When people seek cosmetic advice about facial aging, two terms frequently come up: nasolabial folds and smile lines. They’re often confused, used interchangeably, or misunderstood as the same thing.

While these features appear in similar areas of the face and become more noticeable with age, they’re not identical. Understanding the difference can help you recognize what’s happening beneath the skin, why these lines develop, and what options exist if you want to soften or treat them.

This article breaks down the anatomy, causes, and key differences between folds and smile lines, along with the most common approaches to prevention and treatment.

What Are Nasolabial Folds?

Nasolabial folds are the deep lines or creases that run from the sides of the nose down to the corners of the mouth. Everyone has nasolabial folds, they’re a natural part of human facial structure, present from childhood. What changes over time is their depth and visibility.

Why do nasolabial folds appear?

As you age, several anatomical changes make these folds become more pronounced:

Loss of collagen and elastin:
With time, your skin produces less collagen (which provides structure) and elastin (which allows skin to bounce back). This leads to sagging and folding of the mid-face.

Fat redistribution:
The cheek fat pads—which keep the mid-face plump and supported in youth—gradually shift downward. This descent contributes to the deepening of the fold.

Bone resorption:
The bones of the face subtly remodel as we age. Loss of bony support in the mid-face causes soft tissues to collapse inward.

Repeated facial expressions:
Smiling, laughing, and talking can increase the visibility of folds over time, though these expressions aren’t the primary cause.

Nasolabial are considered a structural feature more than a “wrinkle.” Even people who rarely smile will have them, and they tend to deepen with changes in volume, support, and elasticity.

What Are Smile Lines?

“Smile lines” is a broad, informal term that refers to wrinkles that appear when you smile. These are typically the faint lines that form around the mouth and may extend outward from the corners of the lips.

There are two types of smile lines:

Dynamic smile lines:
These lines appear only when you move your face, such as during smiling or laughing. They’re caused by repeated muscular contractions and are similar in nature to crow’s feet around the eyes.

Static smile lines:
Over time, dynamic lines may begin to show even when your face is at rest. This happens as the skin thins, loses elasticity, and stops bouncing back.

Smile lines are therefore considered expression lines—wrinkles formed from the movement of facial muscles.

Key Differences Between Folds and Smile Lines

Although the two are often mixed up, the differences are clear once you understand the structure and behavior of each feature.

1. Location

folds:
Run vertically from the nose to the corners of the mouth.

Smile lines:
Appear at the corners of the mouth or radiate outward from the lips when smiling.

2. Type of line

Nasolabial folds:
Anatomical folds created by the structure of the face.

Smile lines:
Wrinkles or creases caused by repeated facial expressions.

3. Movement

Nasolabial:
Visible even when the face is at rest.

Smile lines:
Mostly visible during facial movements, at least in their early stages.

4. Causes

Nasolabial:
Primarily caused by volume loss, fat descent, and aging of deeper structures.

Smile lines:
Mainly due to repeated muscle movement and loss of skin elasticity.

5. Treatment approaches

Because the underlying causes are different, treatment methods vary:

Nasolabial often respond to volume restoration—such as dermal fillers or lifting techniques.

Smile lines may benefit more from skin-focused treatments or muscle-relaxing options, depending on type.

Why the Confusion?

Many people assume smile lines are the same as nasolabial because both sets of lines appear around the mouth and become more noticeable with smiling. In photographs, they can blend together visually, making it tricky to differentiate. Additionally, both deepen with age and are common reasons people seek aesthetic treatment.

The overlap in location and behavior contributes to their mistaken identity.

How to Prevent or Minimize Folds and Smile Lines

While you can’t stop natural aging, several lifestyle habits and skincare practices can slow down the progression of both nasolabial and smile lines.

1. Protect your skin from the sun

UV exposure accelerates collagen loss and skin thinning. Daily SPF use is one of the most effective strategies for preventing premature wrinkles.

2. Maintain skin hydration

Well-hydrated skin appears smoother and more resilient.

3. Use collagen-supporting skincare

Ingredients such as retinoids, vitamin C, and peptides support collagen production and help reduce fine lines.

4. Avoid smoking

Smoking dramatically accelerates wrinkle formation around the mouth.

5. Maintain stable weight

Significant weight fluctuations can contribute to facial volume loss and deepened folds.

Non-Surgical Treatment Options

1. Dermal Fillers

Hyaluronic acid fillers are often used to treat folds. They don’t erase the fold, but they can soften its appearance by restoring volume to the mid-face or directly into the fold.

2. Botox (Botulinum Toxin)

Botox is commonly used for smile lines that appear due to muscle movement. It relaxes the muscles responsible for dynamic wrinkles.

3. Skin Treatments

For fine, superficial smile lines:

·       Microneedling

·       Laser resurfacing

·       Chemical peels

·       Radiofrequency treatments

These approaches improve skin texture and stimulate collagen production.

4. Thread Lifts

PDO or PLLA thread lifts can provide mild to moderate lifting in the cheek area, reducing the appearance of nasolabial.

5. Fat Transfer

For those seeking a more permanent solution, fat grafting can restore mid-face volume and support the nasolabial region.

Surgical Treatment Options

Facelift or Mid-Facelift

For deep folds caused by significant tissue descent, surgical lifting offers the most dramatic and long-lasting improvement. By repositioning deeper structures, a facelift directly addresses the root cause.

When to Seek Professional Advice

If your lines are becoming more pronounced and you’re unsure whether they’re nasolabial, smile lines, or a combination of both, a consultation with a dermatologist or aesthetic provider can help. Understanding the exact cause of your concerns ensures that the right treatment plan is chosen—one that targets the correct anatomical structures.

Conclusion

Nasolabial folds and smile lines both contribute to expressions of joy, laughter, and humanity. While they often coexist and may appear similar, they stem from different anatomical and functional causes. folds are structural creases that deepen with age and loss of volume, while smile lines are expression-driven wrinkles that form through movement and skin aging.

Recognizing the difference empowers you to make informed decisions about skincare, lifestyle habits, and aesthetic treatments. Whether you embrace these lines as part of your natural expression or explore ways to soften them, understanding their origins is the first—and most important—step.