Orbital surface of maxilla

The orbital surface of maxilla is the superior surface of maxilla that creates the floor of the eye socket, or orbit, acting like the ground where the eye sits. It is smooth and triangular in shape.

The front border of the orbital surface helps form the infraorbital rim, marking a boundary between the orbital surface and the anterior (or facial) surface of the maxilla. This edge continues to merge with the anterior lacrimal crest of the maxilla’s frontal process.

The posterior border of this orbital surface is smooth and rounded, forming part of the front edge of the inferior orbital fissure. A distinctive characteristic is the infraorbital groove situated centrally, which advances forward on the orbital surface to become the infraorbital canal. This canal emerges on the face's front as the infraorbital foramen, facilitating the passage of the infraorbital vessels and nerve. Additionally, a branch from this canal descends into the front wall of the maxillary sinus, carrying the anterior superior alveolar vessels and nerve to the front teeth of the maxilla.

At the front part of the medial border, there is a concave section known as the lacrimal notch, which connects with the lacrimal hamulus. Moving backward from this point, the medial border of the orbital surface connects with the lacrimal bone, and further back, the maxilla’s medial border joins with the orbital surface of the ethmoid labyrinth.

Lastly, the inferior oblique muscle, one of the extraocular muscles moving the eye, originates from a depression immediately lateral to the lacrimal notch at the orbital surface’s anteromedial angle.