On a panoramic radiograph, which structure appears as a U-shaped (horseshoe) radiopacity in the midline below the mandible? Panoramic radiograph; the arrows indicate the hyoid bone below the inferior border of the mandible.

The hyoid bone projects as a horseshoe-shaped radiopacity, usually bilaterally below the inferior border of the mandible on a panoramic image (at about the level of C3).Other options: The mandibular canal is a radiolucent tube; the coronoid process is a triangular projection often seen near the maxillary tuberosity; the styloid process is a thin spike from the skull base.Key exam takeaway: Hyoid bone = horseshoe radiopacity below the mandible on a panoramic film.