Analysis of hyoid bone using 3D geometric morphometrics: an anatomical study and discussion of potential clinical implications.

The aim of this study was to obtain a quantitative anatomical description of the hyoid bone using modern 3D reconstruction tools and to discuss potential applications of the knowledge in clinical practice. The study was conducted on 88 intact hyoid bones taken from cadavers during forensic autopsies (group 1) and on 92 bones from CT scan images of living adult subjects (group 2). Three-dimensional reconstructions were created from CT scan images using Amira 5.3.3® software. An anatomical and anthropological study of hyoid bones was carried out using metric and morphological analyses. Groups 1 and 2 were compared to evaluate the influence of muscle traction on hyoid bone shape. Characteristics of the hyoid bone were highly heterogeneous and were closely linked with the sex, height, and weight of the individuals. Length and width were significantly greater in men than in women (39.08 vs. 32.50 mm, p = 0.033 and 42.29 vs. 38.61 mm, p = 0.003), whereas the angle between the greater horns was larger in females (44.09 vs. 38.78, p = 0.007). There was a significant positive correlation between the height (Pearson coefficient correlation r = 0.533, p = 0.01) and weight (r = 0.497, p = 0.01) of subjects and the length of the hyoid bone. Significant metric differences were shown between group 1 and group 2. This very reproducible methodology is important because it may lead to clinical studies in, e.g., head and neck cancer or sleep apnea. Such studies are ongoing in our research program.