Infra-orbital is derived from infra- meaning below and orbit which refers to the eye socket.

[2] Signs and symptoms of a canine space abscess might include swelling that obliterates the nasolabial fold.

If left untreated, infections of this space will eventually spontaneously drain via the medial or lateral canthus of the eye, as this is the path of least resistance.

This can result in septic cavernous sinus thrombosis, which is a rare, but life-threatening condition.

[1] This occurs when pus (e.g. from a periapical abscess), perforates the buccal cortical plate of the maxilla above the level of attachment of the levator anguli oris muscle.