3D Modelling and Evaluation of the Morphology of Hyoid Bone

Abstract

The hyoid bone, a small U-shaped bone in the upper neck above the thyroid cartilage is a unique structure in humans as it has no bony articulation. The lack of data on morphology and position of hyoid bone is due to a large extent to difficulty in visualizing the hyoid bone using conventional radiographic techniques. Lateral cephalometry has significant limitations such as superimposition of structures, difficulty in identifying landmarks and poor visualization of structures. The aim of this study is to compare morphological and positional variations of the hyoid bone in patients who had undergone CT scans. CT scan images are modeled in MIMICS and using anthropometric analysis module, several measurements of hyoids are obtained. Hyoid bone angle was measured from the most superior medial point on the surface of the body to the base of the skull. 3D visualization of hyoid bone helps to locate the most inferior point of the anterior aspect of the foramen magnum in the mid-sagittal plane (basion) and the most inferior point of the spheno-occipital synchondrosis (SOS) on the sphenoid bone. Data collected using 3D images are used to compare the position of the hyoid bone and epiglottis in relation to the cervical vertebrae and cranial base.