Ülalõualuu

Ülalõualuu, also known as the maxilla, is a paired bone of the human skull that forms the upper jaw. It is located in the midline of the face, below the ethmoid bone and in front of the sphenoid bone. The maxilla is a complex bone that contributes to the formation of several facial structures, including the orbit, the nasal cavity, and the hard palate.

Each maxilla consists of a body and four processes: the alveolar, zygomatic, palatine, and frontal processes. The body is a pyramidal-shaped structure that houses the maxillary sinus, an air-filled cavity within the bone. The alveolar process is a ridge that contains the sockets for the upper teeth. The zygomatic process articulates with the zygomatic bone, forming the inferior orbital rim. The palatine process fuses with its counterpart from the opposite side to form the anterior portion of the hard palate, separating the oral and nasal cavities. The frontal process articulates with the nasal bone and contributes to the formation of the medial wall of the orbit and the lateral wall of the nasal cavity.

The maxilla plays a crucial role in mastication, speech, and facial aesthetics. It supports the upper dentition and provides an anchor for the muscles of facial expression. Fractures of the maxilla can result from trauma and can lead to significant functional and cosmetic deficits. Surgical intervention is often required to restore the integrity and function of the maxilla.