In short. A wrinkle lives in skin and can be filled flat. A fold is the junction between cheek and lip, so filling the groove widens the midface instead of softening it.
Key points
- Material placed along a crease disappears into the skin and the surface levels.
- Material placed along a junction has nowhere to disappear to, because the cheek and the lip are still at different levels on either side of it.
- It sits proud of both, and the midface gains width rather than support.
A patient points at the line running from the side of the nose to the corner of the mouth and asks for it to be filled. The request is reasonable, and the line is plainly there. It is also the request most likely to leave a midface looking heavier than it did before, and the reason lies in one word.
A wrinkle is a crease; a fold is a junction
A wrinkle lives in skin. It comes from that skin folding, thinning or losing elasticity, and material placed beneath it flattens the surface because the tissue on both sides sits at the same level. A nasolabial fold is not a crease in skin at all. It is the junction where the cheek meets the upper lip, and every face has one, visible in children when they laugh and in people who have never used a cream.
What has changed is the cheek
With time the cheek pad descends and drifts forward, the deep fat that held it high thins, and the bone beneath the midface remodels inward. The cheek now sits lower, and the junction between the two becomes a groove because the two sides are now at different levels. Nothing new has been created. The fold has simply been given something to separate.
Filling a crease and filling a junction
Material placed along a crease disappears into the skin and the surface levels. Material placed along a junction has nowhere to disappear to, because the cheek and the lip are still at different levels on either side of it. It sits proud of both, and the midface gains width rather than support.
Why the mistake is made so often
The fold is easy to point at, simple to photograph, and has a name that sounds like a fault. The treatment for a line is quick and widely offered. The reasoning is natural, and it skips the only question that decides the outcome: has the cheek moved? A plan made without that question is made from a photograph of the surface.
Where skin quality genuinely counts
Skin is not irrelevant to this. Loss of elasticity, sun damage and smoking all make the surface crease at the fold, and fine lines beside the mouth belong to the same picture. That contribution is real and it is modest: it changes how sharp the fold looks, not where the junction sits.
Ask before anything is injected
- Has the cheek been examined at rest and in a smile, or only the fold?
- Is the plan to treat the groove, or to support what has moved?
- Has anyone said plainly that the fold is reduced rather than removed?
What actually produces the fold, ranked by how much each cause can be changed, is set out in the guide to causes. What happens when that order is ignored is described in why a flat fill disappoints, and the case for leaving a normal fold alone is made in when no treatment is needed.
Frequently asked questions
If it is not a wrinkle, why does it look like one in the mirror?
Because a mirror shows a line and does not show what produced it. A crease in skin and a junction between two structures look the same from the front in flat light, and they behave in opposite ways when the cheek is lifted. The resemblance is the reason the mistake is made so often, by patients and by clinics alike.
Why do so many clinics offer to fill the fold?
Because filling a line is a quick, familiar and well-taught treatment, and the fold looks like a line. Offering it does not require anyone to have asked whether the cheek has moved. That question is the one that decides whether the treatment helps, and a plan that skips it is a plan made from the surface of the face.
Does that mean nothing can be done about it?
Quite the opposite. It means the thing to treat is the cheek rather than the groove. Support placed to restore a cheek that has lost volume, and a lift where the cheek has genuinely descended, both change the fold by changing what produces it. The fold is reduced rather than removed, and that limit is stated before treatment rather than discovered afterwards.
Risks & Limitations
- Filling the fold itself rather than the cheek widens the midface, and correcting that is harder than the original complaint.
- Material placed deep in this region can enter a vessel and obstruct the blood supply to skin, which is why the area is treated with more caution than most.
- Support placed to restore the cheek changes the midface without restoring a cheek that has genuinely descended.
- Thread lifting is temporary by design, and no rung on the ladder removes the fold itself.
When to Seek Care
- A fold that appeared over weeks, or is present on one side only.
- Weakness on one side of the face, numbness in the cheek or lip, drooling, or difficulty closing an eye — seek urgent care.
- Skin in a treated area that turns pale, grey, mottled or blistered, or severe pain after an injection.
- A lump that can be felt in the cheek or lip, or swelling with pain, redness or warmth.
References & Further Reading
- American Society of Plastic Surgeons (ASPS) — procedure and safety guidance
- National Institute for Health and Care Excellence (NICE, UK) — relevant guidance
- Cochrane Library — systematic reviews
- Chinese Medical Association Plastic Surgery Branch — clinical guidance
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.