What Exactly Does An Expander Do?

What exactly does an expander do?

What is an expander: An orthodontic expander is a device that takes a narrow arch of teeth (upper or lower, or both) and widens it to the right size.  Indications that an arch is narrow can include dental crossbites (situations where the upper teeth are inside the lower teeth; the opposite of the correct relationship), teeth angled improperly in bone, inadequate space for permanent teeth to come into the mouth (instead, they’re getting stuck up in the gums due to lack of space), difficulty breathing through the nose (which could include snoring, or breathing through the mouth when sleeping), among others.

Oftentimes, two or more of these conditions present simultaneously. In all cases, it’s important to expand to create enough space for teeth to grow in as well as the correct biting relationship to allow jaw growth to continue normally.

You can think of expansion as laying the groundwork for what will eventually be a beautiful smile. Essentially, we’re creating needed space in a mouth, when not enough space is present. Expansion alone does not create beautiful teeth, it sets the stage for braces or aligners to do their work. You can think of expansion as the initial stages of building a house. 

Before the siding can be put on, paint can be applied or a family portrait be placed perfectly on the mantle, the site must be graded, the foundation must be poured and the walls must be framed. Without these non-esthetic but critically important preliminary steps, an amazing home would never be built. The same is true with a smile. For people with narrow jaws, expansion is the critical preliminary piece that paves the way to a beautiful and healthy smile.

Why now?

Timing of expansion: Why do orthodontists always want to expand kids so early? When I recommend early expansion (ages 7-10) there are two key motivating factors: First of all, expansion has to be done when a patient’s jaws are still growing. Jaw growth finishes completely at ages 11-12, depending on the individual. As a patient approaches the end of jaw growth, the effectiveness of expansion starts to decrease. 7-10 years old is the “sweet spot” where we can get the best result based on biology alone. 

Secondly, the ages of 7-12 are when all the permanent teeth grow into the mouth. When a patient has a narrow jaw, it is most effective to “get ahead” of tooth growth by making adequately sized “parking spots” for teeth to fit into, before they attempt to grow in. The alternative to early expansion in these cases is to essentially wait until everything gets stuck up in the gums, and then try to unravel a huge mess! Getting ahead of the issue always creates a smoother experience for the patient, as well as a better final result.

I think of jaw expansion in kids almost like a golden ticket. If this minimally invasive procedure is done early in life, jaws grow normally, teeth grow in appropriately, and eventual smile esthetics are maximized. If this critical age of 12 is crossed over without appropriate intervention, there is a significantly greater chance that the patient will need extractions of permanent teeth or jaw surgery later in life.  All this, and the final result still will likely not be as good as if expansion had been performed in early adolescence. All in all, I’m grateful that we have this amazing tool in our toolbox to make such dramatic improvements in our young patients’ lives.