What areas are anesthetized with an ASA nerve block?

• A. Pulps of central incisors to canine on injected side; lower eyelid; lateral aspect of the nose; upper lip
• B. Palatal mucosa from canine to first molar
• C. Mandibular teeth and buccal mucosa
• D. Maxillary first molar and pterygopalatine fossa

Answer: (A)

An ASA nerve block targets the anterior superior alveolar nerve, a branch of the infraorbital nerve. When you anesthetize this nerve near the infraorbital foramen, you block sensation to the maxillary anterior teeth from the central incisors to the canine on the injected side, and you also numb the overlying facial tissues served by the infraorbital nerve—specifically the lower eyelid, the lateral aspect of the nose, and the upper lip. This exact distribution is what the option lists: pulps of the central incisors through canine on the injected side plus the lower eyelid, side of the nose, and upper lip. Palatal mucosa is not covered by this block (that would be a palatal nerve block such as the greater palatine nerve), and mandibular teeth with buccal mucosa are supplied by the mandibular nerve branches, not ASA. The last option inaccurately pairs the ASA block with the pterygopalatine fossa, which isn’t a target region for this block.