Ultrasound-Guided Suprazygomatic Maxillary Nerve Block for Cleft Lip Repair in Pediatric Patients

After induction of anesthesia and securing the airway, the child’s head is positioned neutrally. The junction of the lateral orbital rim and the superior border of the zygomatic arch is marked as the needle insertion point. The needle is inserted perpendicularly until it contacts the greater wing of the sphenoid at a depth of approximately 15–20 mm, then redirected anteromedially toward the contralateral tragus and advanced to a depth of 35–45 mm to access the pterygopalatine fossa (PPF). Under ultrasound guidance, a high-frequency probe is placed in the infrazygomatic region at a 45° angle in both axial and coronal planes to identify the boundaries of the PPF and visualize the internal maxillary artery. An out-of-plane approach is used to confirm needle placement and observe the spread of local anesthetic. Following negative aspiration, 0.1 mL/kg (maximum 5 mL) of local anesthetic is injected slowly.

The SZMN block provides effective perioperative analgesia for surgeries involving the midface, including cleft palate repair, maxillary osteotomies, and FESS. This case demonstrates the performance of a bilateral block using a combined landmark and ultrasound-guided approach to optimize precision and safety. Although commonly performed for cleft palate repair, maxillary nerve blocks are also indicated for maxillary osteotomies and functional endoscopic sinus surgeries (FESS). Approaches to the maxillary nerve include the technically challenging intraoral approach, which is less preferred in pediatric patients, and extraoral approaches, such as the infrazygomatic and suprazygomatic techniques. The suprazygomatic approach is favored for its relative safety and ease of execution.

Contraindications are similar to those for other peripheral nerve blocks and include patient or parent refusal, allergy to local anesthetics, active infection at the injection site, coagulopathy or use of antithrombotic medications, and pre-existing neural deficits in the distribution of the block.

High-frequency linear ultrasound probe

22–25 gauge hyperechoic nerve block needle (50 mm)

5 mL syringe

Syringe with normal saline for hydrodissection

ChloraPrep sticks

Sterile gloves and ultrasound probe cover

Ropivacaine 0.2% or bupivacaine 0.25%

After induction of anesthesia and securing the airway, the child’s head is positioned neutrally.

Preoperative workup includes evaluation for risk of anesthesia and surgery.

The suprazygomatic maxillary nerve (SZMN) block targets the maxillary nerve, located within the pterygopalatine fossa. This nerve, the second division of the trigeminal nerve (V2), is purely sensory and provides sensation to the midface, including the palate. The maxillary nerve exits the middle cranial fossa through the foramen rotundum, traverses the pterygopalatine fossa—a cone-shaped space between the infratemporal fossa and the nasopharynx—and gives off multiple sensory branches.

The pterygopalatine fossa is bounded by the maxilla, palatine, and sphenoid bones and contains critical neurovascular structures, including the maxillary nerve, the maxillary artery, and the pterygopalatine ganglion—a parasympathetic ganglion located just inferior to the maxillary nerve, connected by short ganglionic branches. The goal of the block is to deposit local anesthetic near the maxillary nerve and pterygopalatine ganglion to achieve effective sensory blockade of the midfacial region.

Complications, though uncommon, may include bleeding, infection, and cranial nerve palsies (such as abducens or oculomotor nerve palsy). Ultrasound guidance significantly improves procedural safety by allowing precise visualization of anatomy and local anesthetic spread.

None declared.

Mesnil M, Dadure C, Captier G, et al. A new approach for peri-operative analgesia of cleft palate repair in infants: the bilateral suprazygomatic maxillary nerve block. Paediatric Anaesthesia. 2010;20(4):343-349. doi:10.1111/j.1460-9592.2010.03262.x.

Echaniz G, Chan V, Maynes JT, Jozaghi Y, Agur A. Ultrasound-guided maxillary nerve block: an anatomical study using the suprazygomatic approach. Canadian Journal of Anesthesia. 2020;67(2):186-193. doi:10.1007/s12630-019-01481-x.

Fell M, Fenner L, Fallico N. Demystifying the suprazygomatic maxillary nerve block in paediatric cleft palate surgery. Cleft Palate–Craniofacial Journal. Published online September 10, 2024. doi:10.1177/10556656241284514.