What this site is for
This is patient education about the fold beside the mouth, published by Chongqing West District Hospital, a tertiary general hospital in Jiulongpo District, Chongqing. It is a concern guide rather than a procedure page: it answers what is actually folding, whether it needs treatment, and which of several paths applies. The operations themselves, and the anatomy they work on, are explained on the face hub and on Dr. Mao’s own site, and repeating them here would help nobody.
The distinction the site is built on
The fold is usually volume loss, tissue descent and muscle pull acting together. They are answered in different ways: volume by staged additions, descent by a lift, and muscle pull by reducing the pull. Naming which dominates is most of the decision. The second distinction is about the area itself, because the lower face is where repeated filler accumulates most visibly over years, which is why small staged steps are preferred to a large correction and why the total used over the years matters more than any single treatment.
What it deliberately does not do
It does not name products or brands, quote prices or dosages, or promise a result. It does not present filler as a way to lift tissue that has descended, or a device as a substitute for a lift where a lift is the honest answer. It does not describe surgical technique, because that belongs to the pages that cover the surgery. And it does not treat a mouth corner that has dropped suddenly, or one-sided weakness or numbness, as an appearance problem at any point.
The limits of a website
Nothing here can tell you which of the three mechanisms is producing your own fold. That requires an examination of the face at rest and in movement, of where the tissue above the fold now sits, of the profile and the bite, and of what has been placed in the area before. Reading this site cannot substitute for that, and a plan made from a website alone is a plan made without information.