Which facial bone is quadrilateral in shape and has four processes including frontosphenoidal and orbital?

• A. Zygoma/malar
• B. Nasal bone
• C. Maxilla
• D. Mandible

Answer: (A)

The facial bone that is quadrilateral in shape and possesses four processes, including the frontosphenoidal and orbital processes, is the zygoma, also known as the malar bone. This bone contributes to the prominence of the cheek and forms part of the eye socket.

The zygoma's four processes include the maxillary process (which connects to the maxilla), the frontal process (which connects to the frontal bone), the temporal process (which connects to the temporal bone), and the orbital process (which connects to the orbital cavity). The specific mention of the frontosphenoidal process highlights its connection to the frontal and sphenoid bones, further confirming the zygoma's anatomy.

In contrast, other facial bones such as the nasal bone, maxilla, and mandible have different shapes and processes, which do not fit the description provided in the question. The nasal bones are small and narrow, the maxilla is a larger bone that has different characteristics and serves distinct functions, and the mandible is the lower jawbone known for its U-shape, distinct from the quadrilateral shape of the zygoma. Thus, the detailed anatomy and features of the zygomatic bone align perfectly with the characteristics outlined in the question.