Running loops have been used in mandibular second premolar extraction treatment instead of cherry or shoehorn closing loops in the Tweed technique. They can also be used when molar extraction patterns are unusual or if molars are missing or hopeless, or have extensive restorations. A running loop archwire is usually made of 0.018 x 0.025-in stainless steel, with a helical loop 5 mm mesial to the buccal tube. The effective tipback is usually about 20 degrees to 30 degrees to upright molars, and a slight toe-in is necessary to prevent mesiolingual rotation. As the extraction space closes, the distance between the running loop and the buccal tube is shortened. Then a helical loop can be moved mesially to maintain the distance and the force between them by simple archwire manipulation. Consequently, the extraction space can be closed with 1 running loop archwire after initial leveling.