diamond-shaped bone below and lateral to the orbit, or eye socket, at the widest part of the cheek. It adjoins the frontal bone at the outer edge of the orbit and the sphenoid and maxilla within the orbit. It forms the central part of the zygomatic arch by its attachments to the maxilla in front and to the zygomatic process of the temporal bone at the side. The zygomatic bone forms in membrane (i.e., without a cartilaginous precursor) and is ossified at birth.