Table 3

Ultrasound-guided maxillary nerve block approaches and strengths and weaknesses

Needle approach	Strengths	Weaknesses
Posterior infrazygomatic, in plane1 3	PPF is not directly entered, minimizing risk of maxillary artery puncture No bone contact required Needle is visualized during entire procedure Facial nerve, transverse facial artery, maxillary artery usually identifiable	Facial nerve, parotid gland in close proximity Requires mouth opening to decrease coronoid process shadow
Anterior infrazygomatic, in plane6	Decreased risk of facial nerve or parotid gland injury Coronoid process excluded by opening mouth	Requires bone contact Requires very acute angle of insonation, causing difficulty visualizing entire needle path Needle placed directly into PPF, placing maxillary artery at risk
Suprazygomatic, out of plane4 7 10	Needle directed caudal to maxillary artery	Out-of-plane approach Needle cannot be evaluated at the entry point; can only be seen after it passes beneath zygoma Requires bone contact May be affecting superficial maxillary nerve (distal)