PDO (Polydioxanone) thread is a thread with no cones, thus no damage to the tissue. This has been widely used in medicine as subcutaneous sutures, and thus it is very safe.pdo thread (Cog/Tornado/Mono/Screw) . Mono is most representative and known widely. Most often used for skin elasticity through self-stimulation of cells. There is no interrupt in a daily life even right after the procedure and he efficiency becomes even more increased with age. In addition, there is no side effect or worries about removal operation because it will be fully dissolved in the body after about 1 year.