Three palatal arches used to correct posterior dental crossbites.

OBJECTIVE

To assess the force, resilience, and elasticity modulus produced by the Coffin appliance, "W" arch, and quad-helix made with 0.032-inch and 0.036-inch stainless steel wire.

MATERIALS AND METHODS

Two groups of 15 arches were made as Coffin appliances, two groups of 15 arches were made as "W" arches, and two groups of 15 arches were made as quad-helices. One group of each appliance was formed in 0.032-inch and one group in 0.036-inch stainless steel wire. All arches (6 groups of 15 each) were submitted to compression trials in the mechanical testing machine EMIC DL-10000, simulating 5-, 8-, 10-, and 12-mm activation. The force and resilience means received a one-way ANOVA statistical analysis.

RESULTS

The results showed that the mechanical properties depended on the shape of the appliance, the diameter of the wire used, and the amount of activation.

CONCLUSIONS

The three appliances assessed produce appropriate forces for orthodontic treatment as long as they are correctly planned during clinical application.