archwires

Archwires are flexible metal wires used in fixed orthodontic appliances to move and align teeth. They run through brackets bonded to individual teeth and transmit forces from the brackets to the teeth, guiding three-dimensional tooth movement along the dental arch. Archwires work in conjunction with ligatures or self-ligating brackets to hold the wire in place and to allow adjustments during treatment.

Materials and forms vary. The most common archwires are stainless steel, nickel-titanium (NiTi), and beta-titanium (TMA). NiTi wires exhibit shape memory and superelasticity, delivering light, continuous forces that can adapt to small changes in tooth position, which is advantageous for initial alignment. Stainless steel wires are stiffer and provide robust control for space closure, leveling, and torque management in later stages. Beta-titanium wires offer a balance between rigidity and formability, useful for intermediate and finishing stages.

Wires come in different cross-sections and sizes. Round wires (for alignment and leveling) typically range from about 0.012 to 0.018 inches in diameter, while rectangular wires (for three-dimensional control of tooth position) often measure around 0.019 x 0.025 inches or 0.018 x 0.025 inches. The choice of wire depends on treatment goals, stage of treatment, and individual tooth biology. Wires may be preformed or bent (torqued) in the clinic to achieve desired tooth movements, and they are secured to brackets with elastomeric ligatures or by using self-ligating brackets.

Archwires are selected and exchanged throughout treatment to progressively guide the dentition toward the planned occlusion and aesthetic outcome.