Physics Behind Orthodontic Rubber Bands – A Brief Explanation

Elastics in Orthodontics

Orthodontic treatment is an increasingly innovative specialization of dental medicine. The science behind orthodontics includes software for modeling and identification of cases, materials science that rests upon nanotechnology to produce discrete and effective compounds, and a handful of other areas of knowledge and its applications.

Notwithstanding, the most crucial of all areas is Biomechanics. This might sound a bit overwhelming, so to ensure we have your attention, we will name it the “strain exerted to teeth to reposition them to their natural place.”

So, to stress teeth forcing them to move, Orthodontists calculate the level of force that needs to be applied. Too much stress might cause a tooth to get loose and little stress might produce little to no results. 

Orthodontics is all about physics. So, first, orthodontists determine a constant but effective strain that, little by little, gets teeth to move. To do so, orthodontists use several devices, artifacts, and peripherals. 

Braces and Clear Alignment devices are the most common orthodontic devices used to align teeth. Depending on each case, Peripherals complement the action of devices and help them obtain effective results.        

This article addresses the importance of elastics in orthodontic treatment, the types of elastics used and their categories, and the measures to reduce discomfort and pain for patients wearing braces and elastics.

What Do Orthodontic Rubber Bands Do?

First, not all treatments require the use of elastic rubber bands. As we previously stated, Orthodontists evaluate the levels of stress each case requires in advance. In some cases, patients use braces with no rubber bands, and once teeth advance to a specific point, the specialist continues treatment, including rubber bands. 

Orthodontists work in stages. This is why patients must constantly attend checkups and adjustment visits. Adjustments serve to shape the wires little by little to the final position. Wires serve to mold teeth with each adjustment slowly. Doing so at once would be impossible and harmful. 

Brackets serve to hold the wires that exert strain over teeth. This is because wires try to get to their former position, pulling teeth. However, some malocclusion cases require moving teeth at diverse angles and repositioning the jaws. Therefore, rubber bands are complementary peripherals that apply extra stress. 

In some cases, rubber bands are placed in the brackets to tightly hold the wires, securing them and forcing them into position. Some jaw repositioning cases require the use of elastics that are attached to brackets with special hooks. Pressure at each extreme forces the jaw to slowly move. 

What Are the Types of Elastics in Orthodontics?

Several types of elastics serve different functions and according to different malocclusion cases. First, we briefly described how they function by moving teeth and repositioning the jaw. Here we depict a more specific approach to cases and rubber band classes.

Strain Force

Force in physics is an external agent (braces, wires, and rubber bands) capable of changing the state of rest or motion of a particular body (teeth). Force has a magnitude and a direction. When it comes to magnitude, force ranges from light to heavy. Rubber bands are similarly categorized. Depending on the force (strain) they are capable of applying.

  • Light
  • Medium
  • Heavy

Diameter Size

There are different rubber band diameters; each depends on how long they need to stretch. In some cases, some brackets have hooks attached to them. These hooks locate in two teeth. 

A bracket has a hook affixed and cemented to a tooth in the mandible or lower jaw, and the other in a tooth in the maxilla or upper jaw. Consequently, the rubber band must extend from one jaw to the other. 

Some other rubber bands are tinny as a bracket and inserted in a little gap between the bracket and the wire.

Utility

We have previously introduced two types of rubber bands and their uses. Incidentally, we introduced a couple of elastic rubber band uses. Here we define them according to some malocclusion cases:

Class I: 

Sometimes a gap between teeth needs to be closed. In those cases, the hooks are at the extremes on each tooth. The elastic rubber band is then attached to each hook.

Class II: 

Overbite is a gap between the front upper and lower teeth at biting. A rubber band connects teeth on the upper jaw and molars (located in the back) of the lower jaw. This condition is often known as an overbite.

Class III: 

An underbite is a condition that is seemingly different from an overbite. The lower jaw extends further to the front. Therefore, the rubber band connects teeth on the lower jaw with molars on the upper jaw.

Vertical: 

Openbite is a severe malocclusion in which front upper teeth form an angle and do not meet with lower front teeth at the bite. Therefore, rubber bands are attached to brackets on the upper teeth and the teeth below to correct the angle. 

Cross: 

The jaws are not symmetrically aligned, and some teeth fit, and others don’t when meeting at biting. This is called a crossbite. Rubber bands connect the upper and lower jaw teeth that do not meet at biting.

What to Do About Pain Caused by Elastic Bands?

Getting rubber bands for the first time is annoying. Sometimes patients experience pain, and this is normal. In this article’s first part, we mentioned the physics of moving teeth and how rubber bands help exert extra pressure over teeth. 

If you feel pain, it is ok to get some ice or cold water where it hurts, and you might also take some over-the-counter pain relief medicine; just ask your Orthodontist before doing so. However, having prolongated pain is not normal, so, in such a case, you should call your Orthodontic specialist to get an evaluation and find the cause of the problem.