The infraorbital nerve is a major sensory nerve that supplies feeling to the middle third of the face, including the lower eyelid, the side of the nose, the upper lip, and parts of the cheek. It is a terminal branch of the maxillary division of the trigeminal nerve, and it exits the skull through a small opening called the infraorbital foramen, located just below the eye socket. Because of its position and the broad territory it covers, this nerve plays a central role in facial surgery, dental anesthesia, trauma management, and the diagnosis and treatment of several kinds of facial pain.
Where the Nerve Runs and What It Supplies
The infraorbital nerve begins its journey inside the skull, traveling forward along the floor of the eye socket in a bony channel called the infraorbital canal. It then emerges onto the face through the infraorbital foramen, a small hole in the maxillary bone roughly below the center of the eye. From there it fans out into four main branches: one heading up to the lower eyelid (the inferior palpebral branch), two supplying the nose (internal and external nasal branches), and one running down to the upper lip (the superior labial branch). Of these, the superior labial branch is the largest and produces the most sub-branches. The inferior palpebral branch typically splits into a medial and lateral twig in about six out of ten people. The internal nasal branch supplies the skin of the philtrum (the groove between nose and lip) and sends a small twig into the nasal vestibule and septum, while the external nasal branch covers an area between the root of the nose and the nostril wing.
1PubMed. Topographic distribution area of the infraorbital nerveIf you have ever had your upper lip go numb after a dental injection, that was almost certainly the infraorbital nerve being blocked. Its sensory territory is large enough that damage or irritation along any part of its course can produce symptoms across a wide swath of the midface.
Finding the Foramen on a Living Face
For clinicians performing nerve blocks or surgeons planning incisions, knowing exactly where the infraorbital foramen sits relative to visible landmarks is critical. A cadaver study found the foramen averages about 8 to 9 mm below the bony rim of the eye socket, with no significant difference between men and women or between the left and right sides of the face.
2PubMed. Anatomic characteristics of the infraorbital foramen: a cadaver studyIn terms of lateral position, the foramen tends to sit roughly 26 to 28 mm from the midline of the face. A useful clinical shortcut is to look straight down from the pupil: the foramen is typically in line with one of the upper premolar teeth. Different studies disagree slightly on which premolar. One study placed it most often in line with the first premolar, while another using dry skulls found it more frequently aligned with the second premolar.
3PubMed Central. Morphometric Analysis of the Infraorbital Foramen: The Clinical RelevanceA third study proposed using ratios between facial landmarks rather than fixed distances, since faces vary in size. By measuring the distance from the infraorbital foramen to the base of the nose and expressing it as a percentage of the overall distance from the chin to the nasal spine, clinicians can predict the foramen’s location more reliably across different skull sizes. The foramen sat at roughly 63% of that reference distance on average.
4PubMed Central. Localization of infraorbital foramen and accessory infraorbital foramen with reference to facial bony landmarks: predictive method and its accuracyAnatomical Variations That Complicate Clinical Work
The nerve’s bony pathway through the orbital floor is not as standardized as textbooks suggest. A cadaver dissection identified three distinct configurations. In about 40% of specimens, the nerve was fully enclosed in a bony canal throughout its course, with no groove visible on the orbital floor at all. In half the specimens, a thin, almost transparent shell of bone roofed over the nerve for part of its path before transitioning into a proper canal, creating what the researchers called a “pseudocanal.” Only about 10% showed the classic open groove that many anatomy textbooks depict.
5PubMed Central. Anatomical Study of the Intraosseous Pathway of the Infraorbital NerveThis matters in surgery. If a surgeon exploring the orbital floor expects to find the nerve lying in an open groove and it is actually sealed inside a canal, they might not see it, and inadvertently cut into it. Conversely, if the canal roof is paper-thin, instruments can punch through it easily.
Accessory Foramina
Some people have more than one infraorbital foramen. An extra opening, called an accessory infraorbital foramen, can house a separate small nerve branch. Cadaver studies have found these in roughly 15 to 37% of specimens, depending on the population studied and the method used.
6PubMed. Anatomic characteristics of the infraorbital foramen: a cadaver study7PubMed. Anatomic Study of Accessory Infraorbital Nerves and Foramina: Application for a Better Understanding of Complications of Le Fort Fractures and Osteotomy
A large CT-based study of over 500 patients put the prevalence lower, at about 7%, which may reflect the imaging method’s detection limits compared to hands-on dissection.
8PubMed Central. Accessory infraorbital foramen location using cone-beam computed tomographyAlmost all accessory foramina sit superomedially to the main opening, meaning slightly above and toward the nose. The accessory nerve branch traveling through this extra foramen often supplies the side of the nose, and in some cases it exclusively innervates the lower eyelid, taking over that job from the main nerve entirely. This has a direct practical consequence: if a surgeon blocks only the main infraorbital nerve before lower eyelid surgery and the patient still feels pain, an accessory nerve may be the culprit. Injecting a small amount of anesthetic at a point where a vertical line through the inner corner of the eye crosses an oblique line from the outer corner to the base of the nose can catch this variant branch.
9Scientific Reports. Location of the accessory infraorbital foramen with reference to external landmarks and its clinical implicationsDescent Into the Maxillary Sinus
In some individuals, the infraorbital canal dips down into the roof of the maxillary sinus rather than hugging the orbital floor tightly. This descent is more common when a particular type of air cell, called an infraorbital ethmoid cell (or Haller cell), is present on the same side. When the nerve hangs lower like this, the infraorbital foramen tends to be further from the orbital rim than usual. Surgeons performing sinus surgery need to be aware of this variant to avoid accidentally cutting or cauterizing the nerve during procedures inside the sinus.
10PubMed. Surgical anatomy and variations of the infraorbital nerveNerve Blocks and Anesthesia
Blocking the infraorbital nerve is one of the most useful regional anesthesia techniques in emergency medicine and facial surgery. A single injection near the infraorbital foramen can numb the entire upper lip, the cheek, the lateral nose, and the lower eyelid on that side, which makes it valuable for laceration repair, abscess drainage, or minor surgical procedures in those areas.
There are two main approaches to reaching the nerve. The percutaneous (through-the-skin) approach involves inserting a needle on the face just below the eye. The intraoral approach goes through the inside of the mouth, advancing a needle upward through the gum above the canine tooth. A small comparative study found that the intraoral route produced upper-lip numbness in all twelve subjects tested, while the through-the-skin route succeeded in nine out of twelve. The intraoral block also lasted longer on average, about 1.6 hours versus 0.9 hours for the percutaneous technique.
11PubMed. Comparison of intraoral and percutaneous approaches for infraorbital nerve blockBeyond emergency rooms, infraorbital nerve blocks are increasingly used alongside general anesthesia for nasal and facial cosmetic procedures. In a trial of patients undergoing rhinoseptoplasty (combined nose reshaping and septum straightening), adding bilateral infraorbital and infratrochlear nerve blocks with a long-acting local anesthetic reduced the total amount of morphine needed and shortened recovery room time compared to a placebo injection.
12PubMed. Infraorbital and infratrochlear nerve blocks combined with general anaesthesia for outpatient rhinoseptoplastyInjury From Facial Fractures
The infraorbital nerve’s path through the thin bone of the orbital floor makes it vulnerable whenever that bone breaks. Orbital floor blowout fractures and fractures of the cheekbone complex (zygomaticomaxillary complex, or ZMC fractures) are the most common culprits. Since the nerve runs through or very close to the fracture line, it can be bruised, stretched, or trapped by displaced bone fragments.
A study of 81 patients with these types of fractures found that more than half (about 52%) had persistent neurological symptoms. The most common complaint was reduced sensation (hypoesthesia), which occurred in about two-thirds of those affected, while roughly a quarter reported pain alone, and a smaller group had both. The cheek was the most frequently affected area. Encouragingly, about 65% experienced pronounced improvement over time, and roughly three-quarters said the residual symptoms did not significantly interfere with daily life. ZMC fractures produced more nerve problems than isolated orbital floor fractures, and patients who underwent surgery had more symptoms at six months than those managed without an operation, likely reflecting the severity of fractures that required surgical repair rather than surgery itself causing the damage.
13Journal of Craniofacial Surgery. Characterization of Infraorbital Nerve Sequelae After Orbital Floor or Zygomaticomaxillary Complex FracturesWhen nerve symptoms after a fracture progress to frank neuralgia, meaning sharp, shooting, or burning pain rather than just numbness, decompression surgery can help. A case series of nine patients who developed neuralgia after orbital floor fractures found subtle disruption of the infraorbital canal on CT in every case. During surgery, abnormal scar-like adhesions between the nerve and the bone were found in more than half. After the nerve was freed, all nine eventually had complete resolution of their pain, though recovery took anywhere from a single day to three months.
14PubMed Central. Infraorbital Nerve Decompression for Infraorbital Neuralgia/Causalgia following Blowout Orbital Fractures: A Case SeriesThese findings suggest that post-fracture neuralgia affecting this nerve is probably underdiagnosed. Clinicians following up on facial fractures sometimes focus on the cosmetic result and whether the eye moves properly, without asking specifically about pain or numbness in the cheek and lip.
Neuropathic Pain and Its Treatment
Outside of trauma, the infraorbital nerve can develop neuropathic pain from other causes, including herpes zoster (shingles) and idiopathic trigeminal neuralgia affecting the maxillary division. When pain is isolated to the infraorbital nerve’s territory, it tends to involve the side of the nose, the upper teeth (particularly the canine and first premolar area), and the cheek, producing electric shock-like, stabbing, or burning sensations.
Ultrasound-guided nerve blocks have emerged as both a diagnostic and therapeutic tool for these conditions. In one reported case, a patient with trigeminal neuralgia isolated to the infraorbital nerve territory, who had been resistant to medication for three years, received two ultrasound-guided injections of lidocaine and dexamethasone into the infraorbital foramen. Pain scores dropped dramatically and remained low for at least 21 months.
15PubMed Central. Management of isolated infraorbital neuralgia by ultrasound-guided infraorbital nerve block with combination of steroid and local anestheticWhen standard nerve blocks provide only short-lived relief, pulsed radiofrequency treatment is another option. This technique delivers brief, controlled bursts of radiofrequency energy to the nerve without destroying it outright, altering pain signaling while preserving normal sensation. A patient with intractable postherpetic neuralgia (nerve pain lingering after a shingles outbreak) along the infraorbital nerve territory received pulsed radiofrequency under ultrasound guidance and had sustained pain reduction for at least six months.
16PubMed Central. Ultrasound-guided infraorbital nerve pulsed radiofrequency treatment for intractable postherpetic neuralgiaA more aggressive approach, peripheral neurectomy (surgically cutting the nerve), has a long history. In settings where medications and less invasive procedures are unavailable or have failed, neurectomy can produce a pain-free period of roughly 17 to 24 months. Plugging the foramen with a small screw after cutting the nerve appears to extend that pain-free window beyond two years by preventing the nerve from regrowing through the opening.
17PubMed Central. Peripheral neurectomies: A treatment option for trigeminal neuralgia in rural practiceSurgical Repair When Sensation Is Lost
When the infraorbital nerve is severely damaged, whether from a fracture, a tumor removal, or an iatrogenic injury during sinus surgery, the resulting numbness of the midface can be surprisingly disabling. Patients describe difficulty eating because they cannot feel the upper lip, chronic drooling, a persistent sense that the face is swollen, and trouble with dental prosthetics. In these situations, microsurgical repair is sometimes possible.
Approaches range from simple decompression (freeing the nerve from surrounding scar tissue) to direct reconnection of the cut ends (primary anastomosis) or bridging a gap with a nerve graft harvested from elsewhere in the body. An early series of seven microsurgical cases reported complete return of sensation in six, suggesting that the nerve has a strong capacity for regeneration when given the opportunity.
18Journal of Oral and Maxillofacial Surgery. Microsurgical reconstruction of the infraorbital nervesThe choice of technique depends on what the surgeon finds once the nerve is exposed. A fracture that has pinched the nerve may only need the bone fragments lifted off. A stretch injury with intact nerve fibers may recover on its own once scar tissue is removed. A clean transection with a small gap can often be sutured directly. Larger gaps require a graft, typically taken from sensory nerves in the neck or leg.
19Atlas of the Oral and Maxillofacial Surgery Clinics of North America. Surgical Management of Infraorbital Nerve InjuriesDiagnosing Nerve Injury Without Surgery
One persistent challenge with infraorbital nerve injuries is that they are hard to measure objectively. A systematic review of studies on nerve injury after cheekbone fractures found that most assessments relied on subjective tests like asking patients to report where they felt numb, or testing two-point discrimination with calipers. Objective techniques such as blink reflex testing or current perception threshold measurements were rarely used.
20Frontiers in Oral Health. Evaluating infra-orbital nerve injury in zygomaticomaxillary complex fractures: a systematic review and meta-analysisImaging is improving, though. MR neurography, a specialized type of MRI optimized for visualizing nerves, can now identify the infraorbital nerve reliably without contrast dye. A study rating how well different trigeminal nerve branches could be seen on MR neurography gave the infraorbital nerve an average visibility score of 3.9 out of 5, with agreement among readers exceeding 80%. This opens the door to diagnosing entrapment, swelling, or discontinuity of the nerve before deciding whether surgery is needed.
21PubMed. Contrast-free visualization of distal trigeminal nerve segments using MR neurographyConnections With the Facial Nerve
The infraorbital nerve is a sensory nerve. It carries feeling, not motor commands. But it has physical connections with nearby motor branches of the facial nerve (the nerve that controls facial expression), and these connections are more extensive than you might expect. A whole-nerve staining study found that every single specimen examined had communication fibers between the infraorbital nerve and the buccal branch of the facial nerve, and about 29% also showed connections with the zygomatic branch.
22Muscle & Nerve. Sihler Staining Study of Anastomosis Between the Facial and Trigeminal Nerves in the Ocular Area and Its Clinical ImplicationsA cadaveric dissection study confirmed that these trunk-level connections between the infraorbital nerve and the facial nerve exist in every face, not just occasionally. The researchers suggested these links may help preserve function when one nerve is injured, essentially providing a backup route for signals. This could explain why some patients with facial nerve injuries retain more function than expected, or why sensory recovery after infraorbital nerve damage sometimes follows unpredictable patterns.
23Journal of Craniofacial Surgery. A Cadaveric Study of the Communication Patterns Between the Buccal Trunks of the Facial Nerve and the Infraorbital Nerve in the MidfaceDevelopment in Infants and Children
The infraorbital canal is not fully formed at birth. A morphometric study comparing prenatal and postnatal specimens found that all canal measurements were larger in the postnatal group, and the walls and branching pattern of the canal were better developed after birth. Bone formation within the canal walls progressed steadily through development.
24PubMed. A morphometric analysis of the immature human infraorbital canalThis has practical implications for pediatric surgery. In infants and very young children, the canal walls may be thinner and less complete than in adults, making the nerve more exposed during any orbital or maxillary procedure. Surgeons working in the pediatric craniofacial space need to account for the fact that the anatomical landmarks and bony protections they are accustomed to in adults may not yet exist in younger patients.
The Infraorbital Foramen Across Mammals
The infraorbital foramen is not just a human landmark. In other mammals, it transmits sensory fibers from the whiskers (vibrissae) to the brain, and its size varies dramatically across species. A comparative study found that primates and their close relatives (dermopterans, the flying lemurs) have smaller infraorbital foramina relative to skull size than most other mammals. The study confirmed a strong positive correlation between foramen size and whisker count across species. Interestingly, though primates have small foramina, they do not actually have fewer whiskers than expected. The reduced foramen size in primates may instead reflect a decreased reliance on whisker-based sensory input as vision became the dominant sense during primate evolution.
25Journal of Human Evolution. A comparative analysis of vibrissa count and infraorbital foramen area in primates and other mammalsIn humans, where whiskers are vestigial, the infraorbital foramen is small and serves exclusively to transmit the infraorbital nerve and its accompanying blood vessel to the midface skin. The evolutionary shrinkage of this opening tracks with the broader primate shift toward relying on sharp forward-facing vision rather than tactile whisker feedback for navigating the environment.