Orthodontic Tooth Movement and Bone Remodeling
When you get braces, you’re probably focused mostly on the part of your smile that you see. That is, the “crown” portion above the gum lines. However, with orthodontic treatment you need to understand basic root anatomy to visualize how braces work.
Tooth roots are approximately twice the length of the crown portion that’s visible in your mouth. Each root is surrounded by thousands of tiny ligaments that attach the tooth to the surrounding structures, including gingiva (gums) and bone. The ligaments are slightly stretchy, allowing the tooth to have a microscopic amount of flex to it.
When we use braces to put pressure on teeth from a specific direction, those fibers and ligaments respond. The next thing that happens is what we call bone remodeling. Essentially, when bone remodeling occurs, the bone that the tooth is being pushed towards (the direction the braces are moving your tooth) starts to resorb, or shrink away. At the same time, the bone that your tooth is moving away from will start to add new bone to it, keeping up with the movement of the root. As the ligaments are slightly stretched away, the bone follows it.
We call this process bone remodeling. It’s what makes it possible for braces to work and for us to safely give our orthodontic patients straighter smiles.
Bone remodeling occurs at a specific rate. It’s not a process that you can rush. If your orthodontist were to move your teeth too quickly with braces, it could actually cause permanent long-term damage to your smile, including resorption of your tooth roots. When root resorption occurs, the length of the root shrinks and the tooth is less stable. In severe circumstances, the tooth could die, become mobile on a long-term basis, or even fall out. That’s why it’s important to see an Orthodontist you can trust.
Parts of Braces and How They Work
So how do braces work when they can only attach to certain parts of your teeth? Although it’s what’s going on around your tooth roots that’s actually aligning your smile, the braces themselves attach to the crown. And in most cases, the appliances are only bonded to one side. How do they move the tooth overall?
Most traditional braces are made up of these important parts:
Brackets — The small, square-shaped appliances bonded directly to the front of your teeth are called brackets. A bracket can be made out of metal or tooth-colored ceramic that blends in with your smile. There is room on the front of the bracket for an archwire to fit down into it. Some even have small trap doors that clip over the wire so that it can “glide” between the brackets.
Archwires — An archwire is the “U” shaped metal band that spans the entire width of the upper or lower arch of teeth. It clips into the brackets or is held onto them with small ligatures (made of metal or a colored rubber band.) The archwire holds a consistent shape, applying pressure across the entire smile so that teeth are encouraged to comply with the curvature of the wire. Orthodontists use varying widths of archwires, depending on how much force is needed.
Springs — If you need extra room between teeth, orthodontists will sometimes use small metal springs between the brackets of the adjacent teeth. The spring pushes open, applying pressure against each of the teeth next to it, helping widen the gap.
Note: Springs are used for situations where there isn’t enough room for a tooth to properly fit between two teeth. For example, if a baby tooth falls out prematurely or has to be extracted because of an infection, the adjacent teeth might start to drift inwards before the adult tooth can erupt into the space. A spring creates extra room so that the adult tooth isn’t impacted.
Rubber Bands — Temporary bands are sometimes used to hook the upper arch to the lower arch, adding extra force when necessary. Rubber bands or elastics come in various strengths and are usually only worn for specific lengths of time.
Other Appliances — Sometimes we’ll briefly use other appliances like expanders, Herbst appliances, lingual arches, or other aids to move teeth. Usually, it’s because there’s a skeletal issue where the bone inside of and around the mouth needs to be adjusted. We call this process orthopedic correction. It might be encouraging a healthier jaw shape and position, or widening the arches so that there’s room for all of the teeth to fit in place.
How Do Braces Work for Children vs Adults?
The biggest difference in how braces work for children vs. adults is that the younger a person is, the quicker they tend to respond to growth modification and tooth movement. In young patients, their mouths are still developing; therefore, it’s possible to alter the course of their jaw growth so that more severe tooth alignment or jaw issues can be avoided in the future.
In adults, the jaws are already completely developed. As such, there might be less opportunity to correct jaw positioning with braces. However, Orthodontists like Dr. Cohen can still straighten the teeth with braces, no matter how mature the patient is!
Are Braces Right for You?
Contact us to find out which type of braces is best for your smile’s needs. Call Braces Haven today for a personalized consultation and honest opinion about your smile’s future!