Australian Dental Council (ADC) Practice Test

The upper first molars are primarily supplied by the posterior superior alveolar nerve, which is a branch of the maxillary nerve (part of the trigeminal nerve). The mid superior alveolar nerve also plays a role in innervating the roots of the first molars, especially if the anastomoses between the branches exist. This dual supply from both the posterior and mid superior alveolar nerves ensures adequate sensation is provided to these teeth, which is crucial for both functionality and sensory feedback when chewing or during dental procedures.

In contrast, the inferior alveolar nerve primarily innervates the lower teeth and does not supply the upper molars. The mandibular nerve, while an important branch of the trigeminal nerve, is associated with the lower jaw and does not influence the upper first molars. The buccal nerve serves sensory functions related to the buccal mucosa and does not provide innervation to the teeth directly. Thus, the posterior and mid superior alveolar nerves are the correct sources of sensory supply to the upper first molars.