Facial surface

The facial surface of the maxilla (Facies facialis) is external and irregularly convex. Its caudal limit is marked by two prominences:

-the maxillar tuberosity (Tuber maxillae) is the ventral one  that bends behind the last molar tooth; -the zygomatic process (Processus zygomaticus), is the dorsal one that connects to the zygomatic bone by a broad rough surface.

Descending from the zygomatic bone, the facial crest (Crista facialis), a line of muscular insertion that varies much according to the species, ends usually on the facial tubercle (Tuber faciale).

Rostrally to the facial tubercle, The infra-orbital foramen (Foramen infraorbitale) ends the infra-orbital canal (Canalis infraorbitalis) which has crossed the maxilla from the caudal maxillary foramen (Foramen maxillare); this canal delegates an accessory branch in the thickness of the bone until the incisive region: the maxilloincisive canal (Canalis maxilloincisivus). In front of the infra-orbital foramen, the -barely visible in Equidae, but vast and deep in Porcines- canine fossa (Fossa canina) extends. In the species in which the canine tooth is well developed, this fossa is limited to the very rostral part, by the canine bump, a relief that corresponds to the alveola of this tooth. The molar teeth determine in the same way the vertical and more or less prominent alveolar reliefs (Juga alveolaria) on the ventral margin of this surface.