01Volume loss in the midface
As the fat pads and bone support in the upper cheek thin out, the cheek sits lower and the fold beside the nose deepens. The fold is the shadow, not the source.
How a doctor tellsA doctor looks at your face from the side and at 45 degrees. If the upper cheek looks flat and the fold softens when the cheek is gently lifted with a finger, volume is a big part of it.
02Sagging skin and soft tissue
With age, skin and the tissue under it loosen and slide down. The fold then looks heavier toward the mouth and often comes with jowls.
How a doctor tellsThe doctor checks skin laxity with a pinch and watches whether the fold continues into a heavier lower face. Laxity points toward tightening or lifting rather than filling.
03Expression and muscle pull
Some people have strong muscles around the mouth and nose. The fold is deep when they smile and almost gone at rest.
How a doctor tellsYou will be asked to relax, then smile. A fold that mostly appears with movement is about expression, which filler does little for.
04Skin quality
Thin, dry or sun-damaged skin creases more easily, so a mild fold looks etched.
How a doctor tellsThe doctor looks at fine lines and texture across the cheeks, not only at the fold itself.
05Your bone structure
A flatter midface or a set-back upper jaw can make the fold visible even in your twenties. This is anatomy, not ageing.
How a doctor tellsIf the fold has always been there in old photos, structure is likely part of it. Injections can soften it, not change it.