Age and sex-related variation in hyoid bone morphology.

Although the relationship between hyoid bone shape and fracture pattern figures prominently in forensic investigations of strangulation, few quantitative data exist on age and sex differences in hyoid morphology. An image analysis system was used to take a series of 30 measurements on digitized radiographs of 315 hyoid bones from people of known age and sex. The degree of fusion of the greater cornua to the hyoid body was also recorded. Statistical analysis of these data shows that there is a continuous distribution of hyoid bone shapes and the most bones are highly symmetrical. Based on smaller samples, previous researchers have suggested that non-fusion is more common in women than in men. In contrast, our data suggest that men and women have similar non-fusion rates. Analysis of sexual dimorphism shows that the greatest length differences are in the greater cornua. There are also significant sex differences in hyoid shape. For example, the distal ends of the greater cornua of women are significantly longer than those of men.