Dr. Greg Jorgensen
(505) 891-9440
1401 Barbara Loop SE
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.

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

  1. linda mcdermott says:

    My daughter had a fixed RPE placed a week ago with bands around her 6 yr molars. She is 13 yrs, 4 mos old & we have been turning it once a day for 7 days. So far, we haven’t noticed any increase in the gap between her front teeth, but the molars have tipped noticeably outwards, especially on the left side. Is this normal for the first week?

  2. Jose says:

    I’ve had my top and bottom expanders on for about a week. My dentist told me to turn it ever other day. The first few turns I woul feel some pressure, but not discomfort. I am not at my 7th turn, and I’m getting very little pressure on my lower expander. Is this normal? What could cause it?

  3. cassidy says:

    hello, i got a palate expander today and he said i would comeback in a month to see if it was good or if i need it longer at that point. i was wondering if you would be able to give me an estimate of how long it will take before instant seeing a change. Thank you

  4. Jennifer Wolsky says:

    My daughter has palatal issues due to mouth breathing- a v shaped palate and front teeth that stick out. She got a palatal expander in July. We turned it twice a day for two weeks. The expander was removed 6 weeks after the final turn. I’m concerned about the bone not being completely filled in. They waited 2 weeks before they put hardware on her teeth to hold everything in place. Should I be concerned or is 6 weeks enough time for the bone to fill in? As a side note, my daughter says that the expander has helped her breathing.

    • There are different opinions on the amount of time needed for bone healing after expansion. I usually wait a couple of months, but I know others who keep the expander in for a year. Hopefully your daughter’s braces will stabilize the tooth position that you’ve achieved with the expander.

  5. Christy says:

    My sons dentist put an expander in a year ago which left a gap in his front teeth the orthodontist says it’s time to take the braces off but he still has a gap at the bottom of those front teeth. Is this common? The ortho says it just his teeth which I don’t believe because it wasn’t like tha before the expander was put on. Is there anything that can be done to fix it?

  6. Alexis says:

    If I push the key forward will it close my gap

    • Reversing the expander will close the gap, but it will also undo all of the progress you’ve made. Please be patient and the gap will close naturally on its own (or shortly after your braces go on)

  7. Shameha says:

    Hi, I recently got my palate expander and I’m done turning it. Now my orthodontist said I have to wait 6 weeks before getting braces. Why?

    • Because you need to let the growth plate or suture solidify before moving the teeth into that area. The first bone to fill in to the newly expanded area is still soft and immature for many weeks. I usually wait 8 to 12 weeks to be safe

      • Shameha says:

        Alright, thank you.
        How long does it usually take for the gap to be completely close? I’ve had the gap over 2 weeks and i haven’t noticed any change.

  8. Maria says:

    My son’s ortho wants to use the palate expander and braces at the same time. I would like to know your opinion. He claims that if done that way, he will not get the gap between his front teeth.

    • Some doctors feel comfortable doing this. I think it might be safe if you go really slow. The problem is that if you proceed at the normal pace (2 turns per day), you’ll spread the palate and there will not only be a space between the front teeth, there will be a gap between the two halves of the palatal bone under the tissue. If you have braces on the teeth and scoot the front teeth right into this space or immature bone, you could risk not having enough support to keep the front teeth! I’ve never done it like your orthodontist is proposing for that reason. It usually takes about two months for the bone to form and mature after the end of expansion, so I don’t move the teeth into that area for two months for that reason. I suppose if you slowed the rate of expansion, you might be able to reduce the risk, but I have no evidence to support that theory.

  9. Lily says:

    After reading this I noticed it said the gap usually closes while the expander is still in your mouth. How long does that take after the key turning of the expander is finished? I was also wondering if there was any way to prevent the gap in my front teeth from growing. I’ve had the expanded in for about 2.5- weeks and it didn’t start getting a gap until a week ago and now the gap is very big. It’s only a cosmetic flaw and I still have 5 more key turns but is there anything I can do to stop it from growing anymore?

    • The spontaneous closure of the space happens at the same time that the activations are being made. The space that develops is a sign that it is working! You should not try to close the space pre-maturely as the new underlying bone is not ready to support the teeth. The space is temporary and will be gone very soon. Just be patient. Good luck!

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