Final answer:
Stainless steel archwires are used in the final stages of orthodontic treatment for detailed teeth alignment due to their malleability and ductility, applying a force towards the back of the mouth.
Step-by-step explanation:
The type of archwire mentioned is most likely a stainless steel wire, which is commonly used in the latter stages of orthodontic treatment. The quality of being able to retain bends well makes it an excellent detailing wire, which is crucial for the fine-tuning of teeth alignment. Stainless steel wires are both malleable and ductile, meaning they can be easily shaped and bent without breaking, as well as drawn into thin wires, ideal qualities for applying precise forces to teeth as depicted in figures showing the tension applied to a protruding tooth by the wire in braces. These wires apply a total force, Fapp, that is directed towards the back of the mouth, helping to realign teeth into their desired positions.