Why expression lines deepen over time

Every expression creases the skin. Smiling, squinting, frowning, raising the brows — each one folds the surface in the same place, thousands of times a year. In younger skin the fold releases completely and leaves nothing behind.

What changes is not the movement. It is the skin’s ability to recover from it.

Dynamic lines and static lines

A line that appears only during movement is a dynamic line. A line still visible when the face is completely at rest is a static line. The second is the first, repeated for long enough that the skin stops springing back.

The crossover is gradual and most people cannot date it. They simply notice one morning that something that used to come and go now stays.

Why some lines deepen faster than others

Lines do not all behave the same way, and the variation is not random:

• How strong the movement is, and how often. A brow that lifts constantly creases more than one that does not.
• Skin quality. Thin, dry or sun-damaged skin folds more readily and recovers less well.
• Genetics. Both the anatomy underneath and the habitual patterns of expression run in families.
• Sun, smoking and alcohol. All three break down the collagen and elastin that let skin recover.
• Unconscious habits. Brow raising while concentrating, or clenching while driving, are done for hours without being noticed.

This is why two people the same age can have completely different patterns. It is rarely about how old someone is.

Movement ageing and structural ageing are not the same thing

It helps to separate them, because they need different answers.

Movement ageing is what repeated expression does to the surface. Structural ageing is what happens underneath — bone remodelling, fat compartments shifting, skin thinning. I have written about that separately in why faces lose volume.

They happen at the same time and they compound. Someone can have excellent skin and still look tired, because the support beneath it has changed. Someone else can have good structure and deep lines from twenty years of squinting into the light. Working out which is doing the most is most of the assessment.

What is actually within your control

Less than the internet suggests, but not nothing:

• Sun protection. Comfortably the most effective thing, and the one most people are inconsistent about.
• Sunglasses. Not vanity — they stop you squinting, which is the movement itself.
• Not smoking. It damages collagen and the small vessels that supply the skin.
• Looking after the skin over time. Slow, unglamorous, and the part most often abandoned before it shows.

None of this stops lines forming. It changes the pace, and it improves the material anyone is working with later.

What I look at

I watch the face at rest and in movement, because a line that only appears in animation is a different problem from one that is there constantly. I look at where light falls. I ask about sun exposure, sleep and stress, because they show.

Then we talk about whether anything is worth doing. Options are discussed at the appointment rather than decided beforehand, and there is no expectation that you proceed. Sometimes the honest answer is that good sun protection would serve you better than anything I could offer, and I will say so.

This article explains a process. It is general information, not clinical advice, and it is not a recommendation for any particular treatment. Whether anything is suitable for you is a matter for individual assessment.