My Kid Needs An Expander. What Is That?

My Kid Needs An Expander. What Is That?
Posted on 03/05/2015


An expander is a very common early orthodontic appliance. It is most often utilized to predictably widen an upper jaw that is deficient in its growth and therefore deficient in the space needed to accommodate the larger adult tooth sizes. Patients who require this appliance are most often detected at an early age through the identification of a crossbite or severe crowding of the upper teeth.

What is a crossbite?
When biting, all of the top teeth should overlap the bottom teeth on the outside. When top teeth on either one side or both sides do not overlap on the outside and instead fit inside of the bottom teeth it is termed a crossbite. This can be found in the back or in the front and with just one tooth or several teeth. When it is found in the back and multiple teeth are involved it means that the upper jaw is not growing large enough. “The lid is too small to fit on the jar”…is a common analogy to help understand why developing the proper size of the upper jaw is so important to how the top and bottom permanent teeth will eventually fit together.

How does an expander work?
In early fetal development the upper jaw is actually formed by more than one bone. The areas where these bones come together to form a single bone remain as growth sutures. These growth sutures are active for most children up until their early adolescent years. An expander predictably widens the upper jaw by taking advantage of these active growth sutures. The appliance itself is constructed to attach to multiple upper permanent teeth, which are used as anchors to translate a constant force to these skeletal growth sutures.

What does it mean to turn the expander?
The appliance is “turned” or “activated” on a daily basis at home by a parent. The appliance slowly expands with each turn. Each turn expands the appliance only ¼ mm. The amount of total turns needed is determined by the doctor and is monitored closely throughout the duration of the expander treatment. The doctor will give an in-office demonstration of how to complete a turn, making sure parents are comfortable with the technique before leaving the office.

Is there any pain or discomfort during this treatment?
Generally, most patients do not experience significant pain or discomfort. If anything patients will notice a small amount of pressure in the hours following each turn. I always advise parents to complete turns at night before bed. That way kids fall asleep before they ever notice any change in pressure. Rarely do I hear reports from parents that their child required any pain medication to cope. If significant sharp shooting pain develops around the teeth or in the mid-face area the doctor should be contacted as this is not normal.

What diet restrictions exist with an expander?
It will take a few days for a child to adapt to the expander appliance. First, the mouth will produce more saliva until the body realizes the expander is not food. Don’t be surprised if your child is slurping and swallowing a lot during that first day. Secondly, the tongue needs to adapt to the new environment. Eating and swallowing will initially require a more conscious effort. We advise to start with a softer diet for the first few days until swallowing becomes more natural. After that they can eat any foods they are comfortable with. Kids need to avoid sticky foods that can loosen the appliance from the teeth. They also need to avoid applying repetitive forces to the appliance via the tongue. Over time these forces can loosen the appliance. If the appliance becomes loose it needs to be re-cemented as quickly as possible in order to avoid losing any progress already gained.

Speaking will also be altered during the first few days. We advise for kids to go home that first day and practice talking or reading out loud. This will accelerate the adjustment period. Kids are incredibly adaptive and usually take no more than a few days to become completely adjusted to this appliance.

A large gap between the two front teeth will develop. Don’t Panic!
The path of the growth suture runs right between the two front teeth. With each turn of the expander the distance between those two teeth should get slightly larger. If a child begins with a space between their two front teeth then that space will get bigger and bigger. If a child begins with no space between their two front teeth, a space will definitely develop and grow in size throughout. This is not only normal and expected but doctors will look for this space to verify that true skeletal growth is occurring. An absence of this space is more concerning then the presence of the space. The beginning relationship of the two front teeth will return shortly after the turns are stopped.

The expander is a wonderfully effective appliance in aiding the skeletal development for many children and adolescents. This appliance is most effective and the results are most stable when used in the early years before closure of the growth sutures. The age limits for this are around 12-13 years for girls and 13-14 years for boys. Treatment initiated beyond these ages usually results in more dental rather than skeletal effects, which are more prone to long term relapse. General dentist are very aware of these age limits and make timely referrals for such reasons. However, as mentioned in my previous blog post, it is always advantageous to receive an early orthodontic consult even if no prior recommendation has been given. Early problems, such as crossbites, are rare but if they are not detected and treated early, it can cause significant challenges and often compromised results at an older age.

Dr. Justin Wild DDS, MS