Almost everyone gets to wear elastics at some point in their orthodontic treatment. Elastics are used for an extremely wide variety of reasons and they are one of the most versatile auxiliaries used in treatment. The main reason they are used is to adjust the bite. Because bites can be off in so many ways, the elastics need to be worn in many different ways depending on how the bite needs to be changed as it is being fixed.
Usually the elastics work between the upper and lower teeth and pit one arch against the other to affect a front-to-back relationship change in the overbite and the mesh of the side teeth. The ways elastics can be worn are divided into 3 classifications and a vertical component can be added to the classifications. The classifications are listed as Class I, Class II and Class III elastics based on the front-to-back force vector and how it affects the overbite. These classifications are in reference to and in harmony with the main way malocclusions are classified. Malocclusions are listed as being Class I, Class II and Class III. Class II elastics have an anterior-posterior pull that corrects a Class II malocclusion, and Class III elastics have an anterior-posterior pull that corrects a Class III malocclusion.
To understand what this means, we need to understand the differences between the malocclusion types. A Class I malocclusion will generally have a normal amount of overbite and the jaws will be lined up in a normal fashion. In a Class I malocclusion the anterior-posterior relationship is considered normal so no change is indicated. A Class I elastic therefore does not change the front-to-back bite relationship as it is active in the same arch and pits the front teeth against the back teeth to close space in that arch of teeth.
A Class II malocclusion is characterized by too much overbite. The upper front teeth protrude ahead of the lower front teeth and the lower jaw is most often recessive and lags behind the normal upper jaw position. The bite on the sides has the upper teeth biting in front of the lower rather than behind in the correct mesh. Class II elastics are hooked from the upper front side teeth to the lower back teeth and pull the lower forward and the upper backwards. As the front teeth move back and the bottom teeth move forward, the overbite reduces. This is how Class II elastics correct a Class II malocclusion.
A Class III malocclusion is characterized by an underbite. The upper front teeth bite behind the lower front teeth and the lower jaw has grown stronger than the upper jaw which is often recessive and lags behind the stronger growing lower jaw position. The bite on the sides has the upper teeth biting behind the lower teeth as they would in the correct mesh, except they are biting one tooth too far back. Class III elastics are hooked from the lower front side teeth to the upper back teeth and pull the upper forward and the lower backwards. As the front teeth move forward and the bottom teeth move backward, the underbite reduces and eventually becomes a normal overbite. This is how Class III elastics correct a Class III malocclusion.
Elastics can perform a multitude of other functions in addition to correcting the bite. The braces and the wires will straighten the teeth, but it is the elastics that make them work to adjust the bite. The braces and wires by themselves can do very little to make adjustments to the bite. Because the bite can be off as a whole, as well as an individual tooth can be out of position and not biting properly, how the elastics are worn will vary greatly, depending on the changes that need to be made. It is impossible to discuss every way the elastics can be worn to fix the bite because of the complexity of the potential problems faced in orthodontic treatment.
In order to be effective in changing the bite, elastics must be worn constantly and consistently. This means that elastics should be worn at least 21-22 hours a day, every day, with no time off for good behavior or any vacation time. The teeth want to rebound or go back to where they were way faster than they want to move in the desired direction. Constant force for a long time is required to achieve the results you are looking for. It is similar to swimming upstream. You have to constantly swim to make any progress, and if you stop, you just float downstream and lose the progress you made, and you always float downstream faster than you can swim upstream.
Elastics are an integral and very important part of treatment. Elastic wear and their effectiveness is thought to be the single greatest factor in determining how fast, or how slow, treatment progresses and when you get your braces off. If you like your braces and don’t want to get done or complete your treatment in a reasonable time, just don’t wear your elastics….you’ll be in treatment forever and never get the bite corrected. If you want to speed up your treatment, wear your elastics as prescribed and do it constantly and consistently!
Changing the bite and correcting either a Class II or a Class III malocclusion is no easy task. It takes diligent consistent and constant elastic wear, but in the end, the new fabulous smile is totally worth the effort! The pain and the struggle is temporary, but your beautiful smile will last your whole lifetime! Just don’t forget to wear your retainers.