Which of the following muscles is NOT innervated by the mandibular division of the trigeminal nerve?

The buccinator muscle is primarily innervated by the facial nerve (cranial nerve VII), which is responsible for controlling the muscles of facial expression. The buccinator plays a key role in manipulating food within the oral cavity and assisting with actions such as chewing and blowing, but due to its functional role related to facial expression and its anatomical relation, it does not receive its motor supply from the mandibular division of the trigeminal nerve.

On the other hand, the anterior part of the digastric muscle, the masseter muscle, and the mylohyoid muscle are all innervated by branches of the mandibular division of the trigeminal nerve (cranial nerve V3). The anterior digastric is associated with movements of the jaw, the masseter is a major muscle of mastication, and the mylohyoid forms the floor of the mouth. Their innervation by the trigeminal nerve reflects their roles in jaw movements and mastication, which differentiates them clearly from the buccinator.