Morphological study of the human hyoid bone with three-dimensional CT images -Gender difference and age-related changes.

The human hyoid bone supports the base of the tongue and is involved in breathing, chewing, and swallowing as well as in the muscle movements associated with articulation. Accordingly it plays an important bone for a human to live. It is a very interesting organ also in multiple special area, including anatomy, mastication, swallowing, articulation, and also forensic medicine. In the morphological study of the human hyoid bone, there is a comparative anthropological research early in 1900, whereas the metrological research has been little reported later. We first used MDCT, and recorded each organic hyoid locus with a three-dimensional image for three-dimensional morphometry of gender differences, age-related changes, and the morphologic characters of the hyoid bone, and compared them with the results of our predecessors. By measuring the volume of the human hyoid bone, we identified gender difference at high rates, and estimated a certain level of ages based on the ossification at the junction area of the hyoid body and greater horns observed. Our results can be applied in the forensic medicine. By examining 600 cases, atypical horseshoes-shapes were found and the existence of the hyoid bone protrusion was demonstrated at high rates.