Orthodontic elastics, commonly known as rubber bands, are a frequent and removable component of braces treatment. Made from medical-grade latex or non-latex materials, these small, stretchy bands are placed over the brackets of the upper and lower teeth. While the brackets and wires align the teeth within each arch, elastics perform the specific function of correcting the relationship between the two arches. They are prescribed to create gentle, continuous pressure that moves entire groups of teeth or adjusts the jaw position itself.
The Primary Role of Orthodontic Elastics
The main purpose of orthodontic elastics is to correct the bite relationship, or occlusion, between the upper and lower jaws, a task that braces wires alone cannot accomplish effectively. Braces wires exert force to straighten individual teeth along the dental arch. Elastics, however, are placed across the upper and lower arches to generate inter-jaw force vectors that guide the jaws into a proper alignment.
This targeted force is necessary to address various forms of malocclusion, such as an overbite, underbite, or crossbite. The elastics are typically looped over small hooks on the upper and lower brackets, creating tension. This consistent pull or push works over time to reposition the dental arches so that the teeth meet correctly, facilitating proper chewing function.
Understanding Elastic Classifications and Force
Orthodontic elastics are categorized by the type of bite correction they are intended to achieve, specifically addressing the relationship between the upper and lower jaws. The most common grouping is based on the Angle classification of malocclusion.
Class II elastics are used to correct an overbite, where the upper teeth protrude excessively, by applying force to move the upper teeth backward and the lower teeth forward. Conversely, Class III elastics are prescribed for an underbite, where the lower jaw sits in front of the upper jaw. These elastics are configured to pull the lower teeth backward while encouraging the upper teeth to move forward. A third category, Class I elastics, is used for minor adjustments within the arches, such as closing spaces or correcting a crossbite, often applied in a diagonal or triangular pattern.
Elastics are also precisely graded by size and the force they deliver, which is typically measured in ounces or grams. The diameter of the elastic and its thickness determine the level of force it applies when stretched to the correct distance between the hooks. Orthodontists select a specific size and force—light, medium, or heavy—to ensure the force is gentle yet continuous enough to stimulate bone remodeling and tooth movement without causing tissue damage.
Practical Guidelines for Wearing and Care
For elastics to be effective, they must be worn consistently, typically for 20 to 22 hours per day, which means wearing them while sleeping. The continuous nature of the force allows for the gradual and sustained movement of the teeth and jaw structures. They should only be removed for eating and for brushing and flossing to maintain oral hygiene.
It is important to change the elastics frequently because they lose their elasticity rapidly, often degrading up to 30% of their force within the first few hours of use. Orthodontists advise replacing them at least three to four times a day, such as after every meal, to ensure the necessary therapeutic force is consistently applied. New elastics should be used each time, and patients should avoid wearing two elastics at once unless specifically instructed, as this can apply excessive, uncontrolled force.
Some initial soreness of the teeth is common during the first few days of wearing elastics, indicating that the teeth are beginning to move. This discomfort usually fades as the mouth adjusts to the new pressure. Maintaining consistent wear is the best way to prevent the recurring soreness that happens when elastics are worn intermittently.
Consequences of Not Wearing Elastics
Inconsistent wear of orthodontic elastics is one of the most common reasons treatment may take longer than initially expected. If the elastics are not worn for the prescribed number of hours, the progress made while they were in place can quickly be lost. Teeth have a tendency to move back toward their original positions when the continuous force is removed, effectively stalling treatment.
This failure to maintain consistent pressure can significantly extend the overall time spent in braces, often requiring several extra months to correct the bite. Furthermore, without the specific inter-jaw force provided by the elastics, the bite correction may remain incomplete, leading to a compromised final outcome. A misaligned bite can result in functional issues, such as uneven wear on the teeth or difficulty chewing, which can affect long-term oral health.