Orthodontic elastics, often called rubber bands, are small, removable loops made from a flexible, medical-grade material. Used with fixed braces, they apply a specific, continuous force that brackets and wires alone cannot generate. They connect between points on the upper and lower dental arches, creating tension to guide the teeth and jaw structures into their correct positions.
Why Elastics Are Essential for Bite Correction
Traditional braces primarily align individual teeth within their arches, correcting issues like crowding or spacing. This alignment does not resolve macro-level discrepancies in how the upper and lower jaws fit together. This relationship, known as occlusion or the bite, requires a different mechanical approach. Elastics provide the necessary inter-arch force to achieve this proper fit.
The purpose of elastics is to correct malocclusions, which are misalignments of the dental arches that manifest as overbites, underbites, or crossbites. By spanning the distance between the upper and lower jaws, elastics create reciprocal pressure that encourages the entire jaw structure to move or reorient. This continuous, gentle tension facilitates the movement of teeth, and sometimes the entire jaw, in a way that establishes a healthy, balanced bite. Without the use of elastics, many bite issues would remain uncorrected. The elastics are thus responsible for the final, functional positioning of the teeth and jaws, ensuring a comfortable and efficient chewing relationship.
Common Configurations for Elastic Placement
The placement of elastics is highly customized, designed to target the specific direction of movement needed to correct a patient’s bite issue.
Class II Elastics
The Class II elastic configuration corrects an overbite, where the upper teeth or jaw protrude too far forward relative to the lower teeth. This setup typically involves stretching the elastic from a hook on an upper canine or front tooth area to a hook on a lower molar or back tooth. The resulting force pulls the upper teeth backward and the lower teeth forward, effectively closing the gap between the arches.
Class III Elastics
The Class III elastic pattern addresses an underbite, where the lower jaw or teeth sit forward of the upper teeth. In this configuration, the elastic extends from a lower canine or front tooth hook to an upper molar or back tooth hook. The tension works to retract the lower jaw structure while encouraging the upper jaw to move forward. This opposing force aims to bring the upper teeth in front of the lower teeth, achieving a correct anterior relationship.
Cross-Bite Elastics
Cross-bite elastics correct a lateral misalignment where the upper and lower teeth do not meet correctly side-to-side. These elastics are placed diagonally across the mouth, connecting a hook on the outer (buccal) side of an upper tooth to a hook on the inner (lingual) side of a corresponding lower tooth. This arrangement applies a force that pulls the teeth laterally, into proper alignment. The orthodontist determines the precise size and force of the elastic, ensuring the correct amount of pressure is applied to achieve the prescribed movement.
Practical Guidelines for Wearing and Caring for Elastics
The success of bite correction with elastics is directly tied to a patient’s commitment to wearing them consistently, as the force must be virtually uninterrupted to achieve biological movement. Orthodontists instruct patients to wear elastics for 20 to 24 hours every day, removing them only for eating and brushing. Poor compliance, such as wearing them only at night, significantly slows down treatment progress, potentially adding months to the overall timeline. Any prolonged interruption allows the teeth to drift back toward their original positions.
Elastics lose their elasticity and force throughout the day due to stretching, moisture, and temperature changes. Therefore, they must be changed frequently, usually three to four times per day, such as after every meal and before bed. Always replace a worn elastic with a fresh one to ensure the therapeutic pressure remains consistent. Patients should never attempt to double up elastics to compensate for missed wear time, as this can apply excessive force that may damage the tooth roots or surrounding bone.
Initial soreness in the teeth and jaw is common when first starting elastic wear or after a configuration change, as the teeth begin to move. This discomfort is temporary and usually subsides within a few days of continuous wear. Over-the-counter pain relievers can help manage this initial tenderness, and consistent wear ensures that this soreness does not return. Carrying a supply of fresh elastics is advisable, as they can occasionally break or be lost upon removal, and immediate replacement is necessary to maintain continuous force.