The infraorbital foramen is a small opening located in the maxilla, one of the main bones of the face. This opening serves as a passageway for several structures, playing a role in the sensory and vascular supply of the mid-face. Understanding its location and function is helpful for comprehending various conditions that might affect this region.
Location and Basic Structure
The infraorbital foramen is located on the front surface of the maxilla, just beneath the lower edge of the eye socket (orbit). It is a small hole positioned above the canine tooth and to the side of the nose. It is typically found 6.10 to 10.9 millimeters (0.24 to 0.43 inches) below the infraorbital margin, the lower rim of the eye socket. Its position can be visualized by imagining a vertical line extending downwards from the middle of the pupil, passing through the infraorbital foramen and further down to the mental foramen in the chin.
The infraorbital foramen represents the outer end of a channel called the infraorbital canal. This canal begins deeper within the skull as the infraorbital groove, which runs along the floor of the eye socket. The foramen is commonly oval, with a mean transverse diameter of 1.78 to 1.97 millimeters.
Nerves and Vessels It Houses
The infraorbital foramen houses the infraorbital nerve, infraorbital artery, and infraorbital vein. The infraorbital nerve is a branch of the maxillary nerve, part of the trigeminal nerve, which is responsible for facial sensation. It provides sensation to several mid-face areas.
The infraorbital nerve supplies sensation to the lower eyelid, side of the nose, and upper lip. It also provides sensation to the upper front teeth, gums, and the mucous membranes of the upper lip and maxillary sinus. The infraorbital artery and vein accompany the nerve, supplying blood and drainage to these facial regions. The artery originates from the maxillary artery and supplies muscles around the orbit and teeth, while the vein drains into the pterygoid venous plexus.
Conditions Affecting the Area
Various conditions can affect the infraorbital foramen and its housed structures, often causing symptoms in the mid-face. Nerve entrapment or compression is a common issue, often resulting from facial trauma, such as fractures of the maxilla or orbital floor. These injuries can compress or stretch the infraorbital nerve, leading to sensory changes. Inflammation or tumors in the surrounding area can also lead to nerve compression.
Infraorbital neuralgia is characterized by pain or discomfort in the infraorbital nerve’s distribution. Pain can be sharp, shooting, or tingling, triggered by light touch or movements like shaving. The symptoms can sometimes be mistaken for those of a maxillary sinus infection. Referred pain, originating from other areas but felt in the infraorbital region, can also occur due to the complex network of nerves in the head and neck.
Frequent sensory changes when the infraorbital nerve is affected include numbness, tingling, or altered sensation (dysesthesia) in the lower eyelid, side of the nose, upper lip, and upper teeth. The severity of these changes can vary from mild hypoesthesia to complete loss of sensation. Swelling or tenderness around the infraorbital foramen may also be present, often indicating inflammation or injury to the nerve and surrounding tissues.
Addressing Related Issues
When symptoms suggest an issue with the infraorbital foramen or its housed structures, consult a healthcare professional for proper diagnosis. Diagnosis typically involves a physical examination and a review of the patient’s medical history, including any facial trauma. Imaging studies, such as X-rays or CT scans, are often used to identify causes like facial fractures, inflammation, or tumors affecting the infraorbital canal.
Management depends on the cause and symptom severity. Pain management often involves medications like analgesics, anticonvulsants, or antidepressants. If inflammation is present, corticosteroids may be used to reduce swelling and promote nerve recovery. For cases of severe nerve entrapment or tumors, surgical intervention may be considered to relieve pressure on the nerve. Nerve blocks, involving local anesthetic injection near the infraorbital foramen, can be used for diagnosis and temporary pain relief.