The hyoid bone is a bone not directly connected with other bones. Rather it is surrounded by soft tissues, mandible and vertebra. These act a protector to the traumatic injury. We herein report two cases of hyoid bone fracture. A 29- year- old man was tackled during a football game. After the game, he experienced continous pain for a week while swallowing. A plain radiograph did not reveal the cause of his pain at the first examination, but CT images taken more than a week later revealed a hyoid bone injury. The 3D image shows the dislocation of a fragment of the bone. A 46- year- old man had injured his mandible in a traffic accident and thereafter experienced severe pain in his jaw and was unable to open his mouth. The fracture of his mandibular body and ramus was found by radiography. The repositioning operation of the mandibule was considered successful, but the hyoid bone fracture was not discovered at that time. After the operation, the patient complained of gradual pain upon swallowing, and a subsequent radiographic examination showed that the hyoid bone had been fractured. In both cases, it was confirmed that ordinary lateral oblique radiography should be technically modified to some extent, and CT or other images might be necessary for the detection or diagnosis of hyoid bone fracture.
