The Importance of Palatal Expanders
- Decreased airway volume
How Do They Work?
The upper palate of a child is not solid until around age 12-14 for girls and 14-16
for boys. Until this fusion, the roof of the mouth is divided in half by a suture line.
Using a screw mechanism, activated by twice-a-day key turns, an expander
gently pushes apart these halves and new bone forms, permanently widening the
Why Get an Expander?
“The relationship between the upper and lower
jaw is important to having a “good bite…”
One of the reasons that the AAO recommends children having an orthodontic
consult at age 7, is that this is about the age an underdeveloped (small) maxilla
can be identified. Because this is not something that will naturally correct itself
given time, it’s an important opportunity for the orthodontist. He can plan ahead
with intention to widen the arch of the upper jaw using an expander. This early
intervention can allow for teeth to come in with ease.
Without this treatment, these teeth will either come in crooked, over another
tooth, or become impacted and not erupt at all.
Taking advantage of this window of opportunity helps prevent the need for
extractions, extensive future orthodontic work or possibly even surgical
The main goal of the expander is to bring balance between the jaws.
Underbites, crossbites, and crowding can all be signs of an underdeveloped
One issue that can arise from unbalanced jaw width is problems caused by
deviation of the lower jaw to fit upper teeth. The relationship between the upper
and lower jaw is important to having a “good bite” or occlusion. The constant shift
of the lower jaw to chew food and smile can lead to enamel wear, asymmetric
growth and TMJ strain.
Another benefit of expansion is improving airway passages. Sleep apnea, mouth
breathing, snoring, and dry mouth can all be helped by widening the upper jaw.
Optimizing anterior airway passages maximizes air flow; which, although not
curing things like obstructive apnea, can lessen the complications of breathing
problems for many children.
When to get an Expander?
“Expanders provide a deeper function by
expanding the bones, while braces align the
teeth on the surface.”
Expanders are best used during phase 1 treatment when an underdeveloped jaw
is noticed but after other facial sutures are fused at around age 7 or 8.
The appliance can also be used in conjunction with comprehensive braces
depending on the age and progression of dental development. Expanders
provide a deeper function by expanding the bones, while braces align the teeth
on the surface.
After puberty, expansion can be attempted, but sometimes, surgery is required
for actual palatal expansion. Sometimes, expanders on adults can seem to be
working, but in actuality the teeth are just getting tipped outward, which can mask
deeper structural problems and in the long-term cause issues with dental health.
Types of Expanders?
The most commonly used expander, and the one we’re discussing today, is the
Fixed Rapid Palatal Expanders. They work as described above. They are rigid
metal, sometimes with acrylic, and depending on the model, have different
layouts of arms and bands for support.
Removable expanders are a different, retainer-like, device made for slight
surface-level arch expansion. It works more so by tipping out the teeth rather
than actually expanding the palate.
For adults or difficult cases there are implant or surgical assisted expanders
which use implanted metal anchors and/or surgical intervention to break a fused
suture in concert with a fixed expander. This is an involved, heavy-duty option.
Teeth can only be moved so much. This kind of expander is used to achieve
ideal results when the underlying problem is jaw discrepancy of an adult who has
a fused palate.
Regardless of the type, all expanders work with a screw mechanism, activated by
a key, that provides for progressive increase of width.
What’s it Like?
The process begins by taking an impression or a 3D scan. This way, the expander is custom fitted and seamless for each patient.
Once created, the device is placed in the roof of the mouth and glued to the molars. It’s a quick procedure with no pain. Because there’s now a foreign object in the way, speaking and swallowing will take some practice.
Your orthodontist will provide you with a special key and demonstrate how and when to do your “turns.”
That goes like this:
Your orthodontist will provide you with a special key and demonstrate how and
when to do your “turns.”
That goes like this:
● Ensure good lighting and have the patient sit down and tilt their head back
to maximize visibility.
● Insert the supplied expander key into the hole at the center of the device at
the roof of the mouth.
● Once the key is fully engaged in the hole, push the key towards the back of
the throat until another hole is visible.
● This is a complete turn.
Based on your orthodontist’s directions, the turns will take place no more than twice a day,
morning and night, for a total of anywhere between 10-50 turns depending on how much
expansion is needed. After 5-6 turns, you will begin to notice a space, or diastema, widening
between the two front teeth. This will be corrected later. There is a slower method of expansion
which reduces the likelihood of this space, but it provides less desired bony expansion overall.
Your orthodontist will want to check on progress after about 2 weeks and every couple
weeks until the desired amount of expansion is achieved. It will only take a couple visits
before the turning part of the expansion will be complete. The expander stays in place for about
6 months to ensure the bone tissue has plenty of time to fill in the gap. During this time you will
only have appointments every couple months or so to check on placement, progress and
Finally, you will go in to have the expander removed. Using a special tool, the bands on the
device will be popped off the tooth and the excess glue will be removed using a bur.
If you are already in braces, you will continue with treatment as usual. If it’s time for phase
2, you will get your braces placed. If you aren’t quite ready for braces, the orthodontist will
keep you in observation until phase 2 treatment begins.
Concerns and Troubleshooting
“The first question most people have about
expanders is: “Will it hurt?””
The first question most people have about expanders is: “Will it hurt?”
The general experience of the actual expansion turn is a sensation of pressure. During the
first few days of acclimation soreness to the palate, surrounding facial structures and molars
may occur. Tingling in the nose and roof of the mouth, teeth sensitivity, and spots of
irritation to the inside of the mouth are common sensations. OTC pain medication, warm
salt water swishing, and dental wax can help during this period as can avoiding turns before
eating or right before bed. If any severe pain is felt, stop turns immediately and call your
Just like braces, the mouth, lips and tongue take time to get used to metal irritants. Calluses
will develop at places of rubbing after a couple days. Dental wax can be used to increase
comfort until then.
The turns should be completed no more than twice a day, morning and night.
The total number of turns is more important than the frequency. Do not try to catch up on
missed turns by doing them more often than twice a day.
One rather irksome side effect of this new foreign object in your mouth is drooling. New
stimulus in the mouth causes increased saliva production (in case it’s food.) To compound
the issue, swallowing can take some getting used to as something is now in the way of the
Another thing that will take some re-learning is speech. Again, the tongue must acclimate to
this new bulk in the way taking up room in the mouth.
With practice, you’ll be back to normal in no time.
Fixed appliances, like expanders, are repeat offenders when it comes to bond failure. If the
fit and bonding isn’t perfect, it’s at risk for popping off. This can be an issue during the first
week or so of getting an expander placed, hopefully before much expansion progress was
made. The suture line pulls back together very quickly if the expander falls out, so call your
orthodontist as soon as possible.
Apart from an Xray, you will not be able to see the space widening in your palate. However, as
mentioned, you can expect to notice the space between upper front teeth growing. Once the
expander is removed, this space will naturally lessen and it will be fully corrected in phase 2 or
with continued treatment.
Having a water flosser on hand when you have an expander will make life much easier. Food
can easily get trapped underneath the center of the appliance. Trapped food can cause bad
breath and decay. As usual, we recommend brushing morning, night and after meals, but a
water flosser is a life saver after a meal to easily blast the food out of the crannies.