PAIN01.02 Pertinent Anatomy of Maxillary Local Anesthesia Practice Test

The muscles of mastication are innervated by the motor portion of the trigeminal nerve. Specifically, the motor root of CN V carries the efferent fibers that go to the muscles such as the masseter, temporalis, and the pterygoids, and it travels with the mandibular division (V3). This makes sense because V3 is the only division that contains motor fibers, while the other divisions (V1 and V2) are purely sensory. So the motor root, joining with V3, is the structure that supplies these muscles.