The nasolabial fold is a natural anatomical line that extends from the wing of the nose to the corner of the mouth. This cutaneous contour, present in everyone, varies in appearance from one individual to another. Its depth, visibility, and evolution over time depend on facial morphology, muscular activity, and the ageing of the supporting tissues. Although it is commonly associated with the signs of ageing, it is present from a young age and contributes to the balance and expressiveness of the face.
Pour bien comprendre ce sillon, il est important d’en définir les caractéristiques anatomiques, les mécanismes qui conduisent à son apparition et sa signification esthétique. Plus qu’une simple ride, il s’agit d’une zone de transition entre plusieurs compartiments du visage. Il constitue aussi un repère essentiel, car il reflète à la fois l’expression du visage et les effets du vieillissement.
From an anatomical perspective, the nasolabial fold is a natural line located at the junction between the cheek and the upper lip. It separates two distinct aesthetic regions: the midface, dominated by the cheekbones and the malar fat compartments, and the perioral region, which plays a key role in speech, eating, and facial expression.
This line is accentuated by the difference in contour between the superficial tissues, which are more mobile and richer in fat, and the deeper tissues, which are more firmly anchored to the underlying bone. Consequently, the nasolabial fold is present in every individual at every age, although its depth varies considerably. It is barely visible in children, becomes more noticeable in young adults, and gradually deepens over time.
The nasolabial fold is a well-defined anatomical line located on each side of the face. It begins at the wing of the nose and extends obliquely downward to the outer corner of the upper lip, ending at the corner of the mouth. This natural line marks the boundary between two major aesthetic regions: the cheek, with its volume and mobility, and the perioral region, which is involved in speech, eating, and facial expression.
Although it is present in every individual from an early age, its appearance changes over time. In children and young adults, it is usually subtle and becomes visible mainly when smiling. With ageing, the progressive loss of skin firmness, depletion of facial fat compartments, and descent of the soft tissues contribute to its deepening. The nasolabial fold gradually becomes visible even at rest, sometimes giving the face a tired or severe appearance.
Its anatomical location therefore makes it an essential landmark in the assessment of facial ageing. Understanding exactly where the nasolabial fold is located and how it evolves over time not only helps to interpret the signs of ageing more accurately but also allows the development of natural and appropriate aesthetic treatment strategies.
The nasolabial fold plays an active role in facial dynamics and emotional expression. It forms and becomes more pronounced during the contraction of several perioral muscles, particularly the levator labii superioris, the zygomaticus major, and, to a lesser extent, the orbicularis oris muscle. These muscles are involved in smiling, laughing, speaking, and various reflex facial expressions.
Consequently, the nasolabial fold is not merely a static crease but also a dynamic anatomical feature that is closely linked to facial movement. The daily repetition of these expressions, combined with the gradual loss of skin elasticity over time, eventually leads to permanent dermal creasing, making the nasolabial fold visible even when the face is at rest.
The nasolabial fold should not be confused with a simple wrinkle. An expression wrinkle is a superficial crease of the dermis caused by the repeated contraction of facial muscles, such as those responsible for forehead lines or glabellar lines. In contrast, the nasolabial fold is a morphological fold, often deep, rooted in the anatomy of the face and accentuated by volume loss and the effects of gravity.
It also differs from a functional skin crease, which disappears when the face is at rest. Once the nasolabial fold becomes pronounced, it remains visible regardless of facial expression. It then becomes a permanent facial feature, often—sometimes incorrectly—associated with an appearance of fatigue, severity, or ageing.
The development of the nasolabial fold is based on a complex deep anatomical framework composed of the maxillary bone, the facial retaining ligaments, and the superficial and deep facial fat compartments. The maxillary bone, depending on the degree of its projection, partly determines the convexity of the cheek and, by contrast, the prominence of the nasolabial fold. Reduced projection of this bone, known as maxillary hypoplasia, can therefore make the fold visible at a very early age, sometimes even during childhood.
The retaining ligaments of the face, particularly the nasolabial ligament, act as anchoring structures by securing the soft tissues to the deeper anatomical layers. Over time, their suspensory capacity gradually decreases, leading to progressive tissue descent and a deepening of the nasolabial fold.
Finally, volume loss within the facial fat pads, especially the deep malar fat compartment, further contributes to this process. By altering the mechanical support that maintains the soft tissues, it accentuates the depth of the nasolabial fold even further.
In clinical practice, the nasolabial fold is one of the earliest visible signs of facial ageing. Its evolution generally follows a fairly predictable pattern: initially subtle and noticeable only when smiling, it gradually becomes visible at rest and is later accompanied by secondary folds, such as marionette lines and jowl folds.
This transformation does not simply reflect facial volume loss. It also results from the progressive deterioration of skin quality, as the skin becomes thinner, drier, and less firm, together with the weakening of the deeper supporting structures. The nasolabial fold should therefore not be regarded as an isolated phenomenon, but rather as the visible expression of a global process of tissue laxity and structural ageing affecting the face.
The prominence of the nasolabial fold varies considerably from one person to another. This variation depends on several factors, including genetics, facial bone structure, skin quality, and lifestyle habits. Repeated facial expressions, thin skin, under-projected cheekbones, and a broad smile can all contribute to the earlier development and deepening of the nasolabial fold.
These anatomical predispositions are further influenced by environmental and behavioural factors. Repeated sun exposure, smoking, significant weight fluctuations, and hormonal imbalances accelerate collagen degradation and reduce the skin's ability to withstand mechanical stress. Although these factors are not the direct cause of the nasolabial fold, they contribute to its earlier onset and greater severity.
In the collective imagination, the nasolabial fold carries a strong expressive significance. As it deepens, it is often spontaneously associated with a tired appearance, persistent sadness, or even a stern expression, although these impressions may not reflect the person's actual emotional state. This perception results largely from the way light and shadows fall across the face: the fold creates a distinct interruption in the continuity of the facial contours, making the face appear less open and less rested.
Beyond its purely anatomical characteristics, the nasolabial fold therefore becomes an important element of non-verbal communication. It influences how others perceive the face and the image a person projects in both social and professional settings. This perceptual dimension explains why many patients, as soon as the fold becomes noticeable, experience it as an aesthetic concern, regardless of their actual age or level of vitality.
The nasolabial fold initially appears as a subtle, temporary shadow that becomes visible during facial movements, particularly when smiling. At this stage, the fold is not permanent and disappears when the face is at rest. Gradually, as the skin loses firmness, the malar fat compartments descend, and skin thickness decreases, this shadow evolves into a deeper line that remains visible even in the absence of facial expression. This stage is referred to as a nasolabial fold at rest. In some individuals, mild sagging of the adjacent tissues or a loss of cheek projection may precede its appearance. Careful examination under natural light, combined with gentle palpation, can reveal the earliest signs of deepening, sometimes even before the patient becomes aware of them.
Article written by Dr Romano Valeria
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