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As an orthodontist, I often get asked about how long a palatal expander will stay in. The truth is, it varies from patient to patient, and there are many factors that can influence the length of treatment. However, there’s a common range that most patients fit into.
You can expect to wear your palate expander for about 6 months, although treatment times can vary from 4 to 9 months. 6 months is the most common treatment length, long enough to allow the suture to fill up with bone and short enough not to cause other issues inside the mouth.
Palate expanders are commonly used on pre-teenage children because that’s the sweet-spot for getting the best results. So, if you’re reading this, you’re probably a parent researching everything there is to know about palate expanders.
This article will hopefully answer all your questions, and then some! If you’re still in doubt, feel free to explore our many resources on palate expanders.
How long will you wear your palate expander?
Palatal expanders are also called RPEs, which stands for Rapid Palatal Expansion, and that’s because the expansion itself really is quick. Don’t worry, I’ll explain why expanders need to stay in for so long, but before I do, you need to know what happens during that crucial first month.
What happens during the first month
Right after your child’s expander gets cemented, your orthodontist will most likely turn the expander’s key and teach you the basics of doing this at home.
Most orthodontists like to turn the key at a rate of 1 to 2 turns per day. This equals to an expansion of .25 to .50 mm per day, which is not a whole lot, but it still might feel a bit intense.
Depending on how much expansion your child needs, and whether you turn the screw once or twice per day, the expansion phase can last anything from 3 to 6 weeks.
The maximum amount of turns a typical screw can withstand is 40 turns. In some cases, 40 turns are a bit excessive, but they’re still safe in case a parent forgets the rules and keeps turning the screw until the next appointment (it’s happened to some of my patients, but thankfully everything was fine).
I tell my patients’ parents to stop turning the screw when the molars have achieved optimum expansion levels. So, for some patients that can mean 28 turns, for others it can mean 38 turns and everything in between. This is one of the reasons why treatment time varies a little bit.
Aside from turning the screw every day, here’s what else to expect during month one:
Expect a huge gap. During the first couple of weeks of turning the screw, expect a significant gap to open up between the front teeth. We’ll talk more about this gap in another article, but what you need to know for now is that the gap is an excellent sign that things are working as they should and the suture is opening.
Expect some pain and tension. Your child will probably complain a little bit after you turn the screw, which is why I recommend you do it in the evening, so he or she sleeps on it and has time to adjust. Some tooth pain while eating is also normal, especially in the molars and incisors.
Expect a cute lisp. During the first month, your child will go through an adjustment phase with their palate expander. This involves chewing, brushing and yes, speaking. I love to have fun with my patients and make them say “Mississippi” with the expander in. But, jokes aside, when my patients come back after 4-6 weeks, their speech is fine.
IMPORTANT: During the first month it’s absolutely crucial that your child’s palate expander doesn’t break or come off. The most sneaky issue is when the expander band becomes loose on one molar but not the other. This prevents the expander from doing its job, which is why your child needs to eat soft foods to prevent accidents and you need to check the bands daily.
Why we don’t want to remove palate expanders early
Palate expanders are fixed devices and they need to stay inside the mouth for 6 to 9 months for several reasons. Perhaps the most important reason is preventing relapse.
When we open up and expand the suture, we end up with an empty space between two bone plates that will gradually fill up with bone. The bone with reorganize and create a new suture.
Contrary to popular belief, we don’t “break” the maxilla when we expand it, because it’s already made up of two bones. What the expander does by applying pressure is simply to separate those bones further apart. Then mother nature takes its course and makes more bone for us.
This bone-making process takes a while, so this is why most patients need to keep their expanders in place for at least 3 months after the expansion has stopped. As a result, expanders need to stay in for a minimum of 4 months, but 6 months is better if we don’t want relapse to occur.
Here’s an example to help you understand what happens if an expander *accidentally* comes off during the first month. In a matter of minutes, or even seconds, the maxilla bone plates will come together, because the suture is empty and there’s no new bone preventing it to close back.
The maxillary suture is subject to a lot of pressure from the other bones that are fused to it – bones that make up our nose and cheeks – and it makes sense that they want to snap back.
Unfortunately, many children don’t pay attention to their eating habits and end up dislodging their palate expander, making the expansion process useless.
We’ve covered the relapse that we don’t want – the relapse of the suture. But there’s a type of relapse that we do want, and it’s a good reason to get the expander off early: the relapse of over-expanded molars.
The most popular expanders we use are banded expanders. These have two bands that sit on the first molars. Molars are strong teeth and they act as pillars for the expander to sit on while opening the suture. But even these pillars can become weakened, so there’s a natural limit to our expansion.
Molars can become over-expanded, and this is something we, as orthodontists, need to pay close attention to. In most cases, we intentionally over-expand the molars up to a certain point, because we know that as soon as they’re free from the device, they’ll bounce back a few mm inside the maxilla.
Factors that affect Expander treatment length
Now that you know that expanders are usually kept in between 4 to 9 months, it’s time to learn about what factors affect treatment time. Here are some things to consider when it comes to the length of orthodontic treatment with expanders:
The patient’s age
Age is a pretty big factor that affects how long you’ll be wearing an expander. In general, younger kids might need to wear one for a longer time than teenagers. Pre-teens usually wear expanders for about 6 to 9 months, while teens might need to wear them for about 4 to 6 months.
This is because younger kids’ bones are still growing and are more flexible, which makes it easier for the expander to do its job, but also easier for relapse to occur. This is not a set rule, though.
Type of malocclusion
The severity and type of malocclusion can also affect how long you’ll need to wear an expander. Patients with more severe cases, like crossbites or class III malocclusions, might have to wear their expander for a longer time. For example, if you have a bilateral crossbite, where your top teeth sit inside your bottom teeth, you might need to wear your expander for up to a year, in tandem with braces.
But if you have mild crowding or good transverse dimensions, and your molars are already in a good position, you might have a shorter treatment time. That’s because the expander can create an imbalance in your bite if worn for too long, which is why we count on molar relapse. In some cases, it might be helpful for your molars to move back a little bit, which can reduce the need for a major expansion of the bottom teeth.
The type of treatment plan your orthodontist recommends can also impact how long you’ll need to wear your expander. If you need to use a facemask to fix a class III malocclusion, for example, you’ll likely have to wear your expander for a longer time. Usually, that means about 9 to 12 months. With facemask treatment, you wear rubber bands and attach the mask to the hooks on your expander, which can add some extra time to your treatment.
Will your child need a retainer after Expansion?
Many orthodontists recommend the use of retainers after expanding the palate and gaining a lot of space, and I can see how that’s useful. The best time to use palate expanders is between 8 to 11 years, so before braces, during a treatment stage that’s called “Phase 1”.
After Phase 1, the expander comes off, and we wait for the permanent teeth to fully come in before moving on to braces. During this time, we can choose to create some form of retention, like a removable plate or Hawley retainer, or we can just allow the teeth to naturally settle and count on the suture expansion that we already created.
I personally like the second option, and while I’ll most likely lose some space and transverse dimension, it’s nothing a little time in braces can’t fix. Other orthodontists prefer to keep a retainer in, and studies have shown that 6 months is the optimum time to achieve retention after using a palate expander.
Keep in mind, though, that your child is still growing, and, in my opinion, the less we intervene, the better.
If you’re a teenager or an adult wearing a palate expander, you’re most likely going to need braces soon, or you’re already wearing your expander in tandem with braces. In this scenario, you will not need any extra retention aside from the Hawley or Essix retainer you’ll receive once the treatment is over.
Hopefully, you’re more confident about your child’s expander at this point, and you’ll do everything to make sure that the device doesn’t accidentally break or come off.
While 6 to 9 months might seem like a lot of time, it goes by in the blink of an eye in the grand scheme of orthodontic treatments. And since the palate expander is fixed, you can’t do much about it anyway, so it’s best to just sit back, be patient, and let it do its thing.