In blowout fracture radiographs, which sign reflects bone fragments in the sinus?

• A. Open bomb-bay door sign
• B. Tear drop sign
• C. Moon sign
• D. Double ring sign

Answer: (A)

The key idea is that a blowout fracture can drive bone fragments into the maxillary sinus, and one radiographic sign directly visualizes those osseous fragments within the sinus space. The open bomb-bay door sign captures this idea: the displaced orbital floor fragments line up with the sinus and create an appearance reminiscent of an open bombing bay door, clearly indicating bone pieces are present in the sinus.

This is the best clue because it shows actual bony material where it shouldn’t be, rather than just soft-tissue changes or indirect fracture effects. Other signs describe different tissue appearances or fracture patterns and do not specifically confirm bony fragments within the sinus, so they’re less directly indicative of intra-sinus bone pieces.