Why Are My Nasolabial Folds (Smile Lines) So Noticeable? 8 Causes and What You Can Do Now, Explained by a Doctor

Cause 1Skin aging and loss of firmness

When the skin loses firmness due to factors such as UV exposure and dryness, expression lines may begin to remain visible even when the face is relaxed.

Beneath the skin’s surface lies the dermis, a layer containing collagen, elastin, and hyaluronic acid that provides structural support to the skin.

Patients sometimes ask about the difference between collagen and hyaluronic acid. In simple terms, collagen acts like a network of fibers, while hyaluronic acid is a gel-like substance that holds water.

Accumulated damage from UV exposure, dryness, smoking, stress, and glycation can reduce skin firmness and elasticity, making wrinkles more visible. As the skin becomes less able to support the cheeks, shadows related to sagging may also become more pronounced.

Everyday measures include moisturizing, sun protection, balanced nutrition, adequate sleep, and not smoking. People with dry or dehydrated skin should pay particular attention to moisturizing.

For a more complete overview of home care, see our guide to preventing and caring for nasolabial folds.

Cause 2Repeated movement of facial muscles around the mouth

Repeated movements while eating, speaking, and smiling, combined with a loss of skin firmness, can make lines persist over time.

The muscles around your mouth repeatedly contract and relax as you eat and speak. Expression lines tend to form over areas that move frequently. As the skin loses elasticity, those lines may remain even after your face returns to a relaxed expression.

Think of folding a piece of paper along the same line over and over: the crease eventually remains even when you flatten the paper. Similarly, repeated movements of the mouth together with changes in the skin can make creases more persistent.

One thing you can observe is whether a crease remains after you smile gently in front of a mirror and then relax your face. However, this observation alone cannot determine the cause or whether treatment is necessary.

Be cautious if facial exercise routines put considerable strain on the nasolabial fold area. If you notice discomfort or worsening lines, stop and reassess.

Cause 3Muscle and fat volume in the cheeks

When cheek tissue overlaps the outer side of a nasolabial fold, it can create a change in contour that makes the shadow appear deeper than the actual line.

The amount of muscle and fat in the cheeks influences how nasolabial folds look. Fuller cheeks may create a more pronounced step between the area outside and inside the fold, emphasizing its shadow.

Muscles

People with more developed facial muscles, or a habit of moving the mouth forcefully, may place more strain on the nasolabial fold area while smiling. However, skin quality and bone structure must also be considered.

Fat

Fuller cheeks can create a change in contour that casts a deeper shadow along the nasolabial fold. Conversely, people with little cheek fat may also have visible sagging or shadows if reduced skin firmness or structural hollows are present.

Fat compartments related to this area include malar fat, buccal fat, and jowl fat.

Cause 4Facial bone structure and age-related skeletal changes

The shape of the bone supporting the area beside the nose, and age-related facial bone remodeling, can contribute to hollows and changes in contour in the upper part of the fold.

Natural facial bone structure

Your underlying bone structure affects the appearance of nasolabial folds. For example, prominent cheekbones can create changes in contour between the inner and outer cheek, producing a more noticeable shadow.

A hollow at the base of the nostril can make the upper part of the nasolabial fold appear deeper. Jaw size, tooth alignment, and other structural features around the mouth may also play a role.

Age-related remodeling of facial bones

With age, facial bones can change in shape and the support they provide. Changes in the maxilla, which supports the area beside the nose and upper nasolabial fold, may contribute to more prominent hollows in this region.

Bone structure is not the only factor. Supporting ligaments, fat, muscles, and skin also influence facial appearance, so we do not select a treatment on bone structure alone.

Cause 5Gravity and skin sagging

As the tissues supporting the cheeks become weaker, downward movement under gravity can make shadows and changes in contour more visible.

Gravity is unavoidable. As the skin loses collagen and elastin and cheek support weakens, cheek tissue may descend and overlap the outer edge of the nasolabial fold.

You may notice that your smile lines look less prominent when looking into a mirror or phone camera while lying down. This can happen because the direction of gravity changes, altering the contours and shadows created by the cheeks.

However, less visible folds when lying down do not necessarily mean sagging is the only cause. Persistent skin creases and hollows beside the nose should also be assessed.

Cause 6Rapid weight loss

When cheek fat decreases over a short period, hollows or sagging can become more noticeable depending on the person’s skin firmness and bone structure.

Rapid weight loss can make nasolabial folds more apparent. If cheek fat is lost quickly, sagging and lines may become more visible while the skin adjusts to the change.

This may be especially noticeable in people who already have reduced skin firmness. On the other hand, in someone with fuller cheeks, fat loss can sometimes reduce the shadows. The effect varies from person to person.

Cause 7Changes in the cheeks after fat-dissolving injections or liposuction

After reducing cheek fat, wrinkles or sagging may become more noticeable if the amount removed is not well matched to the skin’s remaining firmness.

Some patients tell us that smile lines or wrinkles became more visible after fat-dissolving injections or liposuction. Reducing the fat may reveal preexisting loss of skin firmness or sagging. Particular caution may be appropriate from the 40s onward, when sagging becomes more common.

The result depends not only on age, but also on where and how much fat was removed, the original fat volume, skin condition, and bone structure. Anyone considering cheek fat reduction should discuss the possibility of future hollows or sagging, not only the immediate slimming effect.

Cause 8Changes around the mouth after dental or oral surgery

If smile lines look different after orthodontics, tooth extraction, or jaw surgery, it is important to consider facial shape, weight, facial movement, and aging rather than assuming the dental procedure is the only cause.

Some patients begin to notice their nasolabial folds after dental treatment, particularly orthodontics, extractions, or jaw surgery.

Jaw surgery, which changes the skeletal structure itself, can noticeably alter the shape of the mouth area. By contrast, orthodontic treatment or extractions alone do not necessarily cause dramatic changes in facial bone structure. Weight changes during treatment, how the mouth is used, chewing habits, expressions, and aging can all be involved.