Smile Lines: Causes and How to Get Rid of Them

Smile lines, or nasolabial folds, usually reflect three things: lost volume in the cheek compartments above them, laxity of the skin and soft tissue, and repeated muscle movement around the mouth. Getting rid of smile lines means treating whichever dominates, often cheek support first, rather than filling the crease alone. Some line is normal in every adult face.

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

In this guide

Why these lines form
Why filling the crease alone disappoints
Smile lines treatment in Singapore: treating the cause, support first
What honest results look like
Can skincare or face exercises get rid of smile lines?
Smile & Marionette Lines — Frequently Asked Questions
Related
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In brief

Smile lines are the creases running from the sides of the nose to the corners of the mouth, called nasolabial folds in medicine. Getting rid of smile lines completely is not realistic; softening them means treating the cause: lost cheek support, laxity or muscle movement. Filling the crease alone often disappoints.

Lifting without adding volume. For smile and marionette lines, Dr Sin Yong's first choices are his own protocols, the VF Lift – Vertical Facelift (monopolar radiofrequency on Volnewmer) and Time Freeze Laser LCLR® (dual-wavelength laser). Both work on your own tissue. Nothing is injected, so there is no filler to overfill, migrate or form lumps. Which one suits you, if either, is decided at assessment.

Why these lines form

Rohrich and Pessa's 2007 study of thirty hemifacial cadaver dissections 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. A 2018 web-based survey of 3,553 adults who rated their own faces against photonumeric scales found that a greater midface volume deficit went with more severe nasolabial folds, after allowing for age.

Smile lines deepen with expression and soften at rest. Illustrative video, not a patient.

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

Smile lines treatment in Singapore: 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. At the clinic on Orchard Road, Singapore, Dr Sin Yong plans and performs each step himself; the options for the fold itself are set out under nasolabial folds treatment Singapore.

Smile lines vs marionette lines: what drives each, and what is used

Smile lines and marionette lines sit close together but have different drivers, so they are planned differently. Smile lines are mostly about the cheek above them. Marionette lines involve the jowl, the muscle that pulls the mouth corner down and the support around the chin.

	Smile lines (nasolabial folds)	Marionette lines
Main driver	Deflated, descended cheek fat pressing on the fold	Jowl descent, a downturned mouth corner and loss of chin support
First step usually considered	Restoring cheek support above the fold	Support beside the chin and at the jowl border, and assessing the jowl
Muscle factor	Small: the fold is mainly tissue position	Larger: the muscle that pulls the mouth corner down can be relaxed with small doses of botulinum toxin
Lifting	Where midface laxity is present	Where the jowl is the main cause
Filler into the line itself	A small amount, after support, if a crease remains	Cautious: too much adds weight to the lower face

Most faces have both lines, and they are planned together, because supporting the cheek also changes how much tissue reaches the jowl. The fold itself is treated last, if at all. Where the jowl dominates the lower face, the options for it are set out on jowls and lower face sagging; for the fold on its own, see nasolabial folds treatment.

Dr Sin Yong assesses both lines at rest and in a smile, and checks for earlier filler with ultrasound before adding anything, because a heavy-looking lower face is sometimes old product rather than lost support.

Why do I have smile lines at a young age?

Smile lines at a young age are usually normal anatomy rather than early ageing. Every face that smiles folds at the nasolabial line, and in some faces the fold shows at rest from the twenties. Bone shape, cheek fullness, expression habits and weight change decide how early it appears, and a large online study of adults found that the more volume the midface had lost, the deeper the smile lines were rated.

What makes smile lines show early

Bone support. The upper jaw beside the nose and under the cheek supports the fold. CT studies of East Asian faces show this midface skeleton changing with age, and a flatter or set-back midface can let the fold show sooner.
Cheek fullness. A full, round cheek folds more deeply when it rests against the fixed tissue around the mouth.
Expression. Strong, frequent smiling creases the same line many times a day.
Weight change. Losing facial fat, especially quickly, reduces cheek support.
Sun and smoking, which thin the collagen that lets skin spring back.
Teeth and bite. Changes in lip support after orthodontic work or tooth loss alter how the area folds.

Lookalikes a doctor separates

A crease that appears only when you smile is different from a fold that stays at rest. A groove running diagonally across the mid-cheek is not the smile line, and a dip in front of the jowl is not the marionette line, although both are mistaken for them. Fine vertical lines on the lips are a separate skin-quality problem. In a face that has had filler before, heaviness beside the mouth is sometimes old product, which is why earlier filler is checked before anything is added.

What you can do at home, and what you cannot

Daily sunscreen, not smoking and keeping your weight steady protect the skin and support. A retinoid can refine surface lines. No cream, gua sha tool or face exercise changes a fold cast by bone and fat position.

When to see a doctor about smile lines

A sudden change on one side, such as one smile line flattening or one corner of the mouth drooping, is a medical emergency until stroke or facial nerve palsy is excluded. Pain, blanching or dusky skin after filler needs the injecting doctor the same day. Otherwise, assessment is a choice: the options are set out on nasolabial folds treatment, marionette lines treatment and cheek fillers.

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.

Key takeaways

Smile lines and marionette lines are the visible creases of a structural shift: cheek fat compartments deflate and descend onto the fixed tissue around the mouth.
Filling the crease alone can make the lower face heavy, because the tissue above it is still descending; cause-first treatment restores cheek and lateral support first.
Marionette lines also involve the jowl and the muscle that pulls the mouth corner down, which can be relaxed with small doses of botulinum toxin.
Earlier filler is checked with ultrasound before anything is added, because heaviness beside the mouth is sometimes old product rather than lost support.
No cream, gua sha tool or face exercise changes a fold cast by bone and fat position, although sunscreen, not smoking and a steady weight protect the skin and its support.
A sudden change on one side, such as one corner of the mouth drooping, is a medical emergency until stroke or facial nerve palsy is excluded.

Can skincare or face exercises get rid of smile lines?

Skincare and face exercises cannot remove a smile line, because the main causes sit deeper than either reaches. A nasolabial fold forms where descending cheek tissue meets the fixed anatomy around the mouth; no cream restores deflated fat compartments, and no exercise reverses laxity in the supporting tissue.

Skincare still has a role at the level of the skin. Daily sunscreen limits ultraviolet damage to collagen, and a prescription or over-the-counter retinoid can improve fine surface lines and texture over months, but neither changes the depth of a fold cast by a shift in volume. Facial exercise programmes are popular, yet the evidence for them is limited, and repeated strong smiling and puckering work the same muscles that deepen expression lines. Massage tools and tapes may reduce puffiness briefly without changing structure. Rapid weight loss and smoking also influence how the lower face ages. Where a line bothers you, assessment identifies which of volume, laxity or movement is driving it, and that decides whether filler, energy-based lifting, threads or botulinum toxin is relevant at all.

Smile line and marionette line treatments compared by cause
Option	What it does	What it cannot do	Typical recovery	Who it tends to suit
Midface structural volumisation (dermal filler in the cheek)	Restores support in deflated cheek compartments so less tissue folds onto the nasolabial line	Does not tighten lax skin or change muscle pull at the mouth corners	Possible swelling or bruising at injection points that settles	Smile lines driven mainly by volume loss in the cheek
Direct filler in the fold, in moderation	Softens the remaining shadow once structural support is in place	Cannot counter tissue still descending from above; repeated filling makes the lower face heavy	As for other filler	A residual crease after midface work
Energy-based lifting, such as VF Lift – Vertical Facelift (Volnewmer monopolar radiofrequency)	Heats the dermis and subcutaneous layer to prompt collagen remodelling where laxity dominates	Does not replace lost volume or relax muscle	Usually transient redness and warmth	Lines linked to laxity and loss of firmness
Thread lift (The Bliss Lift)	Absorbable threads reposition descended midface tissue along a chosen vector	Does not restore volume or improve skin quality	Swelling, tenderness or bruising along the thread paths	Moderate descent where repositioning helps
Botulinum toxin to the depressor anguli oris	Relaxes the muscle that pulls the mouth corners down	Does not treat the nasolabial fold itself or replace volume	Small injection marks; the effect develops over the following days	Marionette lines with downturned mouth corners
Surgical facelift (referred to a plastic surgery specialist)	Repositions deeper tissue and removes excess skin surgically	Is not a non-surgical option, and does not restore volume on its own	A formal surgical recovery set by the operating team	Advanced laxity beyond what non-surgical approaches address

Smile & Marionette Lines — Frequently Asked Questions

Smile line filler in Singapore should be injected by a doctor. Dermal fillers are medical devices registered with the Health Sciences Authority, and injecting them is the practice of medicine, so it is done by a doctor registered with the Singapore Medical Council. Dr Sin Yong examines both lines at rest and in a smile, checks for earlier filler with ultrasound, and performs any treatment himself.

Smile lines can be softened without filler when laxity, rather than lost volume, is the main cause. Energy-based lifting such as the VF Lift – Vertical Facelift, monopolar radiofrequency on Volnewmer, heats the deeper skin to prompt collagen remodelling, and a thread lift can reposition descended midface tissue. Neither replaces lost cheek volume, and no cream or exercise removes a fold, so the cause is assessed first.

Smile lines do not go away on their own once they show at rest, because they reflect bone shape, cheek fat position and skin quality, which change gradually with age rather than reverse. Sunscreen, not smoking and a steady weight protect the skin and its support. Treatment can soften a fold but not erase it, and a sudden change on one side needs prompt medical attention.

Marionette lines are the lines that run down from the corners of the mouth towards the chin, named after a puppet’s hinged jaw. They form as the jowl descends, support around the chin thins, and the muscle that pulls the mouth corners down becomes more dominant, which can make the face look sad or stern at rest. They are different from smile lines, which run from the nose to the mouth corner.

Smile lines cannot be erased, and some line is normal in every adult face, but they can be softened by treating what deepens them. That usually means restoring cheek support above the fold, lifting where laxity dominates, and only then a small amount of filler in the line if a crease remains. Sunscreen, not smoking and a steady weight help at home; creams and face exercises do not change the fold.

Yes. Laugh lines, the creases from the sides of the nose to the corners of the mouth, are present in almost every face that smiles, including in teenagers and people in their twenties. They usually deepen gradually with age, sun, weight change and loss of cheek support. A line is only a concern if it bothers you, or if one side changes suddenly, which needs prompt medical attention.

Yes, in everyday speech. Nasolabial fold is the medical name for the crease from the side of the nose to the corner of the mouth, and smile line is the common name. Laugh lines usually mean the same crease. Marionette lines are different: they run down from the corners of the mouth and have different causes.

Sometimes, indirectly. When a marionette line is deepened by a descending jowl, tightening the lower face with radiofrequency or focused ultrasound can reduce how much tissue folds there. Neither treats a line driven mainly by lost chin support or by the muscle that pulls the mouth corner down. The cause decides whether energy treatment is part of the plan.

Usually not as the first step. Smile lines mostly reflect lost volume in the cheek compartments above them, laxity of the skin and soft tissue, and repeated movement around the mouth, so support is often restored in the cheek before the crease itself is considered. Filling the fold alone tends to add weight beside the mouth. A small amount of soft filler in the line is reserved for what remains once the cause has been treated.

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. The right choice 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.

How long structural volumisation is maintained varies with the product, area and individual; muscle-relaxant effects wear off over time; 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 often the first step considered 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.

A faint nasolabial line is visible in most faces from youth, especially when smiling, and it is normal. It tends to deepen from the thirties onwards as the cheek compartments lose volume and descend, though genetics, facial structure, sun exposure, smoking and weight change shift the timing considerably. What is causing the line in your face matters more than your age.

Not for the nasolabial fold itself. Botulinum toxin relaxes muscle, and the fold is mainly caused by volume loss and descent, so relaxing the muscles around it can flatten the smile and look unnatural. Botulinum toxin does have a role for marionette lines, where relaxing the depressor anguli oris lifts downturned mouth corners, and for a gummy smile, which is a separate concern.

They can. Losing facial fat, particularly quickly, reduces support in the cheek and lets the fold look deeper, which is why significant weight loss sometimes changes the lower face more than people expect. Where weight has changed, the plan accounts for where volume has been lost rather than simply adding filler to the crease.

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