Location of the infraorbital foramen with reference to soft tissue landmarks for regional nerve blocks during midface surgery

Abstract

Purpose: An infraorbital nerve (ION) block is widely used to accomplish regional anesthesia during surgical procedures involving the midface region. This study aimed to elucidate the exact location of the infraorbital foramen (IOF) in relation to clinically useful soft-tissue landmarks for achieving an effective ION block. Methods: Forty-three hemifaces from 23 embalmed Korean cadavers were dissected. The lateral canthus, peak of Cupid's bow, medial limbus, and midline were used as reference points. The distances from the IOF to the midline and the lateral canthus were measured. Results: The IOF was located approximately 25 mm below the lateral canthus and 27 mm lateral to the midline. In all cases, the IOF was situated within 9.0 mm of the crossing point of the oblique line connecting the lateral canthus to the peak of Cupid's bow and the vertical line through the medial limbus. Conclusion: Considering the spread of an anesthetic agent, injecting it into the crossing point of the oblique line through the lateral canthus to the peak of Cupid's bow and the vertical line through the medial limbus would successfully block the ION in most patients.

Three-point Method Nerve Block for Relieving Pain of Microbotox Injection in Middle and Upper Face

“… 7 Their cranial exit positions and nerve emergence routes vary greatly between individuals, and clinical localization methods are diverse. 8 , 9 , 17 Anatomical variations also bring challenges to surgical operations; for instance, maxillofacial doctors have found an accessory infraorbital foramen on the medial side of the infraorbital foramen, with a probability of approximately 18.2% or even higher, and the accessory branch of the infraorbital nerve mostly provides sensory innervation to the lower eyelid and nasal dorsum. The presence of the accessory infraorbital foramen may lead to the failure of the infraorbital nerve block.…”

“…4,5 In the traditional nerve block technique, anesthetics are injected into the peripheral nerve trunk at a single point to anesthetize the area innervated by the nerve by blocking the conduction of nerve impulses, thereby avoiding the swelling and deformation caused by local anesthesia and reducing the amount of anesthetic. [6][7][8] However, owing to the large variation in cranial exit points, if the injection point is inaccurate, the blocking effect will be greatly reduced, and it is often accompanied by anesthesia of uninvolved areas. [8][9][10][11] Therefore, based on the ultrasonic measurement of the anatomical position of the supraorbital and infraorbital foramens, combined with abundant experience of botulinum toxin injection in the face, we propose a new threepoint method for precise middle and upper facial nerve block.…”

“…[6][7][8] However, owing to the large variation in cranial exit points, if the injection point is inaccurate, the blocking effect will be greatly reduced, and it is often accompanied by anesthesia of uninvolved areas. [8][9][10][11] Therefore, based on the ultrasonic measurement of the anatomical position of the supraorbital and infraorbital foramens, combined with abundant experience of botulinum toxin injection in the face, we propose a new threepoint method for precise middle and upper facial nerve block. This technique combines the nerve block effect with the local infiltration anesthesia effect, exerting an analgesic effect through linear injection of a small amount of anesthetic agent on the initial location of sensory nerve branch in the injection area.…”

“…4,5 In the traditional nerve block technique, anesthetics are injected into the peripheral nerve trunk at a single point to anesthetize the area innervated by the nerve by blocking the conduction of nerve impulses, thereby avoiding the swelling and deformation caused by local anesthesia and reducing the amount of anesthetic. 6–8 However, owing to the large variation in cranial exit points, if the injection point is inaccurate, the blocking effect will be greatly reduced, and it is often accompanied by anesthesia of uninvolved areas. 8–11…”

“False” foramina and fissures of the skull: a narrative review with clinical implications

“…It is an important landmark for endonasal endoscopic and orbital surgeries [10,40]. The fissure ends at the infraorbital foramen on the face [42].…”