Publication:

Morphometric analysis of human cricoid cartilage: a cadaveric study

Background Cricoid cartilage is the only complete ring that surrounds the airway completely. Although it is smaller than thyroid cartilage and does not house any important structures like the thyroid cartilage (vocal folds), it forms an important cog in the upper airway. Renewed interest in subglottic stenosis recently has underscored the importance of detailed knowledge of cricoid cartilage. This study aims to augment the meagre information available on this important part of upper airway.

Methods Study design was on morphometric analysis and the setting was at tertiary health care centre. Thirty one adult human cadaveric larynges were obtained for this study. Using an electronic vernier caliper, different morphometric parameters of all the cricoid cartilages were noted down in a predesigned proforma in standard computer office software. The data thus obtained was collated and compared with existing literature.

Results The average inner transverse diameter (F: 15.05±1.02 mm; M: 17.52±2.64 mm) is greater than the average inner antero-posterior diameter (F: 12.71±0.45 mm; M: 14.11±2.55 mm). The average height of cricoid arch was F: 6.50±0.68 mm; M: 7.69±0.63 mm and the average height of cricoid lamina was F: 18.38±0.61 mm; M: 21.17±2.31 mm.

Conclusions Inter specimen disparity was noted in the various dimensions measured in the cricoid cartilages. The average transverse diameter was greater than the average antero-posterior diameter giving the cartilage an ovoid shape in nearly all specimens. Morphometrical data of the cricoid cartilage may be very useful in endotracheal intubation, laryngeal microsurgery and laryngeal framework surgery. These parameters can be helpful in evaluation of subglottic stenosis and its surgical repair.