Is this space normal?

Over the past couple of decades there has been a shift in orthodontic treatment from extracting teeth to expanding the dental arches when crowding is present. Expanders work great, but there are some temporary side effects that can catch parents by surprise. One of those being the opening and eventual closing of a gap between the front teeth.

 

The palate, or roof of the mouth, is made up of two bones joined together in the center by what is called the suture. When a patient is young, this suture is made of stretchable cartilage, and is the area where growth takes place. Expanders take advantage of the still pliable growth plate if they are used before it becomes fused. One sign that the expander has actually moved the two halves of the palate apart is the appearance of a space between the front teeth. The central incisors (2 front teeth) are located on different sides of the growth plate and they spread apart as the palate is expanded. The result is a visible gap between the teeth. This gap is normal and a desired consequence of expansion.

Once the expander has provided the desired amount of expansion, the orthodontist will typically leave it in place for approximately 8-10 weeks, to hold the two halves of the palate apart while new bone develops between them.

During this stabilizing period, the gap created during the expansion tends to close on its own. This happens slowly over time, but it surprises many parents the first time they notice it is smaller or gone altogether. Understandably, many parents call our office worried that the expansion has slipped and that the benefits achieved during the activation have been lost, however, this is not the case.

During palatal expansion, two forces are present on the teeth. The force created by the expander pushes the palate apart and a gap appears between the teeth. At the same time, an opposite force produced by the gum tissues is active on the teeth. Just like other soft tissues in the body, the gums are elastic. As the expander pushes outward, the gum tissue pulls the teeth back together. This can be observed by comparing the size of the gap between the teeth with the amount of expansion visible on the expander. Rarely will the size of the gap between the teeth ever get as large as the distance between the two sides of the expander because the teeth start moving back together even before expansion is complete. In fact, it is not uncommon for the gap between the two front teeth to be completely closed by the time the expander is removed.

Knowing ahead of time that an expander could create a gap between the front teeth and that it will go away on its own is reassuring. If what you see in your mouth or in the mouth of your child does not seem to follow the pattern described above, give any one of our Sondhi-Biggs Orthodontics team members a call and let us know.