maxillaries

Maxillaries, or maxillae, are a pair of irregular bones that form the upper jaw and the central part of the face. Each maxilla contributes to the floor of the orbit, the lateral wall of the nasal cavity, and the anterior part of the hard palate, and it bears the sockets for the upper teeth. The maxilla consists of a body and several processes: the frontal (orbital) process, the zygomatic process, the alveolar process, the palatine process, and a nasal process. The body contains the maxillary sinus, a pyramidal air cavity that opens into the middle nasal meatus. The alveolar process houses the dental sockets of the upper dentition.

The palatine process of the maxilla forms most of the anterior hard palate together with the horizontal plate of the palatine bone. The infraorbital foramen on the anterior surface transmits the infraorbital nerve and vessels. The maxilla also helps form the floor of the orbit and contributes to the lateral wall of the nasal cavity.

Articulations and relationships: the maxilla articulates with several neighboring bones, including the frontal bone superiorly, the zygomatic bone laterally, and the nasal, lacrimal, ethmoid, vomer, and palatine bones. Its growth and fusion are important for proper facial form and dental alignment.

Clinical relevance: maxillary fractures, cavities, and sinusitis are common clinical concerns. Embryologically, each maxilla develops from the maxillary prominence of the first pharyngeal arch, and congenital conditions such as cleft palate can result from failure of fusion between the maxillary and palatine processes.