The two by four appliance: a versatile appliance.

The 2 x 4 appliance comprises bonds on the maxillary incisors, bands on the first permanent maxillary molars and a continuous archwire. The appliance is used in the early mixed dentition for treatment of both anterior crossbites and alignment of ectopic incisors. Four cases using this appliance are presented. This appliance offers many advantages over alternative techniques as it provides complete control of anterior tooth position, is extremely well tolerated, requires no adjustment by the patient and allows accurate and rapid positioning of the teeth.