ABSTRACT
The term pure orbital blowout fracture is used to describe a fracture of the orbital floor, the medial orbital wall or both, with an intact bony orbital margin. The term impure orbital blowout fracture is used when such fractures occur in conjunction with a fracture of the orbital rim e.g. as part of a zygomatic complex fracture. The most common site for a blowout fracture to occur is in the posteromedial aspect of the orbital floor, medial to the infraorbital neurovascular bundle where the maxillary bone is very thin. As the lamina papyracea is also very thin, the medial orbital wall is also prone to fracture.
