We often think expression lines are wrinkles, but that is not true.
Expression lines are the visible muscle movements of a normal face – such as “laugh lines” at the corners of our eyes, concentration lines between the eyebrows, and smile lines on cheeks.
Wrinkles are lines that persist as furrows and creases even with relaxed facial muscles, ie, no expression. Untreated habitual expression lines like a constant frown can deepen, and crease into a static wrinkle as collagen and fat are lost from the skin.
In the same way, even a deep set wrinkle, with correct treatment can reduce into a fine line making it much less apparent.