Braces: Their Parts And Use
Braces, also known as fixed orthodontic appliances, are used to fix a wide variety of dental problems, for example fixing teeth which are crooked or that stick out. The components that make up braces include brackets, molar bands, arch wires, either elastomeric or steel ligatures, and auxiliary components such as power chain, active coil and intermaxillary elastics.
Orthodontic brackets are secured to the teeth using bonding cement. These brackets have built-in features to control the movement and angle of the teeth. One of these features is a slot where the dentist will place the arch wire, allowing for controlled movement of the teeth. Tie wings are located at the corners of the bracket and stand out beyond its base. This is where the dentist will attach the elastomeric or stainless steel ligatures which will secure the wire to the bracket.
You may notice that some brackets contain a hook on them. These are used to attach auxiliary components such as coil springs and elastics to the appliance. These are usually on brackets placed on the canine and premolar teeth.
Molar bands are used for teeth that are difficult to treat with brackets. This may be the case for teeth that are partially erupted and have not fully grown above the gum line, when other appliances such as headgear are required, and on teeth with large metal restorations.
Molar bands have a slot where the arch wire is placed, connecting them to the rest of the brackets on the teeth. Some may also have a slightly larger tube for the placement of headgear. Once the appropriate sized band is selected, it is cemented in place.
Once orthodontic brackets are cemented onto the teeth, an arch wire must be placed within the slots of the brackets to begin treatment. Arch wires come in various shapes such as round, square and rectangular and in various materials such as nickel titanium, stainless steel and beta titanium. The choice of which particular wire to use is largely dependent on the stage of treatment and the type of tooth movement that is required.
Once the arch wire is positioned within the slot of the orthodontic bracket, it must be secured in place with either an elastomeric or stainless steel ligature. Some brackets, known as self-ligating brackets, do not require ligatures.
Elastomeric ligatures are small diameter elastic bands that are stretched over the tie wings of the orthodontic bracket, attaching the wire to the bracket. These elastomeric ligatures come in a variety of colours and are changed at every visit.
Another option for securing the arch wire into the bracket slot is a stainless steel ligature. These ligatures are placed around the tie wings of the bracket and the ends are twisted multiple times until firmly secured. The wire is then cut and the end of the steel tie is tucked under the arch wire to avoid irritating the inner lip or cheek.
There are a few other items that your dentist may use in your orthodontic treatment. These auxiliary components include a power chain, intermaxillary elastics, and active or open coil spring.
A power chain is an elastomeric chain primarily used for the closure of space but can also be used for other purposes, such as rotating a tooth. When using a power chain, the teeth on either side of the space to be closed will be secured with stainless steel ligatures and the power chain stretched over the space.
Intermaxillary elastics are elastic bands used to apply a force between the upper and lower jaws to move the teeth, and to some extent, the jaws into place. Configuration of these elastics will depend on the treatment plan.
An active or open coil spring is another auxiliary component, which is used to open space within the jaw. The dentist will prepare the coil and then compress it between the teeth to be treated, slowly opening space between the teeth.
Braces are the most commonly used orthodontic appliance. They allow for the controlled movement of teeth in three dimensions. This appliance, along with the use of auxiliaries, allows for a wide range of treatment options to straighten your teeth and adjust your bite, therefore improving the function and aesthetics of your smile.