Which nerve block can numb the lower lip and chin region?

Which nerve block can numb the lower lip and chin region?

• A. Mental/Incisive Nerve Block
• B. Infraorbital Nerve Block
• C. Nasopalatine Block
• D. Posterior Superior Alveolar Block

Answer: (A)

Numbing the lower lip and chin comes from blocking the mental nerve, a terminal branch of the inferior alveolar nerve that exits the mandible at the mental foramen. This nerve provides sensory input to the skin of the lower lip, the skin over the chin, and the associated labial mucosa of the mandibular anterior region. By depositing anesthetic near the mental foramen, the mental (and often the adjacent incisive) nerve fibers are blocked, producing numbness in the lower lip and chin area. In contrast, the infraorbital block targets the midface—affecting the lower eyelid, cheek, upper lip, and maxillary anterior teeth—so it does not numb the lower lip or chin. The nasopalatine block anesthetizes the palatal aspect of the maxillary anterior teeth and the surrounding palatal tissue, not the lower lip or chin. The posterior superior alveolar block anesthetizes the maxillary molars and related tissues, again not the lower lip or chin. Therefore, the nerve block that best provides numbness to the lower lip and chin is the mental/incisive nerve block.

Numbing the lower lip and chin comes from blocking the mental nerve, a terminal branch of the inferior alveolar nerve that exits the mandible at the mental foramen. This nerve provides sensory input to the skin of the lower lip, the skin over the chin, and the associated labial mucosa of the mandibular anterior region. By depositing anesthetic near the mental foramen, the mental (and often the adjacent incisive) nerve fibers are blocked, producing numbness in the lower lip and chin area.

In contrast, the infraorbital block targets the midface—affecting the lower eyelid, cheek, upper lip, and maxillary anterior teeth—so it does not numb the lower lip or chin. The nasopalatine block anesthetizes the palatal aspect of the maxillary anterior teeth and the surrounding palatal tissue, not the lower lip or chin. The posterior superior alveolar block anesthetizes the maxillary molars and related tissues, again not the lower lip or chin. Therefore, the nerve block that best provides numbness to the lower lip and chin is the mental/incisive nerve block.