Abstract
We describe the case of a 25-year-old man with pain on turning his head to either side attributable to a malformation of the hyoid bone. When the neck was turned further to the left, the greater cornu slipped over the tuberculum anterius of the processus transversus, and locked in front of the tuberculum posterius. At the same time the thyroid cartilage caused an upward movement and separated the locked greater cornu. At the moment of this separation, a clicking sound was produced. Diagnosis was established using 3-dimensional reconstruction of CT imaging. The greater cornu of the hyoid bone was noted to be elongated and malformed, and the left greater cornu was obviously blocked by the processus transversus of cervical vertebra V. Excision of both greater cornua relieved the symptoms.
