Question

All of the following are pneumatic bones except?

• A. Frontal
• B. Ethmoid
• C. Mandible
• D. Maxilla

Hint:

Pneumatic bones enclose paranasal sinuses; the mandible has no air sinus.

Answer 1

The Correct Option is C

Step 1: Define a pneumatic bone. A pneumatic bone contains an air-filled cavity (sinus) within it, which makes the bone light, aids resonance of the voice, and helps warm and humidify inspired air.
Step 2: List the pneumatic bones of the skull. The air-containing bones that enclose the paranasal sinuses are the frontal bone (frontal sinus), the ethmoid bone (ethmoidal air cells), the sphenoid bone (sphenoidal sinus), and the maxilla (maxillary sinus).
Step 3: Test each option. Frontal is pneumatic (frontal sinus). Ethmoid is pneumatic (ethmoidal air cells). Maxilla is pneumatic (maxillary sinus). The mandible does not contain an air sinus, so it is NOT a pneumatic bone.
Conclusion: The exception is the mandible, so the correct answer is option 3.