Final answer:
To numb the lower second molar for dental work, an injection to block the inferior alveolar nerve is necessary. This is done by placing the anesthesia into the lateral wall of the oral cavity prior to the nerve entering the mandibular foramen, near the lingula.
Step-by-step explanation:
The nerve that needs to be numbed for dental work on the lower second molar near the buccal shelf is associated with the mandibular foramen. The inferior alveolar nerve, which is a branch of the mandibular nerve, passes through the mandibular foramen and innervates the lower teeth. In order to effectively numb this area, a dentist must inject anesthesia into the lateral wall of the oral cavity at a precise location before this sensory nerve enters the mandibular foramen.
The location of the mandibular foramen is just behind the lingula, a small bony protrusion on the medial side of the mandible, which is important to know as a reference point for the correct placement of the anesthesia injection. The lingula serves as an anatomical landmark during the administration of anesthesia to block the inferior alveolar nerve.