Calcification of the interclinoid and petroclinoid ligaments of sella turcica: a radiographic study of the prevalence.

OBJECTIVES: The purpose of this study was to evaluate the prevalence of calcifications of the sella turcica, in particular, calcification of the interclinoid and petroclinoid ligaments (PCL).
DESIGN: Radiographic analysis of preoperative cephalometric film images. SETTING AND SAMPLE POPULATION: Lateral cephlometric radiographs of 255 subjects presenting for orthodontic evaluation were reviewed. The number of subjects selected for this study was determined by power analysis. EXPERIMENTAL VARIABLE: Two calibrated raters reviewed cephalometric projections and scored the films using a standardized rating scale. OUTCOME MEASURE: The rating scale classified interclinoid ligaments (ICL) into one of four categories depending on the degree of calcification and PCLs as either, no calcification, partial or complete calcification.
RESULTS: Of all subjects, calcification of the ICL ranged from 39% rated as more than half calcified to 8% completely calcified. Petroclinoid analysis revealed 67% with no calcification, 23% with partial calcification and 9% completely calcified. Spearman's correlations were computed between age and the degree of calcification and between the degree of calcification for these two ligaments with a significant association between age and degree of calcification in the PCL, r = 0.185 (p = 0.003) and a significant association between the degree of calcification in the petroclinoid and ICLs, r = 0.186 (p = 0.003). In addition, chi-squared tests demonstrated statistically significant associations between the presence of calcification in the PCL to the distribution of age (p = 0.041) and between the presence of calcification in the ICL to the distribution of age (p = 0.045).
CONCLUSION: As calcification of these ligaments has suggestive associations with disease entities, their recognition as a variant of normal anatomy should be evaluated when assessing cephalometric radiographs.