The efficacy principle of 4D line carving is different in different regions, but the principle is the same. PDO line implanted in the skin promotes skin reaction, then causes a series of repairs, and at the same time promotes the production of collagen, accelerates our metabolic process, and makes our skin more delicate and smooth.

4D engraving and thread lifting is also called 4D embedding and thread lifting, and it is also called FTL in North Korea. Thin thread containing PDO (poly (p-dioxanone)) is used to bury the skin, and PDO thread is used to lift the face. In China, Hong Kong and Taiwan, it is called "Reverse Time Line, Frozen Age Line, 3D-V Venus Line, 4D Full Face Pull, 4D Buried Thread Pull".