What Is the Inferior Orbital Fissure?

The eyes of the human face are protected by a bony structure that surrounds each eye individually, called an orbit. These two cone-shaped openings or cavities consist of a base and four walls made up of separate bones coming together. The medial wall border of the orbit closest to the nose is slightly lower to give rise to the nose and create the familiar structural definition of the face. The inferior orbital fissure is the portion surrounding the eyes between the lateral section of the wall, closer to the ears, and the floor or base of the eye socket.

In human anatomy, a fissure is a natural division or split found in a body part. Formed by two separate bones, the inferior orbital fissure is actually a groove-like gap that allows nerves and blood vessels to supply the eye area with key signals from the brain and spinal cord, and with essential nutrients via a consistent blood flow to the area. The two bones making up the inferior orbital fissure are the sphenoid bone and the maxilla.

The sphenoid bone is a tapered bone that sits just anterior or in front of the temporal bone at the side of the face, the section commonly referred to as the temples. Its wedge-like shape with its extended, wing-like medial edges helps form the lateral or side section of the eye socket. The maxilla, or upper jaw bone, helps form the lower medial curvature of the eye orbit nearest to the nose. The inferior orbital fissure located within this area houses important parts of the nervous system such as the maxillary nerve and its branches, and climbing branches of the sphenopalatine ganglion.

Without this grooved crevice known as the inferior orbital fissure, the portion of the face surrounding the eyes would be unable to send and receive chemical and electrical messages resulting in a failure of the eyes to move appropriately and the inability for this area to process stimuli and respond accordingly. The maxillary nerve with its offshoots called the zygomatic branches, in and around the cheekbones, enters the orbit area through the inferior orbital fissure. This nerve and its branches give rise to nerve sensations in the cheeks and sides of the temples. The sphenopalatine ganglion, also referred to as the pterygopalatine ganglion, supplies nerve sensations to the palate, pharynx or neck and throat area, nasal sinuses, and the hard palate, or the roof of the mouth.