Folds of bitterness
The bitterness folds, sometimes known as marionette lines, are a common, natural sign of aging that appear around the mouth and chin.
With age, the underlying dermal tissue loses volume and the elasticity of the skin is reduced leading to the overall sagging of the facial skin and the formation of folds, wrinkles, and fine lines, particularly on the lower part of the face.
The bitterness folds vary in depth and start from the corners of the mouth and extend down towards the chin. In some cases, the bitterness folds are straighter and in others they bend outwards. These wrinkles are quite subtle, to such a point that it can be difficult to draw the exact line. They extend from the nasolabial fold (between the nose and mouth), with which they are often confused.
They result in a discontented, bitter appearance, as the unattractive name suggests. Not only do these wrinkles reflect a negative emotion, but they create a shadow between the chin and the cheek: they are often the source of sagging jowls and, thus blurred, ill-defined chin contours.
Due to an optical effect, these vertical lines extending from the corners of the mouth also give the impression that you are frowning or scowling when it is not the case.
Generally speaking, the bitterness folds begin to develop at the age of 40 in both men and women. Barely visible to begin with, they change at varying rates depending on the quality of the skin or genetics and other external factors such as lifestyle, smoking, or excessive consumption of alcohol.