A Quad Helix is an orthodontic appliance for the upper teeth that is cemented in the mouth

Mouth

The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....

. It is attached to the molar

Molar (tooth)

Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....

s by 2 bands and has Two or four active helix

Helix

A helix is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helixes are coil springs and the handrails of spiral staircases. A "filled-in" helix – for...

 springs

Spring (device)

A spring is an elastic object used to store mechanical energy. Springs are usually made out of spring steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication...

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 mil stainless steel wire and is primarily indicated in mixed dentition, cleft patients and those that have performed the act of thumbsucking. 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.