Which muscle lies below the levator Labii Superioris and raises the corner of the mouth?

• A. Depressor Labii Inferioris
• B. Procerus Muscle
• C. Levator Anguli Oris
• D. Nasalis

Answer: (C)

Raising the corner of the mouth is done by a small facial muscle that sits just below the levator labii superioris and attaches at the angle of the mouth. When it contracts, it pulls the corner upward, producing a smiling expression. This muscle is the levator anguli oris, and it often works together with the zygomaticus muscles to lift the mouth corners. The other muscles have different roles: the depressor labii inferioris pulls the lower lip downward; the procerus lies at the root of the nose and contributes to brow/bridge wrinkling; the nasalis controls the nostrils. So the muscle that lies beneath the levator labii superioris and raises the corner of the mouth is the levator anguli oris.