90 ± 5.12 and females 28.7 ± 4.63. Mean antero-posterior length of left lamina in males was 38.4 ± 4.17 and females 28.8 ± 4.17. Mean antero-posterior length of Cricoid cartilage in males was 27.5 ± 2.84. Mean transverse diameter in males was 27.27 ± 2.36 & females 20.89 ± 2.06. Mean thickness of arch in males was 1.96 ± 0.84 & females 1.94 ± 0.9. Mean thickness of lamina in males was 4.24 ± 1.31 & females 4.51 ± 1.18. Conclusion: These morphological differences have important clinical and surgical implications. They are critical to the accurate placement of needles and probes in laryngeal electro myography and
vocal cord injection, medialization procedures, in performing supraglottic laryngectomy, as well as precise planning of laryngeal framework surgery.