Subcision is a procedure which releases scars that have become stuck to the deeper tissues and bound down. When a scar forms, new collagen is produced.

Scar collagen is not as supple or as neatly laid as normal collagen. This new collagen can stretch from the scar to the deeper tissues, like a web, and pull the scar down.
This makes the scar look more indented and causes shadows, divots and pits. Breaking these connections helps to lift the scar back up.