Which muscle pulls the corners of the mouth downward, also known as Triangularis?

Which muscle pulls the corners of the mouth downward, also known as Triangularis?

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

Answer: (C)

The movement described is produced by the depressor anguli oris, the triangularis. This muscle runs from the lower jaw to the angle of the mouth and contracts to pull the corners downward, creating a frown. The other muscles do different things: one lifts the corners of the mouth, another lowers the lower lip, and they don’t pull the mouth corners downward. So the action matches triangularis exactly.

The movement described is produced by the depressor anguli oris, the triangularis. This muscle runs from the lower jaw to the angle of the mouth and contracts to pull the corners downward, creating a frown. The other muscles do different things: one lifts the corners of the mouth, another lowers the lower lip, and they don’t pull the mouth corners downward. So the action matches triangularis exactly.