Infraorbital nerve block

Basic. The foramen is easy to feel or see on ultrasound and the injection is shallow.

The infraorbital nerve is the end branch of the maxillary nerve (V2). It runs forwards in the floor of the orbit and comes out on the face through the infraorbital foramen, about 0.5–1 cm below the lower orbital rim, in line with the pupil.

On the face it divides into branches to the lower eyelid, the side of the nose and the upper lip (the inferior palpebral, nasal and superior labial branches).

The foramen lies under levator labii superioris. In infants it sits about halfway between the corner of the mouth and the middle of the lower eyelid.

The infraorbital artery and vein leave the foramen with the nerve.

• Lower orbital rim in line with the pupil.
• The foramen is about 0.5–1 cm below the rim.
• Infants: halfway between the corner of the mouth and the middle of the lower eyelid.

• Cleft lip repair in infants (bilateral for bilateral clefts).
• Upper lip, nose and cheek surgery, including skin lesions and lacerations.
• Endoscopic sinus surgery and septorhinoplasty, as part of the analgesia plan.
• Upper front teeth and gum procedures (intraoral approach).

• Infraorbital nerve (V2): inferior palpebral, external nasal and superior labial branches
• Often the anterior superior alveolar nerve (front upper teeth)

Surface anatomy, relevant structures and landmarks

Feel the foramen below the orbital rim in line with the pupil.

Positioning

Supine. Keep a finger on the orbital rim to protect the eye.

Block technique

• Extraoral: insert the needle just below the foramen, aiming upwards towards it, until bone is touched near the opening. Do not enter the canal. Aspirate and inject.
• Intraoral (used often in children): lift the upper lip, insert the needle into the mucosa above the canine or first premolar and advance upwards, parallel to the bone, towards the finger on the foramen.
• Press on the site afterwards to reduce swelling.

Needle choice

25–27 G, 25 mm.

Neurostimulation technique

Not used.

Choice of local anaesthetic (including volume)

• Infants: 0.5–1 mL of 0.25% bupivacaine or levobupivacaine each side (keep within weight-based limits).
• Adults: 1–3 mL of 1–2% lidocaine with adrenaline, or 0.25–0.5% bupivacaine or levobupivacaine.

Show scan

OO Orbicularis oculi muscleMaxilla MaxillaLLS Levator labii superioris muscleIOF Infraorbital foramenVessels Infraorbital vessels

Positioning

Supine with the operator at the head end.

Scanning technique

• Place a small linear probe horizontally just below the lower orbital rim.
• Slide down slowly until the smooth bright line of the maxilla shows a break: the foramen.
• Colour Doppler shows the infraorbital artery.

Structures to identify

• Maxilla (bright line)
• Infraorbital foramen
• Infraorbital nerve and artery
• Levator labii superioris and orbicularis oculi

Position / ergonomics

Stand at the head of the bed.

Probe

Small linear high-frequency (hockey-stick) probe.

Settings

Superficial preset, depth 1.5–2 cm.

Depth

0.3–1 cm.

Needle size

25–27 G, 25 mm.

Needling technique

Out of plane from below, aiming at the foramen.

Optimal needle-tip position

At the opening of the foramen, outside the canal.

Drug choice

See above.

Volume

0.5–1 mL in infants; 1–3 mL in adults.

Optimal current if nerve stimulation is used

Not used.

Muscle responses acceptable

Not applicable.

Testing block success

• Numb upper lip, side of the nose and lower eyelid

Not used.

• Keep a finger on the orbital rim and never thread the needle up the canal.
• In infants, a small volume is enough: 0.5–1 mL each side.
• For cleft palate surgery the infraorbital block alone is not enough: consider a suprazygomatic maxillary block.
• Warn patients and parents about the numb lip after surgery.

• Feriani and colleagues (Cochrane, 2016) reviewed infraorbital nerve block for cleft lip repair in children. Small trials suggested better pain relief and less need for other analgesics, but the evidence was of low quality.
• Echaniz and colleagues (2019) found bilateral suprazygomatic maxillary blocks gave better analgesia than infraorbital plus palatine blocks for combined cleft lip and palate repair.
• Allam and colleagues (2018) described the ultrasound anatomy of the infraorbital foramen.

• Feriani G, Hatanaka E, Torloni MR, da Silva EM. Infraorbital nerve block for postoperative pain following cleft lip repair in children. Cochrane Database Syst Rev 2016;4:CD011131. PubMed
• Echaniz G, De Miguel M, Merritt G, et al. Bilateral suprazygomatic maxillary nerve blocks vs. infraorbital and palatine nerve blocks in cleft lip and palate repair: a double-blind, randomised study. Eur J Anaesthesiol 2019;36:40–47. PubMed
• Allam AE, Khalil AAF, Eltawab BA, Wu WT, Chang KV. Ultrasound-guided intervention for treatment of trigeminal neuralgia: an updated review of anatomy and techniques. Pain Res Manag 2018;2018:5480728. PubMed