Orthodontic elastics, often called rubber bands, are small, medical-grade loops that play a distinct role in orthodontic treatment. They are fundamentally different from the ligatures or power chains that hold the main archwire to individual brackets. Elastics are specifically designed to create an inter-arch force, generating controlled, continuous tension between the upper and lower jaws. This force is achieved by stretching the band between specialized hooks or buttons attached to the brackets of opposing teeth. Their primary purpose is not to straighten individual teeth but to correct the overall alignment of the bite.
Correcting Jaw Alignment
The wires and brackets of braces are highly effective at aligning teeth within their respective arches. However, the fixed appliance alone cannot effectively move the entire maxilla or mandible relative to one another. The inter-arch force of elastics applies a directional pull necessary to guide the entire dental arch into a correct relationship, correcting malocclusions or “bad bites.” This continuous force initiates bone remodeling. Where pressure is applied, bone is broken down (resorption), and where tension occurs, new bone grows (apposition), allowing the supporting structure to shift permanently.
Specific Elastic Configurations
Orthodontists prescribe elastics in specific, patterned configurations to target different types of malocclusion.
Common Elastic Configurations
- Class II elastic: Used to correct an overbite, where the upper front teeth overlap the lower teeth. This band stretches from a hook on the upper canine to a hook on a lower molar, moving the upper teeth backward and bringing the lower jaw forward.
- Class III elastic: Addresses an underbite, where the lower jaw protrudes past the upper jaw. This pattern runs from a hook on a lower canine to a hook on an upper molar, moving the lower arch backward while encouraging the upper arch forward.
- Triangle elastics: These vertical configurations use three attachment points to help settle the bite vertically, often closing an open bite.
- Cross elastics: Used to correct a crossbite, applying force across the arch to pull teeth into proper alignment when the upper teeth sit inside the lower teeth.
Practical Use and Patient Responsibility
The success of treatment using orthodontic elastics depends almost entirely on consistent patient wear. Since elastics are removable, patient compliance is a significant factor in the speed and quality of the final result. The prescribed regimen typically requires the elastics to be worn up to 24 hours a day, only being removed for brushing, flossing, and eating. It is important to change the elastics multiple times daily, usually after every meal, because the material quickly loses tension once stretched. Failure to wear elastics consistently causes treatment delays, often prolonging the time spent in braces by months, and can increase discomfort.