Smile lines and marionette lines: the crease is the symptom, not the cause
Published 24 September 2026 · Reviewed by Dr Sin Yong
The two lines that bother people most — the nasolabial fold running from nose to mouth corner, and the marionette line running from mouth corner toward the jaw — share a secret: they are mostly not problems of the crease itself. They are where descending midface tissue comes to rest. Treat the crease and ignore the descent, and you get the heavy, monkey-ish lower face everyone fears. Treat the cause, and the crease softens almost as a side effect.
The fold is assessed as a consequence — where is the tissue above it coming from?
Key facts
Nasolabial fold
The line from nostril to mouth corner — the landing zone of descending malar (cheek) fat
Marionette line
The line from mouth corner toward the jaw — named for a puppet's hinged mouth
Facial fat compartments
Facial fat sits in discrete compartments that age, deflate and descend independently
Midface descent
Cheek compartments losing volume and position with age — the upstream cause of both lines
Direct filling
Filler placed in the fold itself — useful in moderation, heavy-looking in excess
Structural support
Restoring cheek projection and lateral support so less tissue collapses onto the fold
DAO muscle
Depressor anguli oris — pulls mouth corners down; a contributor to marionette heaviness
Why these lines form
Rohrich and Pessa's anatomical work established that facial fat is not one sheet but a mosaic of separate compartments — and they age separately. The midface compartments deflate and slide downward and inward with the years; the nasolabial fold is quite literally where that migrating tissue folds against the fixed anatomy around the mouth. The marionette line is the same story one act later, with the added pull of the depressor anguli oris muscle dragging the mouth corners down. Neither line is primarily a 'line problem' — they are the visible creases of a structural shift happening above them.
Why filling the crease alone disappoints
Direct filler into a deep fold does something — but the physics is unforgiving. The tissue above the fold is still descending, still pressing down; filler placed only in the crease lifts the crease floor toward tissue that keeps arriving. Chase the fold with syringe after syringe and the whole zone grows heavy, blurring the border between cheek and mouth — the overfilled lower face that photographs so unkindly. Restraint here is not caution for its own sake; it is respect for where the tissue is coming from.
“The nasolabial fold is where the descending cheek lands. Filling the landing site while ignoring the descent is how faces get heavy.”
Dr Sin YongOn treating causes, not creases
Treating the cause: support first
Cause-first treatment starts higher: restoring the deflated cheek compartments and lateral support so that less tissue collapses onto the fold in the first place. Structural volumisation at the midface, lifting energy where laxity dominates, threads where a vector of reposition helps — the combination is chosen by what the assessment finds, and a modest amount of direct fold work then finishes what the structural work began. For marionette heaviness, relaxing an overactive DAO adds a subtle but real upturn to the mouth corners. The consistent principle: the crease receives the least filler of anywhere in the plan.
What honest results look like
Done cause-first, the change reads as 'rested' rather than 'done' — the shadow of the fold lightens, the mouth corners stop looking stern, and the cheek regains the gentle forward curve that photographs as youth. The fold itself does not vanish; a visible nasolabial line is present in every adult face, including twenty-year-old ones, and erasing it entirely is neither possible nor desirable. Anyone promising a creaseless lower face is promising a strange one.
Chiefly the age-related deflation and descent of the cheek's fat compartments — the folds are where that migrating tissue creases against fixed anatomy around the mouth. Muscle pull (the DAO dragging mouth corners down) and skin-quality change contribute, particularly to marionette lines.
No — and it should not try. Every adult face has some nasolabial line; erasing it entirely requires so much filler that the lower face turns heavy and unnatural. The realistic goal is a softer shadow and a rebalanced midface, not a creaseless one.
Usually proportion: adding volume in the wrong plane or place can push tissue toward the fold, deepening its shadow. It is also possible to become more critical of a zone once attention is drawn to it. A structural review maps what is actually contributing before adding anything further.
It depends on the dominant cause: structural support and careful volumisation where descent dominates, DAO relaxation where muscle pull turns the corners down, skin-quality treatment where fine crepiness is the issue — and usually a measured combination. 'Best' is what your anatomy needs, which is what assessment decides.
Rarely. Most nasolabial and marionette concerns in the thirties to fifties are managed non-surgically with structural volumisation, energy-based lifting and muscle rebalancing. Advanced laxity does exist, and an honest assessment will say when surgical consultation makes more sense than more filler.
Structural volumisation typically supports the area for many months to beyond a year; muscle-relaxant components last months; energy-based lifting builds collagen over months with periodic maintenance. Plans are usually staged rather than delivered as one large session.
Yes — that is the core of the anatomy. Restoring midface support reduces the load of tissue folding onto the nasolabial line, and the fold softens from above. It is routinely the single highest-yield step in a lower-face plan.
Serial direct filling of the same crease without structural review. Each syringe seems reasonable; the sum is heaviness. If a fold keeps 'needing' filler every few months, the plan — not the product — deserves re-examination.
References
Rohrich RJ, Pessa JE. The fat compartments of the face: anatomy and clinical implications for cosmetic surgery. Plast Reconstr Surg 2007;119(7):2219–2227. source
