Morphology of the dens. A quantitative study.

Morphometric studies of the dens of the second cervical vertebra were performed on a sample of one hundred twenty bones from the Hamann-Todd Collection. Data were collected on the longitudinal and transverse dimensions of the dens, as well as the size of the dens relative to the centrum of C2. Relationships of dens dimensions to body size and sexual dimorphism were evaluated. In both longitudinal and transverse mean dimensions, the dens in males was slightly, but significantly larger (5-10%) than in females. The relative distributions of dens dimensions were consistently skewed toward the higher values in males and the lower values in females. Body height or weight were not significantly correlated with dens dimensions, and were therefore poor predictors of the size of the dens. Implications for screw fixation of fractures of the dens are discussed.