Which nerve block provides soft tissue anesthesia of the lower lip and chin?

The mental nerve block provides soft tissue anesthesia of the lower lip and chin because the mental nerve is a terminal branch of the inferior alveolar nerve. It emerges from the mental foramen, typically located between the premolars in the mandible, and supplies sensory innervation to the skin of the lower lip, the chin, and the mucosa of the vestibule.

When performing a mental nerve block, the anesthetic agent is deposited near the mental nerve as it exits the mental foramen. This effectively numbs the areas supplied by the mental nerve, resulting in a loss of sensation in the lower lip and chin, which is precisely what's needed for procedures in that region.

Other options involve different areas of anesthesia. The incisive nerve block typically affects the incisive area of the mandible but does not provide soft tissue anesthesia of the lip and chin. The inferior alveolar nerve block anesthetizes the lower teeth and adjacent tissues but doesn't specifically numb the lower lip and chin unless the mental nerve is also involved. The buccal nerve primarily provides sensation to the buccal mucosa and does not cover the lower lip and chin areas. Therefore, the mental nerve block is the most accurate choice for achieving soft tissue anesthesia in the specified areas.