Facial folds / lines

Folds are formed by facial expressions, like deep wrinkles. The
difference is that whereas wrinkles usually present as a series of
contraction lines, a fold is usually a deepening of a single facial line
where the expression occurs. The naso-labial folds (which run from the
nose to the sides of the mouth) are the most common example. 
 
Whereas many wrinkles can be relaxed with botulinum toxin injections
such as Botox™, folds are sometimes in areas which can’t be relaxed
in this way. Instead, filler injections, such as Juvederm™, Restylane™
or collagen must be used to plump the skin under the line and soften
its appearance.
 
Your skincare routine for expressive folds should focus on preserving
the skin’s collagen structures. Intact collagen provides an even base
for the upper layers of the skin. Daily use of an SPF 25+ sunscreen
protects collagen against UV-induced degradation, while vitamin C and
retinaldehyde can stimulate collagen producing cells to produce more
collagen.