Orthodontic braces are appliances designed to apply controlled forces to teeth, guiding them into new positions for proper alignment and function. Braces rely on a combination of brackets, a flexible archwire, and various auxiliary components to achieve the desired movement. The question of whether all braces require rubber bands has a nuanced answer, as the term “rubber bands” refers to two distinct elastic components used for different purposes during treatment. A patient’s specific needs dictate which, if any, of these elastic components will be incorporated into the treatment plan.
The Difference Between Ligatures and Inter-arch Elastics
The two types of elastic components used in orthodontics serve separate mechanical roles and are often confused. The first type is the ligature, a small, typically colorful or clear elastic O-ring that encircles the wings of a traditional bracket. The sole function of a ligature is to securely hold the archwire within the bracket’s horizontal slot, ensuring the wire’s tension is transferred to the tooth. Ligatures are passive components; the orthodontist places and removes them during adjustment appointments, and the patient is not responsible for their daily management.
The second type is the inter-arch elastic, the larger rubber band that patients place themselves. These elastics span the distance between the upper and lower dental arches, connecting hooks on opposing brackets. Unlike ligatures, which work within a single arch, inter-arch elastics are active components that generate force between the jaws. The patient must consistently wear these bands for the prescribed number of hours each day, typically 20 to 24 hours, for them to effectively move the upper and lower arches relative to each other.
Why Inter-arch Elastics Are Prescribed
Inter-arch elastics are not used for straightening individual teeth, but for correcting a malocclusion, or a poor relationship between the two jaws. Braces alone are efficient at leveling and aligning teeth within each arch, but they cannot effectively reposition the upper or lower jaw relative to one another. The elastics apply a continuous, gentle force that helps achieve the final, correct bite relationship.
The most common reasons for prescribing these elastics are to correct Class II and Class III discrepancies. A Class II malocclusion (overbite) requires elastics to pull the upper teeth backward and the lower teeth forward to align the jaws correctly. Conversely, a Class III malocclusion (underbite) requires elastics configured to pull the upper teeth forward and the lower teeth backward.
These elastics can be configured in multiple patterns, such as diagonal setups for anteroposterior correction or triangular boxes for vertical control, helping to address issues like open bites or deep bites. The pressure exerted by the elastics acts on the teeth and the underlying bone structure, facilitating necessary skeletal movement. Because success depends entirely on the constant application of force, consistent daily wear is paramount for achieving the desired treatment outcome.
Braces Systems That Do Not Use Ligatures
While traditional braces require elastic ligatures to secure the archwire, modern systems known as self-ligating braces eliminate this component. Self-ligating braces feature a specialized mechanical door or clip built directly into the bracket itself. This integrated mechanism secures the archwire without the need for the small elastic O-rings or metal ties used in conventional brackets.
The design of self-ligating brackets often results in less friction between the archwire and the bracket, which may allow for gentler forces and fewer adjustment appointments. The absence of elastic ligatures also removes a common area where food particles and plaque can accumulate, simplifying oral hygiene. Patients with self-ligating braces may still be required to wear the larger inter-arch elastics. If the treatment plan requires correction of a Class II or Class III bite discrepancy, the self-ligating system incorporates small hooks to accommodate the necessary inter-arch elastics for jaw alignment.