Which cranial nerve assists with the movement of the muscles of mastication?

The trigeminal nerve (CN V) is primarily responsible for the movement of the muscles of mastication, which are crucial for the process of chewing. This nerve has three major branches—the ophthalmic, maxillary, and mandibular branches—with the mandibular branch specifically innervating the muscles that aid in mastication, such as the masseter, temporalis, and pterygoid muscles.

These muscles work together to enable the jaw to move up and down and side to side, facilitating the grinding and tearing of food. Additionally, the sensory component of the trigeminal nerve provides sensation to the face and oral cavity, which is important for the chewing process.

Other cranial nerves listed do not play a direct role in mastication. The facial nerve (CN VII) primarily innervates the muscles of facial expression and has some taste functions. The hypoglossal nerve (CN XII) is involved in tongue movement, crucial for swallowing and speech but not chewing. The vagus nerve (CN X) has diverse functions including autonomic control of the heart and digestive tract but does not directly control chewing muscles. Hence, the trigeminal nerve’s specific role in muscle movement for chewing makes it the correct answer.