Which of the following is NOT a facial bone?

The ethmoid bone is classified as a cranial bone, not a facial bone. The facial bones are a specific group of bones that make up the structure of the face, which includes the maxilla, mandible, and nasal bones. The maxilla forms the upper jaw and part of the cheekbones, while the mandible is the lower jaw. The nasal bones are small, paired bones that form the bridge of the nose.

In contrast, the ethmoid bone is found within the skull and contributes to the formation of the nasal cavity and orbits of the eyes, but it does not directly contribute to the structure of the face itself in the same way that the other options do. By understanding that the ethmoid is part of the cranial structure, one can clearly delineate it from the other bones listed, which all serve a foundational role in the formation of the facial skeleton.