What does the Mental Nerve Block not numb?

The Mental Nerve Block specifically targets the mental nerve, which primarily provides sensory innervation to the lower lip and the chin area. It does not provide sensation to the tongue because the tongue receives its sensory supply from different nerves, notably the lingual nerve, which is a branch of the mandibular nerve (V3).

In the context of the other options, the first molar, upper lip, and buccal mucosa are all areas that can be affected by the mental nerve block to some extent. The first molar receives some innervation from nearby nerves, and the upper lip and buccal mucosa are within the sensory distribution of the mental nerve. This makes the option regarding the tongue the only correct choice, as it is outside the clinical scope of what the mental nerve block numbs.