Facial Anatomy for Neuromodulators 101
Among the most important concepts to master prior to
performing neuromodulator injections is to fully understand muscle anatomy in
the region. Below are among the most commonly injected muscles on the head
and neck for cosmetic purposes:
Frontalis: This is the muscle responsible for the horizontal forehead
lines. When this muscle is injected with a neuromodulator it softens the
elevation of the forehead and brows. Too powerful of injections, especially
laterally in the forehead just above the brow, can cause drooping. So caution
must be taken to avoid over correction.
Corrugators: These muscles work together to form the infamous "11s" or
vertical lines in the glabella. Together with the procerus muscle (see
below), the corrugators contribute to the hyper-functional movement between the
brows forming vertical lines.
Depressor Supercilli: These muscles also play a key role in forming vertical
lines in the frown or glabella area.
Orbicularis Oculi: These muscles are responsible for closing the eye and
allow for squinting. This muscle forms crows feet, or the thin horizontal
lines around the eyes.
Procerus: Alongside the corrugators, this muscle lies within the
center of the glabella and is also a contributor to frowning, resulting in
horizontal lines in the glabella.
Platysma: This is the large muscle of the neck which as we age may form very
visible bands and sagging. Injection into this muscle results in a smooth
and lifted neckline.
Nasalis: This muscle is responsible for forming "bunny lines" or
horizontal lines in the glabella and along the sides of the nose.
Orbicularis Oris: This is the muscle around the mouth that may lead
to vertical lines or "lipstick" lines with chronic use or pursing of the lips.
Older patients may complain that they cannot apply lipstick without it running.
Lines caused by this muscle are typically more evident in individuals who
are/were chronic smokers.
Depressor Anguli Oris: Originating at the inferior border of
the mandible at the vertical level of the midpupillary line, this muscle
inserts onto the corner of the mouth, forming lines that may begin to angle the
mouth downward. To subtly elevate the mouth the DAOs may be injected.
It is important to note that lines form
perpendicular to the way the fibers of the muscle run. So as you review
your anatomy book this makes it much more clear where and how the lines are
formed over time. Remember, understanding facial anatomy is essential, but
just as crucial is recognizing the unique anatomy in each individual. Some
patients have very prominent muscles while others may not require as much in
certain areas to soften. No two patients' features or musculature are
identical, so certainly understand facial anatomy, but treat each patient
unique to their needs.