Smile Lines: The 5 Types, Where Each Sits, and How Each Is Treated (2026)

Most people searching for smile lines are not describing the same crease. Some mean the fine vertical lines on the lip border, some the lines fanning from the outer corners of the eyes, some the downturn at the mouth corners, and some the fold running from nose to mouth. They sit in different places, come from different mixes of muscle, volume and skin quality, and need different products. Picking a treatment before identifying the line is the main reason people are disappointed with a result.

This guide names each type of smile line, says where it sits and what causes it, matches a treatment to each, and states the plain FDA status. It closes with prevention and early intervention, which matter more here than for most facial concerns. This is educational information, not medical advice.

Smile lines is a name for five different creases

Clinicians rarely say smile lines, because the phrase groups creases that have separate names and separate treatments. Five distinct lines get called smile lines. Perioral lines are the fine vertical lines running up from the upper lip border and down from the lower lip, often called lip lines or smoker's lines even in people who never smoked. Oral commissure lines are the short creases and downturn at the corners of the mouth. Marionette lines continue from those corners toward the jawline. Lateral canthal lines, or crow's feet, fan from the outer corner of each eye when you smile. The nasolabial fold runs from the side of the nose to the outer mouth corner.

A sixth pattern confuses people: mid cheek or accordion lines, the diagonal creases that appear on the cheek in a broad smile. These are almost entirely dynamic in younger faces and among the hardest to treat, because the movement creating them is movement people want to keep.

Identifying your own is a two step mirror test. Relax completely and note what is still visible, then smile fully and note what appears or deepens. A line present at rest is static and needs volume or skin remodelling. A line that appears only on movement is dynamic and responds to relaxing the muscle behind it. Most adult faces have both.

(table) Line type : Where it sits : Typical treatment : Plain FDA status; Perioral or vertical lip lines : Vertical lines on and above the upper lip border and below the lower lip : Fine hyaluronic acid filler, resurfacing laser, micro dosed botulinum toxin : Restylane Silk and Juvederm Volbella XC are FDA approved for perioral lines in adults over 21; botulinum toxin here is off label; Oral commissure lines and corner downturn : At the corners of the mouth : Small volume filler, botulinum toxin to the muscle that pulls the corner down : Off label for both filler and toxin at this specific site; Marionette lines : From the mouth corners down toward the jawline : Hyaluronic acid filler, biostimulators such as Sculptra or Radiesse : Usually off label, since most filler labels name nasolabial folds rather than marionette lines; Lateral canthal lines or crow's feet : Fanning from the outer corner of each eye : Botulinum toxin, plus resurfacing for etched static lines : Botox is FDA approved for lateral canthal lines; other toxins are approved for frown lines only, so their use here is off label; Nasolabial fold : From the side of the nose to the outer mouth corner : Hyaluronic acid filler, Radiesse, Sculptra, cheek support : FDA approved for moderate to severe nasolabial folds; Mid cheek or accordion lines : Diagonally across the cheek during a broad smile : Skin quality treatments, conservative volume support : Off label, and often best left untreated

Dynamic smile lines and static smile lines behave differently

Every smile line starts dynamic. A muscle pulls the skin into a crease, and when it relaxes the skin springs back flat. That spring back depends on collagen and elastin, both of which decline from the mid twenties. As skin thins, the same fold stops recovering fully and a faint line remains at rest: a static or etched line.

The distinction predicts what works. Botulinum toxin reduces the muscle pull behind a dynamic line, so it performs well on crow's feet and poorly on a deep structural fold. Fillers replace lost volume, suiting static creases and descended tissue. Resurfacing lasers and radiofrequency microneedling rebuild collagen in the skin itself, the best option for an etched line with nothing meaningful to fill. Treated early, a dynamic line tends to stay dynamic longer, while a line etched over years usually needs more than one method, because relaxing the muscle does not undo collagen already lost.

Perioral and vertical lip lines are their own problem

Perioral lines run perpendicular to the lip border, driven mainly by the orbicularis oris, the ring shaped muscle that purses the lips, combined with unusually thin skin and almost no underlying fat. Smoking accelerates them through both repeated pursing and direct collagen damage, which is where the smoker's lines name comes from, but non smokers get them too. Straws, wind instruments, genetics and sun all contribute, and sun matters more here than almost anywhere else because the skin is so thin.

Treatment differs genuinely from anything used on the nasolabial fold. Very fine, soft hyaluronic acid fillers are placed superficially along the lip border and into individual lines, and two products carry a specific FDA approval here: Restylane Silk and Juvederm Volbella XC are FDA approved for correction of perioral lines in adults over 21. Botulinum toxin can soften the pursing muscle in tiny doses, but that use is off label, and over treating it interferes with speech and drinking.

Resurfacing is often more effective for deeply etched lip lines. Fractional CO2 and erbium lasers, and to a lesser degree radiofrequency microneedling and chemical peels, remodel the thin skin so the grooves become shallower. Downtime is real and pigment change is a risk, particularly in deeper skin tones. Filler placed into lip lines without addressing skin quality can look lumpy, precisely because the skin is so thin.

Mouth corner lines and the marionette boundary

The mouth corner is a separate problem again. The depressor anguli oris, the muscle that pulls the corner downward, becomes relatively stronger than the muscles that lift it, so the resting mouth angle turns down, while the tissue just outside the corner loses support and a short crease forms.

Treatment usually combines a very small amount of botulinum toxin into that depressor muscle with a small volume of filler to support the corner. Both uses are off label at this site and both demand precision, since too much toxin alters the smile and too much filler blunts the natural corner shape. Marionette lines, running from the corner toward the jawline, are a related but distinct crease, treated with filler along the line plus chin and jawline support beneath it. Most filler labels name nasolabial folds rather than marionette lines, so this is typically off label placement of an approved product.

Smile lines at the outer eyes are the one type with a clear approval

Lines fanning from the outer corner of each eye when you smile are lateral canthal lines, or crow's feet. They come almost entirely from the orbicularis oculi squeezing during a smile or squint, combined with the thinnest skin on the face. Because they are so movement driven, they have the clearest regulatory position of any smile line: Botox is FDA approved for temporary improvement of moderate to severe lateral canthal lines in adults. Other toxin brands sold in the United States are approved for frown lines, so using them at the outer eye is off label.

Two caveats. Chronic squinting from an uncorrected prescription or from glare drives these lines hard, so an eye exam and sunglasses do more than people expect. Once the lines are etched at rest, toxin softens but does not clear them, and resurfacing is added. Filler is used cautiously here because thin skin shows product.

The nasolabial fold is one member of the family

The nasolabial fold, from the side of the nose to the outer mouth corner, is the line most often meant when someone says smile lines in a clinic. It differs because it is largely structural: the cheek fat pad above it descends onto a fixed anatomical boundary, so it deepens without much muscle activity. That is why botulinum toxin does little for it, and why hyaluronic acid fillers, Radiesse and Sculptra, all FDA approved for moderate to severe nasolabial folds, are the standard approach.

Because that fold has its own anatomy, approved products and safety profile, it is covered separately and in depth. For causes, treatment options, longevity, cost drivers and the vascular risk specific to that region, read the [nasolabial folds guide](/guides/nasolabial-folds).

Choosing between a neuromodulator and a filler by line type

The decision simplifies once the line is identified. Ask what creates the crease. If a muscle folds the skin and the line largely disappears at rest, a neuromodulator is the logical first step: that describes crow's feet clearly, and in micro doses and off label the mouth corners and fine lip lines. If the crease is present at rest and the tissue around it looks deflated or has slid downward, filler or a biostimulator comes first: that describes the nasolabial fold, marionette lines and most etched perioral lines.

Two rules follow. Treat structure before the line, because supporting a deflated cheek or a receding chin often improves the crease below it more than injecting the crease does, and looks more natural. And treat skin quality alongside either, since neither toxin nor filler improves the texture of thin, sun damaged skin. Be wary of a plan that answers every line type with the same product: a provider proposing filler for crow's feet, or toxin for a deep nasolabial fold, is treating the label rather than the anatomy.

Prevention and early intervention change the trajectory

Prevention has more leverage on smile lines than on most facial concerns, because several start dynamic and only become permanent once collagen loss lets the crease set. Daily broad spectrum sunscreen of at least SPF 30 is the most evidence backed step, since ultraviolet exposure is the largest preventable driver of collagen and elastin breakdown. Sunglasses matter specifically at the outer eye, cutting both the squinting that drives crow's feet and the direct exposure.

Not smoking protects the collagen and blood supply the skin depends on, and removes the repeated pursing that etches lip lines. A topical retinoid, prescription tretinoin or over the counter retinol, is the best studied active for building collagen and thickening skin over months, and is particularly relevant for thin perioral skin. Antioxidants add modest daily protection, moisturizing makes fine lines look softer without reversing a crease, and stable body weight avoids the loose skin that follows large losses.

Sleep position is the one people dismiss: sleeping face down or always on the same side compresses the cheek and perioral skin for hours nightly, and those creases can become fixed over years. Facial exercises and massage are widely promoted online, but evidence that they reduce these lines is weak. Early intervention is real but oversold: small, conservative doses of botulinum toxin started while a line is still dynamic reduce how deeply it folds, and there is reasonable evidence this slows the shift to an etched line, which is not the same as preventing aging. Sun protection and a retinoid in your twenties beat any injectable at that age.

Results, risks, and safety vary by where the line sits

Outcomes differ by line type. Botulinum toxin appears over three to seven days, peaks near two weeks and typically lasts three to four months. Hyaluronic acid filler is visible immediately, settles over one to two weeks and lasts roughly six to eighteen months depending on product, site and movement. Sculptra and Radiesse build gradually across a series and can last longer. Resurfacing works over weeks to months. The goal is softening rather than erasure, and any promise of permanent or complete removal should be treated with suspicion.

Risk varies by site. The most serious filler risk is accidental injection into a blood vessel, called vascular occlusion, which can cause skin death and, very rarely, vision loss, and that risk is highest around the nose and between the brows. Around the mouth the practical risks are lumpiness and visible product in thin skin, plus more swelling and bruising than elsewhere. Around the eyes, toxin can spread and cause a temporary eyelid droop or an uneven smile, and superficial filler can show as a bluish tint. Hyaluronic acid can be dissolved with hyaluronidase, which biostimulators cannot. What most changes these odds is who holds the needle, so choose a licensed provider in a medical setting who treats these areas routinely.

Cost considerations across the line types

These are cosmetic treatments, so insurance does not cover them. Prices vary by region, provider experience and product, so treat any figure as a range, not a quote. Botulinum toxin is usually priced per unit or per area, and the doses used at the mouth and outer eyes are small, so those sessions often cost less than filler. Hyaluronic acid filler is priced per syringe, and fine lip line work may use only part of one.

Because everything here is temporary, budget annually: toxin repeats roughly every three to four months and filler roughly every six to eighteen. Resurfacing is usually sold as a package of sessions. Prices far below the local norm are a warning sign rather than a bargain, since they can indicate diluted product, an inexperienced injector or a non medical setting. Ask for an itemised plan stating the product, the amount and the expected number of sessions.

When to see a provider about smile lines

There is no medical need to treat any of these lines, so the decision is personal. A consultation is worth booking when a line is visible at rest and bothers you, when skincare has stopped making a noticeable difference, or when you cannot tell which line you are looking at and want it named before you spend anything. That last reason is the most under used, because an accurate assessment often redirects people to a cheaper or more appropriate treatment.

Look for a licensed medical professional, a board certified dermatologist or plastic surgeon, or an experienced nurse practitioner or physician assistant under proper medical supervision, ideally someone who treats the mouth and eye areas routinely, since those demand more precision than larger facial zones. A good consultation names the specific line, says whether it is dynamic or static, states which uses are FDA approved and which are off label, and covers cost and maintenance without pressure. When you are ready, injector.world can connect you with qualified providers near you.