From the latin 'maxilla' ('jaw'), the maxillar bone is the most voluminous of the facial mass.
It is an even assymetric bone, that gives implantation to the upper premolar and molar teeth and at its rostral extremity, to the canine tooth in the species in which it exists.
Completed rostrally by the incisive bone, it constitutes the essential part of the upper jaw.
Irregularly shaped, the maxillar is made of a main body (Corpus maxillae) and several extensions.
The body is spread out on the side of the face, thick and carved by the maxillar sinus and presents a facial and a nasal surface.
The extensions are variously developed according to the species; the more characteristic is the palatine process that forms the greater part of the bony palate and contributes therefore to separate the nasal cavity from the oral cavity.