The maxillary nerve (CN V2) provides sensory innervation to the midface. Several types of maxillary nerve blocks can be performed, and they utilize different anatomical landmarks.

Maxillary Nerve Block via the Greater Palatine Canal:

• The puncture point is 4-5 mm anterior to the greater palatine foramen.
• The needle must pass through soft tissue before entering the foramen.
• The greater palatine foramen is located between the second and third maxillary molars, about 1 cm towards the midline of the palate from the palatal gingival margin.
• The foramen opens into the greater palatine canal, which leads to the pterygopalatine fossa.

Maxillary Nerve Block via the Pterygomaxillary Fissure (High Tuberosity Approach):

• A 25-gauge long needle is inserted high in the mucobuccal fold above the distal aspect of the maxillary second molar.
• The patient's mouth should be partially open with the mandible retracted toward the injection side.
• The needle is advanced upward, inward, and backward for approximately 30 mm.
• The needle tip should end in the pterygopalatine fossa, near the maxillary nerve.

Infraorbital Nerve Block:

• The infraorbital foramen is a key landmark, and it can be located by palpating the supraorbital and infraorbital notches.
• An imaginary vertical line can be drawn through the supraorbital notch, the pupil of the eye, and the infraorbital notch, and this line will pass through the infraorbital foramen. The mental foramen will also be on this line.
• The infraorbital foramen is located in the deepest part of the infraorbital depression, which is felt as a concavity when moving inferiorly from the infraorbital margin.
• The bicuspid teeth are also a landmark. There are three approaches:
  • Bicuspid approach: The needle is oriented parallel to the bicuspids towards the infraorbital foramen.
  • Central incisor approach: The needle bisects the central incisor from mesial to distal.
  • Extraoral approach: The needle is directed towards the infraorbital foramen, just lateral to the nasolabial fold, in a superior and mediolateral direction.

Posterior Superior Alveolar Nerve Block:

• Also called the tuberosity block.
• The patient’s maxillary occlusal plane should be at a 45-degree angle to the floor.
• The needle is inserted at the height of the mucobuccal fold in the region distal to the maxillary second molar.