What Are Smile Lines?
Smile lines typically include:
- Nasolabial folds – the lines that run from the sides of the nose to the corners of the mouth
- Marionette lines – the lines that extend downward from the corners of the mouth toward the chin
These lines deepen due to:
- Loss of midface volume
- Descent of facial tissues
- Repetitive facial movement
- Changes in skin elasticity
Treating smile lines effectively requires understanding why they form—not just where they appear.


