
Smile lines form where the cheeks meet the mouth and are heavily influenced by facial movement and midface support. Repeated smiling and expression gradually crease the skin, while age-related collagen loss and volume changes in the cheeks allow folds to deepen.
As structural support diminishes, these lines can remain visible even at rest. Genetics, sun exposure, and skin quality also play a role. For many, pronounced smile lines can create a tired or heavy appearance that doesn’t match how they feel.