Which CN VII branch primarily innervates the orbicularis oris muscle?

Which CN VII branch primarily innervates the orbicularis oris muscle?

• A. Temporal
• B. Zygomatic
• C. Buccal
• D. Cervical

Answer: (C)

The muscles around the mouth, including orbicularis oris, are primarily supplied by the buccal branch of the facial nerve. This branch travels through the cheek toward the lips and provides motor fibers that enable lip closure and shaping. The other branches have different primary targets: the temporal branch goes to the forehead and around the eye, the zygomatic branch to the orbit and eyelid region, and the cervical branch to the platysma. Because orbicularis oris is a lip muscle and its main innervation comes from the buccal branch, that branch is the best fit.

The muscles around the mouth, including orbicularis oris, are primarily supplied by the buccal branch of the facial nerve. This branch travels through the cheek toward the lips and provides motor fibers that enable lip closure and shaping. The other branches have different primary targets: the temporal branch goes to the forehead and around the eye, the zygomatic branch to the orbit and eyelid region, and the cervical branch to the platysma. Because orbicularis oris is a lip muscle and its main innervation comes from the buccal branch, that branch is the best fit.