Which nerve is the primary source of innervation for the oral cavity?

The trigeminal nerve is the primary source of innervation for the oral cavity because it is the main sensory nerve of the face and has a critical role in the innervation of the oral region. This nerve has three major branches: the ophthalmic, maxillary, and mandibular nerves. The maxillary and mandibular branches specifically provide sensory innervation to areas such as the upper and lower jaws, gums, lips, and the overall mucosa of the oral cavity.

In addition to sensory functions, the mandibular branch of the trigeminal nerve also supplies motor functions to the muscles of mastication, which are important for chewing. This extensive distribution and dual functionality make the trigeminal nerve vital for both sensation and function within the oral cavity.

While the facial nerve contributes to the anterior two-thirds of the tongue's taste sensation and the glossopharyngeal nerve plays a role in taste and sensory innervation to the posterior one-third of the tongue and oropharynx, neither has the same broad reach in terms of sensory and motor innervation to the oral cavity as the trigeminal nerve. The hypoglossal nerve primarily controls the movements of the tongue, which further highlights that it does not provide sensory input to