European Journal of Anatomy

Official Journal of The Spanish Society of Anatomy
Cover Volume 11 - Number 1
Eur J Anat, 11 (1): 1-7 (2007)

The asymmetry index of the cricoid cartilage and the external angle of the thyroid cartilage. A sex-related study

Pereira Jotz G., Zaquia Leao H., Pereira Da Costa Filho O., Fisch P., Coelho Magalhaes R., Cervantes O.

Department of Otolaryngology-Head and Neck Surgery, Lutheran University of Brazil; Department of Morphological Sciences, Federal University of Rio Grande do Sul, RS, Brazil; Department of Morphological Sciences, Lutheran University of Brazil, RS, Brazil; Lutheran University of Brazil, RS, Brazil; Otolaryngology, Head and Neck Surgery Department, Federal University of São Paulo, São Paulo, SP, Brazil; Dept. of Morphological Sciences, Federal University of Rio Grande do Sul, Rua Dom Pedro II 891 / 604, Porto Alegre, RS. Cep 90550-142, Brazil

ABSTRACT The aim of the study was to assess whether the transverse diameter is directly proportional, and the anterior-posterior diameter inversely proportional, to the angle of the thyroid cartilage, thus determining the degree of asymmetry in relation to age and sex, by comparing specimens of larynxes. Analyses were performed on specimens of larynxes from cadavers: 50 male and 50 female. The age range varied from 40 to 98 years, with an average of 58.68. Macroscopic analysis for the presence of lesions was performed with the aid of a magnifying glass. A goniometer (Carci®) was used to obtain the angle of aperture of the two laminas of the thyroid cartilage. The internal dimensions of the cricoid cartilage were obtained using a digital pachymeter (Starrett® Tolls). The asymmetry index of the antero-posterior and transverse measurements of the cricoid cartilage was obtained for both sex groups. The correlation between the angle of the thyroid cartilage and degree of asymmetry of the cricoid cartilage was insignificant in both males (r=0.027; p=0.426) and females (r=0.010; p=0.472). These findings suggest that there is no relationship between the angle of the thyroid cartilage and the degree of asymmetry of the cricoid cartilage. However, a significant difference was observed between the sexes in the transverse and antero-posterior diameters of the cricoid cartilage. Contrary to expectations, the findings failed to show the suggested relationship between the asymmetry index of the internal diameters of the cricoid cartilage and the external angle of the thyroid cartilage.

Keywords: adult, aged, article, cadaver, correlation analysis, cricoid, female, goniometry, human, human tissue, larynx cartilage, male, morphometrics, normal human, sex difference

European Journal of anatomy
ISSN 2340-311X (Online)