Quad-helix is an orthodontic appliance for the upper teeth that is cemented in the mouth. It is attached to the molars by 2 bands and has two or four active helix springs that widen the arch of the mouth to make room for crowded teeth, or correct a posterior cross-bite, where lower teeth are buccal (outer) than upper teeth. It is usually made from 38 mm stainless steel wire and is primarily indicated in mixed dentition, cleft patients and those that have performed the act of thumb sucking. A variety of this appliance is inserted into attachments that are welded to the bands. In this way the orthodontist can adjust the appliance without removing the bands.