For maxillary incisor anesthesia via infiltration, where is the injection placed?

For maxillary incisor anesthesia via infiltration, where is the injection placed?

• A. Mucobuccal fold apical at the tooth being anesthetized
• B. Near the mental foramen
• C. Palatal mucosa adjacent to the incisor
• D. Buccal vestibule far from the tooth

Answer: (A)

Infiltration anesthesia for a maxillary incisor is delivered by placing the needle in the mucobuccal fold right over the tooth’s apex. This location is ideal because the anesthetic is deposited directly next to the nerve entry to the tooth, and the maxillary bone is thin and porous enough for the solution to diffuse through the cancellous bone to the pulp. That diffusion numbs the tooth itself as well as the surrounding soft tissues. Injecting into the palatal mucosa would mainly numb the palate, not the incisor’s pulp. The mental foramen is a mandibular structure and relates to a different nerve supply, so it won’t reliably anesthetize a maxillary incisor. Injecting in the buccal vestibule far from the tooth won’t place anesthesia near the tooth’s nerve, so pulpal anesthesia wouldn’t be achieved.

Infiltration anesthesia for a maxillary incisor is delivered by placing the needle in the mucobuccal fold right over the tooth’s apex. This location is ideal because the anesthetic is deposited directly next to the nerve entry to the tooth, and the maxillary bone is thin and porous enough for the solution to diffuse through the cancellous bone to the pulp. That diffusion numbs the tooth itself as well as the surrounding soft tissues.

Injecting into the palatal mucosa would mainly numb the palate, not the incisor’s pulp. The mental foramen is a mandibular structure and relates to a different nerve supply, so it won’t reliably anesthetize a maxillary incisor. Injecting in the buccal vestibule far from the tooth won’t place anesthesia near the tooth’s nerve, so pulpal anesthesia wouldn’t be achieved.