RESEARCH.
MENTALIS.
The Mentalis is the other half of the pout. It contributes to a great
number of expressions. This includes partly restrained anger and
sadness and the stifled smile. The mentalis creates the charismatic
down curved mouth by pushing the centre of the lips up. The lips
are pushed up because the skin over the chin, which is where the mentalis
inserts, is on it's way toward the base of the teeth, which is where the
muscle attaches. (see fig 17 )
When the mentalis contracts, the ball of the chin tries to move up and
under the base of the lower lip. If the push is strong enough, then
the lower lip thrusts further out than the upper lip in a pout.
The bottom lip becomes greatly intensified by the mentalis, with a sharper
shadow underneath and more sense of an overhang. (
see fig 18 ) The teamwork of mentalis and Triangularis
is what we see most often on the face. The action of the two muscles
compliments each other. The mentalis is the specialist in pushing
the lips up in the middle, and the triangularis in pulling the lips down
at the ends.
Fig . 17 - The Mentalis muscle fibers. Fig . 18 - The Mentalis in action.