Anatomical and functional aspects of cricothyroid joint: a cadaveric study

The pivotal role in the adjustment of the pitch of the human voice is played by the cricothyroid joint. The purpose of our study was to provide data of the morphology of articular surfaces and the range of movements occurring at the cricothyroid joints and to study the ligaments associated with the latter. The cricothyroid joints of two hundred and fifty larynges obtained from fetal, neonatal, children and adult autopsied subjects were opened to study the articular surfaces. Range of maximum possible gliding and rotational movements at the cricothyroid joints was studied in forty larynges derived from another group of autopsied subjects (18 to 80 years). The articular surface of the inferior cornu of the thyroid cartilage exhibited facet more often than cricoid and the incidence of facet increased with age. Facets were round or oval shaped and bigger on the cricoid than the inferior cornu of the thyroid cartilage. Average ventro-dorsal gliding movement in males and females were 1.88±0.76 mm and 2.08±1.20 mm respectively. Average vertical gliding movement in craniocaudal direction in males and females were 1.87±0.92 mm and 1.71±1.22 mm respectively. The average permissible rotational movement was 2.27±0.71 mm in males and 2.65±0.53 mm in females. The possible lengthening of vocal folds by rotational movement was 4.08±1.24 mm in males and 3.89±1.60 mm in females. We believe that the results of this study would contribute to understanding of the mobility at the cricothyroid joint and the data provided can be of use for surgeons during laryngeal framework surgery such as cricothyroid approximation.