Which of the following is NOT a cranial nerve relevant to dental practice?

The optic nerve, responsible for vision, is not directly relevant to dental practice. It primarily transmits visual information from the retina to the brain, which does not interact with the dental processes or structures involved in typical dental nursing duties.

In contrast, the trigeminal nerve is crucial in dental practice as it provides sensory innervation to the face, including the teeth and gums, as well as motor functions to the muscles involved in mastication. The glossopharyngeal nerve plays a role in innervating the oropharynx and contributing to the sensation of the posterior one-third of the tongue, which is important for understanding aspects of oral perception. The hypoglossal nerve's innervation of the tongue muscles is essential for oral hygiene and patient communication during dental procedures.

Thus, while the cranial nerves listed contribute significantly to various aspects of dental practice, the optic nerve does not share this relevance in a dental context.