Dr. Greg Jorgensen
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Rio Rancho, NM 87124

The Jorgensen Orthodontics Blog

My Orthodontic Expander Made a Huge Gap Between My Teeth

Posted by Dr. Jorgensen on January 25th, 2013

Over the past couple of decades there has been a shift in orthodontics from extracting teeth to expanding the arches when there is crowding present. Expanders work great, but there are some side effects that catch parents by surprise. One of them is the appearance and disappearance of a gap between the front teeth.

The palate or roof of the mouth is made up of two bones joined together down the center by a junction called a suture. When a patient is young, this suture is made up of stretchable cartilage that is the area where growth takes place (a “growth plate”). After skeletal maturation somewhere between 14 and 17 years of age, this suture fuses and the palate becomes a single solid structure. Expanders take advantage of the presence of the growth plate if they are used before it is 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 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 desirable.

After the expander has provided the desired amount of expansion, the orthodontist will typically leave it in place for several months holding the two halves of the palate apart while new bone develops between them. Upon removal of the expander, there is always some relapse or loss of arch width. Most orthodontists over-correct by a few millimeters in anticipation of this change.

During this stabilization period, the gap created during expansion tends to close on its own. This happens slowly over time, but it shocks many parents the first time they notice it is smaller or gone altogether. Understandably, many parents call our office worried that the expander has slipped and that the benefits achieved during the activation phase have been lost.

During palatal expansion there are two forces on the teeth. The force created by the expander pushes the palate apart and a gap appears between the teeth. At the same time there is an opposite force acting on the teeth produced by the gum tissues. Just like other soft tissues in the body, the gums are elastic. As the expander pushes outward, the gum tissue starts pulling the teeth back together. You can tell this is happening 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. Another sign that the front teeth are being pulled back together is that they get sore and feel a little loose during expansion for no obvious reason (just like when braces are moving them). Now you know that they are being pulled back together by the elastic fibers in your gum tissue. 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 will create a gap between the front teeth and that it will go away on its own is reassuring when it happens. Understanding what is normal will save you some worry and an unnecessary phone call to your orthodontist. If what you see in your mouth or in the mouth of your child does not seem to follow the pattern described however, give your orthodontic office a call and let them know. It is better to be safe than sorry!

NOTE: The author, Dr. Greg Jorgensen, is a board-certified orthodontist who is in the private practice of orthodontics in Rio Rancho, New Mexico (a suburb on the westside of Albuquerque). He was trained at BYU, Washington University in St. Louis, and the University of Iowa in the United States. Dr. Jorgensen’s 25 years of specialty practice and 10,000 finished cases qualify him an expert in two-phase treatment, extraction and non-extraction therapy, functional orthodontics, clear aligners (Invisalign), and multiple bracket systems (including conventional braces, Damon and other self-ligating brackets, Suresmile, and lingual braces). This blog for informational purposes only and is designed to help consumers understand currently accepted orthodontic concepts. It is not a venue for debating alternative treatment theories. Dr. Jorgensen is licensed to diagnose and treat patients only in the state of New Mexico. He cannot diagnose cases described in comments nor can he select treatment plans for readers. Because he has over 25,000 readers each month, it is impossible for him respond to all questions. Please read all of the comments associated with each article as most of the questions he receives each week have been asked and answered previously. The opinions expressed here are protected by copyright laws and can only be used with written permission from the author.

228 comments so far in response to “My Orthodontic Expander Made a Huge Gap Between My Teeth”

  1. Michaela says:

    Hello, I am a 18-year-old who got a rapid palatal expander five days ago. I do see a gap starting to form, but it’s a little one and my front teeth have been hurting like crazy since yesterday (got worse today.)I haven’t taken the expander off either, isn’t it too early for the front teeth to start getting back together?
    Also, I have a crossbite that needs corrected and I’ll be putting in braces for both my upper and lower teeth. Will some of my crossbite be straightened out with the expander?

  2. JoJo says:

    I got an expander that you can take out and put back in. My orthodontist said I have to wear it for 6-8 months or more, how long will it take before I start seeing change and if I wear it everyday and sleep with it after each tightening at night everyday will the change be faster?

    • Expanders must be worn full-time if you hope to see change anyway. I am not a fan of removable expanders. If it is working for you, you will probably see some spacing between the upper front teeth within two weeks.

  3. Hemal Patel says:

    Hello Doc,
    My 11-year old daughter has a thumb sucking habit. I recently visited an orthodontist in this regard. She is advised to undergo a treatment in two phases as she still has to lose 8 molar teeth (6 upper 2 lower). Her first phase will be of using an expander on the top plus braces. And then the second phase will be to correct the cross-bite. Is it OK for my 11-year old to undergo such a long treatment? Would this impair her speech? Will the soreness go away by itself?

  4. Brooke says:

    I’m 15, and I just got an expander a few days ago. I really do not want a space in my front teeth, so the orthodontist said that by turning the key every other day we would prevent the space from forming. He promised that no space would be created, but is it even possible? The last orthodontist that I went to said that a space was inevitable when it comes to expanding.

    • It is feasible that you may get less of a space if you turn your expander less, but there is no way to predict that for sure. He’s hoping that slowing the expansion will give your teeth more time to drift together while you’re in the middle of expansion. That may or may not happen. One thing is for sure, if you turn your key half as much, your expander will be in twice as long.

  5. Michelle Boraz says:

    My 6 year old got a RPE yesterday and it fell out completely. There are no metal parts that wrap around back molars…just plastic part that glues to her back teeth and apparently the glue didn’t set strongly enough. Is this something to worry about, skillwise as far as the orthodontist she’s being cared for by? I took her in to take a look when I told them it’d fallen out, but that she’d pushed it back in, and in the lobby of the facility she was examined and told it was fine since it “clicked” back in place when she pushed it back to the roof of her mouth. Just don’t touch it again and it should be okay. Come back at the scheduled appointment in two weeks.

    I asked my daughter to not push it back into place the next time she felt it fall out, just come to me so I can see exactly how it fell out if it happened again. When she came to me, it was completely out, sitting on her tongue. This same orthodontist mentioned another patient had too much glue and, it had taken 25 minutes and lots of cutting piece by piece to get the thing out … and so she was reticent to use too much glue.

    Worried about taking my daughter back there. It seems like there should be a more advanced way of getting these things to stay.

    • Something doesn’t sound right here. The expander is either permanent or removable. If it was designed to be taken out and snapped back in, you should have been told that. I would go back and speak directly to the orthodontist about your concerns.

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