Which structure is a U-shaped bone in the neck that can serve as a radiographic reference?

• A. Mandible
• B. Hyoid bone
• C. Airway
• D. Cervical spine

Answer: (B)

The main idea is that certain skeletal landmarks provide stable references for labeling and aligning head and neck images. The hyoid bone is a horseshoe- or U-shaped bone located in the front of the neck, suspended by ligaments and muscles and not forming joints with other bones. Its distinct U-shape and relatively fixed position near the level of the C3 vertebra make it easily identifiable on radiographs and a useful reference point for head/neck orientation and airway assessment. The mandible is the jawbone in the lower face, not a neck landmark; the airway is soft tissue and not a bone; and the cervical spine is a series of vertebrae, not a single U-shaped structure.