AMSA nerve block injection is targeted anterior superior alveolar nerve and middle superior alveolar nerve branches of infraorbital nerve through nutrient canals. Therefore, central to second premolar teeth of one quadrant can be anesthetized. The aim of the present study was to evaluate the efficacy of AMSA nerve block injection at an anterior and a posterior positions compared to commonly administrated site.

AMSA: Anterior middle superior alveolar

Inclusion Criteria:

• Healthy subject
• Subjects had all their maxillary teeth from second premolar of one side to the second premolar of another Neither of these teeth was non vital, nor had large restorations, prosthetic crowns, caries, periodontal disease, history of trauma, and hypersensitivity.

Exclusion Criteria:

• Use medications alleviating or altering the pain sensation
• Allergy to anesthetics Pregnancy