Which cranial nerves are assessed when examining the mouth for symmetry and structure?

The correct cranial nerves to assess mouth symmetry and structure are primarily cranial nerves V (trigeminal nerve) and VII (facial nerve). When examining the mouth, it is essential to evaluate the muscle movements of the lips and cheeks, which are innervated by the facial nerve. This nerve controls expressions and movements, so any asymmetry can indicate dysfunction.

Additionally, the trigeminal nerve plays a role in sensory innervation to the oral cavity, including the gums and mucous membranes. Impairment in this nerve can alter sensory perception, affecting the assessment of symmetry.

In this context, cranial nerves IX (glossopharyngeal) and X (vagus) are involved mainly in the swallowing reflex and controlling the muscles of the pharynx and soft palate, rather than the direct examination of the mouth's structural symmetry. While they do contribute to oral functions, they are not primarily assessed through the visual inspection and motor function checks typically done for symmetry and structure in the mouth.

Thus, the focus on cranial nerve V and VII is what makes it the correct answer when examining the mouth for symmetry and structure.