Table 4

Summary of the literature supporting the main approaches to the ultrasound-guided maxillary nerve block

Approach	Reference	Study design	N	Injectate	Key results	Limitations
Infrazygomatic, posterior to anterior, in plane	Nader et al 20151	Case report	1	4 mL bupivacaine 0.25%+4 mg dexamethasone	Successful ultrasound-guided radiofrequency ablation in PPF reporting 100% immediate pain relief lasting over 6 months	Non-sustained pain relief despite multiple PPF injections
Infrazygomatic, posterior to anterior, in plane	Nader e t al 20133	Prospective case series	15	4 mL bupivacaine 0.25%+1 mL dexamethasone	87% (13/15) achieved good or excellent immediate and sustained pain relief in the three branches of the trigeminal nerve (V1, 2, 3) No reports of local anesthetic systemic toxicity or new neurological sequelae	14 out of 15 patients required additional injections to achieve sustained pain relief
Infrazygomatic, anterior to posterior, in plane	Kampitak et al 20186	Cadaveric study	10	3 mL methylene blue dye	Dye spread in 10/10 to maxillary nerve and sphenopalatine ganglion Dye spread in 8/10 showed spread to infraorbital foramen	Did not demonstrate retrograde spread to gasserian ganglion
Suprazygomatic, out of plane	Sola et al 20124	Prospective descriptive study	25	0.15 mL/kg 0.2% ropivacaine	Low median postoperative pain scores Low technical failure rate	10/50 blocks needed two punctures to obtain bony contact with the sphenoid bone Results in acute pain pediatric population may not be generalizable to adults with chronic pain
	Chiono et al 20147	Prospective, randomized, double-blind study	60	0.15 mL/kg 0.2% ropivacaine	Reduced total consumption of morphine at 48 hours after cleft palate repair in children. No complications 3 months after surgery	Sham study (ropivacaine vs saline) Results in acute pain pediatric population may not be generalizable to adults with chronic pain
	Bouzinac et al 201410	Case report	5	5 mL 0.2% ropivacaine	Low postoperative pain scores and decreased morphine consumption in the first 24 hours	Pain scores only followed for first 24 hours Results in acute pain population may not be generalizable to adults with chronic pain