RESEARCH.
FRONTALIS.
The Frontalis lifts the eyebrows straight up the forehead, creating a small
network of wrinkles that we mainly identify as 'worry lines.' (see
fig .06) It contributes to the expression of surprise, fear
and sadness. It is a broad, flat muscle that lies across the entire
width of the forehead. (see fig .07)
It's muscle fibers run vertically, dropping from the hairline, where they
are held in place, to it's unconnected end, the skin underneath the eyebrows.
When the frontalis contracts, all the skin just above the eyes and nose
is pulled straight up towards the hairline, with eyebrows pulled up also.
As the forehead rises, the skin caught in the way gathers into horizontal
creases. Some people exhibit no crease lines. Others have maybe
half a dozen or more, fairly evenly spaced, but the creases will never
exactly be straight. Typically, they will have a long dip in the
middle, as they near the side of the forehead, they will suddenly change
direction, curve sharply downward and die out. When the lift of the
brow is only partial, fewer wrinkles, and fewer complete ones, will appear.
Fig . 07 Frontalis - Sheet muscle.
Fig . 06 - Frontalis in action.