RESEARCH.
LEVATOR LABII SUPERIORIS.
The major use of the Levator Labii Superioris is to lift the upper lip
into a sneer. As a secondary motion it also curls up the nose and
wrinkles the eye area. The muscle has three branches.
( see fig 12 ) All three branches come together and attach
at the same spot: the circular muscle surrounding the lips, right below
the wing of the nose. When the act of sneering is commenced it is
possible to feel the point where all three parts of the muscle attach,
and the sharp crease that appears when they contract. After they
leave their shared attachment, the three branches separate as they travel
upward to their respective bony origins. One branch travels almost
straight up alongside the nose. The middle branch attaches to the
bone of the upper jaw, just below the eye socket. The outer branch
usually referred to as the Zygomatic Minor, is fixed
to the cheekbone at it's widest spot.
A sneer only affects the upper lip, leaving the lower just the same. (
see fig 13 ) The upper lip becomes
flattened, pushed back and widened. The lip becomes more even in
width and drops straight down to it's corners, rather than tapering.
As the upper lip curls upward, it lifts slightly off the lower lip.
The lift is strongest in the outer ends, and here the gap between the lips
widens. A sneer on only one side of the lip is possible. The
other side remains relaxed.
Fig 12 - The Levator Labii Superioris Muscle Fibers.
Fig 13 - The Levator Labii Superioris in
action.