Final answer:
The most common attachment for fixed appliances such as braces is brackets, which hold arch wires that apply pressure and move the teeth into position.
Step-by-step explanation:
The most common type of attachment for fixed appliances in orthodontics is brackets. These are small squares that are bonded directly to the front of each tooth with a special dental bonding agent. Brackets act as handles to hold the arch wires that move the teeth. The arch wires are then fitted into the brackets and adjusted to apply pressure to the teeth, gently moving them into the correct position over time.
Bands are also used sometimes, which are rings that are fitted to the teeth, but brackets are more prevalent for direct tooth attachment. Tubes may be a part of the braces but serve the purpose of housing the ends of the wires, and wires are the component that applies force, propelled by the tension from brackets.