Why we lose definition in the jaw and cheeks with age

Look at a photograph of yourself from 15 or 20 years ago. Often, the biggest difference is not in the wrinkles, but in the shape of the face. The cheekbones were higher and fuller, the transition between the eyelid and the cheek was smooth, and the jawline drew a sharp contour from the chin to the ear. Over time, the face goes from an "inverted triangle", wider at the top, to a squarer or "pear" shape, with more weight at the bottom.

For a long time, this was explained only by "skin that sags". Today we know it is much more than that. The face ages in all layers at the same time: the bone remodels, fat changes in volume and position, the ligaments that hold the tissues lose firmness and the skin loses elasticity. Understanding this explains why a cream on its own does not redefine a jawline, and what can really help.

The face in layers: what changes in each

Think of the face as a tent: the bone is the structure, the fat and muscles are the filling, the ligaments are the ropes that hold the canvas, and the skin is the canvas. With age, all the parts change.

1. Bone: the structure shrinks

The skeleton of the face is not static. Throughout adult life, some areas lose bone (resorption) selectively (Mendelson and Wong, 2012):

• Eye sockets: they widen, especially at the top and at the lower outer part, which contributes to deeper-set eyes and more marked dark circles.
• Upper jaw (maxilla): it recedes and loses projection, reducing support for the cheekbones and the base of the nose.
• Lower jaw (mandible): a CT study of adults in three age groups showed that the length and height of the mandible decrease with age, in both sexes (Shaw et al., 2010). In women, many of these changes had already occurred between youth and middle age; in men, mainly between middle age and old age.
• Tooth loss: greatly accelerates resorption of the lower and upper jaw bone, with an impact on the contour of the mouth and chin.

With less structure underneath, the soft tissues have less support. It is like lowering the tent poles: the canvas becomes slack.

2. Fat: less volume where it was needed, more where it was not

The fat of the face is organised into superficial and deep compartments (Rohrich and Pessa, 2007). Imaging studies suggest that, with age, some deep compartments of the midface (those that support the cheekbones) lose volume, while some superficial compartments tend to slide downwards (Gierloff et al., 2012). The result is a redistribution: less volume in the upper areas and more weight in the lower areas.

3. Ligaments: the "ropes" become loose

Retaining ligaments are fibrous structures that anchor the skin and soft tissues to the bone at strategic points: beside the eye socket, on the cheekbone, along the jaw (Alghoul and Codner, 2013). With age, the areas between these anchor points become looser, while the anchor points themselves stay relatively firm. That is why ageing is not a uniform descent: it forms "steps" and grooves precisely at the boundaries of these ligaments.

4. Muscle

The muscles of facial expression change in tone and shape with age. In the neck, the platysma muscle (a thin sheet beneath the skin) can become more visible in vertical bands and contribute to pulling the contour of the jaw downwards.

5. Skin: less elastic, less able to hold

The skin loses collagen and elastin with age and, above all, with the sun. It becomes thinner and less able to retract. In women, the first years after the menopause bring a faster loss of collagen (Brincat, 2000). Less elastic skin over a support that has diminished accentuates everything else.

The cheeks: what happens to the midface

The midface (from the lower eyelid to the corner of the mouth) is often where ageing begins to show in the contour. In a young face, the cheekbone forms a continuous, convex, high curve that extends smoothly to the lower eyelid. Plastic surgeons sometimes call it the "S-curve" or "ogee" seen in three-quarter view.

With age:

• The cheekbone flattens and descends. The fullest point of the cheek ends up lower and closer to the nose.
• The tear trough appears (between the lower eyelid and the cheek), because the cheek that used to fill it has descended and lost volume, and because there is a ligament holding the skin at that point.
• The nasolabial fold (from the nose to the corner of the mouth) becomes more pronounced, because the volume of the cheek has descended and accumulates on the outer side of the fold, while the inner side loses bony support.
• The face may look "wider at the bottom", with weight shifted towards the jaw area.

In practice, this translates into a more tired look and a sadder expression, even at rest, and it is often what leads someone to say "I look tired", without being able to identify why.

The jaw and neck: where the contour is lost

The jawline is one of the features that contributes most to a youthful, defined look, in women and in men. With age, it is lost in several ways at once.

Jowls

The cheek tissues that have descended accumulate beside the chin, just above the jawline. Because there is a ligament anchoring the skin to the jaw in front of this area, a small depression forms between the chin and the jowl (the so-called pre-jowl sulcus). The contour, which was a continuous line, now has an interruption.

Less defined jaw angle

With less bone, less muscle tone and skin with less elasticity, the angle at the back, below the ear, becomes less distinct. The transition between the face and the neck becomes softer and less marked.

The neck

• Fat under the chin (submental), which can exist even in thin people and tends to become more visible with age.
• Platysmal bands, vertical cords that become visible when speaking or tensing the neck.
• Thinner skin with horizontal lines, often with sun damage, because the neck rarely receives sunscreen.

Posture and "tech neck"

There is a lot of discussion about whether looking at your phone with your head tilted accelerates neck lines and loss of contour. The direct scientific evidence is scarce. What is certain is that a posture with the head projected forwards makes the jawline look less defined in photographs and in the mirror, regardless of ageing.

What accelerates loss of contour

Sources: Guyuron et al., 2009; Brincat, 2000; Shaw et al., 2010.

An approximate timeline

Everyone has their own pace, but a typical course is:

• 30 to 40 years: first changes in the midface, more visible tear trough, cheekbones slightly less full.
• 40 to 50 years: more marked nasolabial fold, beginnings of jowls, less sharp jawline.
• 50 years onwards: more evident loss of contour, changes in the neck, greater impact of bone loss, especially in women after the menopause.

What can be done

Because the problem lies in several layers, no single solution fixes everything. It helps to think in three levels.

1. At home: protect and improve the skin

• Sunscreen on the face, neck and décolletage, every day (Hughes et al., 2013). The neck is often forgotten and ages quickly.
• Topical retinoid at night, on the neck too, with gradual adaptation (the skin of the neck is more sensitive).
• Hydration and barrier care.
• Oral health: treating and replacing lost teeth helps preserve the jaw bones.
• Stable weight, not smoking, enough sleep.
• Posture: raising the screen to eye level does not rejuvenate, but avoids a position that accentuates jowls.

What these measures do: they improve the quality, tone and some firmness of the skin, and halt sun damage. What they do not do: they do not restore bone, give back volume or reposition tissues that have descended.

2. In the clinic: firmness and skin quality

• Collagen-stimulating technologies (radiofrequency, focused ultrasound, among others): they can improve skin firmness gradually and moderately, with better results in mild to moderate sagging.
• Peels and microneedling: they act mainly on texture and skin quality.
• Facial massage and drainage: they can temporarily reduce puffiness and give a sense of a more defined face, but the effect on structure has not been demonstrated.

3. Medical treatments: structure and volume

To restore support and contour, the options work on the deeper layers and require medical assessment:

• Hyaluronic acid filler at support points (cheekbones, jaw angle and jawline, chin), to compensate for bone and volume loss.
• Injectable biostimulators, which stimulate collagen production over months.
• Treatments aimed at the neck (submental fat, platysmal bands), depending on the case.
• Surgery (face and neck lift), when there is excess skin and significant descent of the tissues.

A useful rule: support first, surface second. Restoring structure at key points can improve the contour more than treating the area that has "dropped" directly.

At Luxmed, the contour assessment begins by understanding which layers have changed in your face. From there we propose a plan in stages, with skin care and in-clinic firming treatments and, when indicated, referral for medical assessment.

This article is for information purposes and does not replace a medical consultation. The results of any treatment vary from person to person.

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