Measurement of Cross-Sectional Dimensions of the Cricoid Cartilage: A Computed Tomographic Study

Objectives: We measured the cross-sectional dimensions of the cricoid cartilage and degrees of ossification of the marrow space for designing a cricoid implant. Methods: We reviewed 100 age- and sex-matched neck computed tomography scans that were performed at Seoul National University Hospital from 2001 to 2005. Under a standardized computed tomography window setting, the height of the cricoid cartilage marrow and the thickness of the marrow space and the ossified inner and outer cortices were measured by one observer. Results: The mean height of the cricoid cartilage marrow was 13.6 mm (range, 5.5 to 20.5 mm) in women and 17.5 mm (range, 13.0 to 24.5 mm) in men. The mean thickness of the cricoid cartilage marrow was 3.17 mm (range, 1.22 to 4.75 mm) in women and 5.13 mm (range, 3.42 to 7.60 mm) in men. We also observed that women in general have a higher density of the cricoid marrow than men; 4 women and 1 man had a markedly denser marrow space. There were individual variations in size and density of the cricoid marrow. Conclusions: Human adult cricoid cartilages have sufficient marrow space for cricoid implantation. Preoperative evaluation of the size and density of the cricoid marrow is recommended for individual application of the cricoid implant.