What bone forms the upper part of the jaw?

The maxilla forms the upper part of the jaw, making it the correct choice. This bone plays a crucial role in the structure of the face by holding the upper teeth and forming part of the eye sockets, nasal cavity, and the roof of the mouth (palate). It connects with several other bones in the skull, contributing to the overall architecture and function of the facial structure.

In contrast, the mandible is the lower jawbone and is responsible for the movement of chewing and speaking but does not form the upper jaw. The zygomatic bone, also known as the cheekbone, contributes to the prominence of the cheeks and forms part of the eye socket but is not part of the jaw structure. The palatine bone is located at the back of the nasal cavity and helps form the hard palate, but it does not play a role in the overall structure of the upper jaw. Thus, the maxilla is specifically the bone that fulfills the role of forming the upper part of the jaw.