ANATOMY

Detailed explanation-1: -The depressor labii inferioris is a short quadrangular muscle found in the chin region. It originates from the oblique line of mandible while being continuous with the labial part of the platysma. The muscle courses superomedially to insert on the skin and submucosa of the lower lip.

Detailed explanation-2: -10. Depressor Anguli Oris. This muscle lowers the corners of our mouths into a frown.

Detailed explanation-3: -The lateral pterygoid muscle functions as the sole muscle of mastication to causes depression of the mandible.

Detailed explanation-4: -The lateral pterygoid muscle depresses the mandible and opens the mouth when assisted by the anterior belly of the digastric muscle and the mylohyoid muscle.

Detailed explanation-5: -The platysma is responsible for drawing the skin around the lower part of your mouth down or out, which creases the skin in your lower face, according to the Loyola University Medical Education Network.