Nasolabial folds, also known as laughter lines, are wrinkles that typically develop in old age between the sides of the nose and the corners of the mouth. The main cause of nasolabial folds is sagging in the central part of the face and the cumulative muscle activity generated by movements due to eating, drinking, and laughing.
Nasolabial folds are treated with fillers injected under the skin by a doctor using very fine needles. Treatment usually focuses on the sagging central part of the face, which makes the nasolabial folds disappear.
Initial results can usually be seen after two or three days. The maximum effect develops five to six weeks after the injection.