Infraorbital nerve block

Local anesthetics are used as part of the anesthetic regimen to decrease the nociceptive input into the central nerve system (CNS) and therefore reduce the amount of the general anesthesia needed. Maxillary or infraorbital nerve blocks are recommended during clefts repair.

The roof of the mouth is formed by the incisive, maxillary and palatine bones. At the level of maxillary canine teeth there are two large openings – palatine fissures. The caudal aspect of the hard palate merges with the soft palate just caudal to the maxillary second molar teeth. The caudal aspect of the soft palate ends just at the tip of the epiglottis. Soft palate is formed by two mucosal surfaces, nasal and oral, respectively, and a muscular layer in-between.

The blood supply to the hard palate is provided by paired major palatine arteries. This artery emerges from the palatine canal through the major palatine foramen at the level of the distal aspect of maxillary fourth premolar tooth on each side. It courses rostrally in the palatine groove, which is located midway between the teeth and the midline of the palate. Blood vessels are accompanied with nerves which innervate the hard palate and regional soft tissues. Hard palate is innervated by the branches deriving from the maxillary branch of the trigeminal nerve (V). Blood supply to the soft palate includes small vessels only. Soft palate is innervated by branches of the trigeminal nerve (V), glossopharyngeal nerve (IX) and vagus (X).

The infraorbital nerve (a branch of the maxillary nerve) innervates the teeth and gingiva of the upper jaw and its block is applied (bilaterally) before CL repair.

The approach to the nerve is through the infraorbital foramen, which is located dorsal to the distal root of the maxillary third premolar tooth and can be palpated from the mucosal surface.