Which facial muscle is primarily used to produce a grin by retracting the corners of the mouth?

• A. Buccinator
• B. Orbicularis oculi
• C. Depressor anguli oris
• D. Zygomaticus major

Answer: (D)

Verified step by step guidance

1. Understand the function of each muscle listed: the Buccinator compresses the cheek, the Orbicularis oculi closes the eyelids, and the Depressor anguli oris pulls the corners of the mouth downward.
2. Recall that a grin involves pulling the corners of the mouth upward and laterally, which is a movement associated with smiling or grinning.
3. Identify the muscle responsible for elevating and retracting the corners of the mouth, which is the Zygomaticus major.
4. Confirm that the Zygomaticus major originates from the zygomatic bone and inserts into the corner of the mouth, allowing it to pull the mouth corners upward and outward.
5. Conclude that the Zygomaticus major is the primary muscle used to produce a grin by retracting the corners of the mouth.