What anatomical structure must be avoided during a maxillary block to prevent complications?

When performing a maxillary nerve block, it is crucial to avoid the maxillary sinus to prevent complications. The maxillary sinus is a large air-filled space located within the maxilla, and its proximity to the area where the block is administered makes it particularly important to be cautious. If the needle inadvertently enters the sinus during the procedure, it can lead to complications such as sinusitis, hemorrhage, or the introduction of infection.

The anatomy of the maxillary region indicates that the sinus is often at risk during the administration of local anesthesia due to its position above the roots of the upper molars and premolars. Ensuring that the needle is directed appropriately and that the anesthesia is administered at the correct depth helps mitigate the risk of penetrating this sinus.

While other anatomical structures, such as the orbital floor, zygomatic arch, or nasal cavity, are also nearby and warrant caution during the procedure, avoiding the maxillary sinus is particularly critical to prevent significant complications associated with its injury.