
Dental Expanders: A Closer Look
What is a Dental Expander?
A dental expander is a specialized orthodontic appliance used to widen the maxilla (or upper jaw). This process, known as palatal expansion, can be beneficial for individuals with crowded teeth, a narrow or v-shaped upper arch, mouth breathing, airway issues, snoring, or various types of malocclusions (misalignments of the teeth and jaws).
How Does a Dental Expander Work?
Dental expanders typically have a metal frame and bands that fit over the upper teeth. This frame is connected to a screw or key that, when turned, applies gentle pressure to the palate (the roof of the mouth). Over time, this pressure gradually widens the upper jaw, creating more space for the teeth to align properly.
The maxilla is comprised of two bones which come together in the center at the maxillary suture. The younger patients are the easier it is to achieve expansion as the suture is still pliable and able to be widened. As patients get older the suture becomes more and more interdigitated with bone. Once a child has passed their pubertal growth the suture becomes completely fused and at this point skeletal expansion is only possible with a MARPE device or orthognathic surgery. Traditional expanders that are used after the maxillary suture has fused result in tipping of the back teeth (dental tipping) which may be able to camouflage a narrow maxilla and correct posterior crossbites, however a limit to how much dental tipping is safe to do should be kept in mind. Tipping the back teeth too far may result in the need for future bone/gum grafts.
This is why it is best for children to see an orthodontist prior to age of 7 to assess whether or not an expander is needed. During childhood, expansion is an easy, non-invasive, predictable procedure, however in adulthood the methods become more involved, more timely, and more difficult to achieve. ย
Why Would Someone Need a Dental Expander?
There are several reasons why an orthodontist might recommend a dental expander:
- Crowded Teeth: If your teeth are too close together, a dental expander can create additional space, allowing them space to align.
- Narrow Maxilla: A narrow upper jaw can contribute to crowded teeth, a crossbite, mouth breathing, snoring, etc. A dental expander can help to widen the jaw, improve nasal breathing and create the space necessary for teeth to align or permanent teeth to erupt.
- Certain Types of Malocclusion: Dental expanders can be used to treat specific types of malocclusions, such as crossbites or patients with reverse overjet (or underbites).
Types of Dental Expanders
There are several types of dental expanders, each with its own unique characteristics:
- Fixed Expanders: Commonly called rapid palatal expanders or (RPEs) are made of metal, are cemented to the teeth and cannot be removed by the patient. They are turned by the patient or parent as instructed.
- Removable Traditional Expanders: These expanders can be taken out of the mouth for cleaning or comfort. The expander screw is generally made in acrylic and patients need to turn the expander just like a fixed expander.
- Invisalign Palatal Expanders: The newest expander on the market! It’s removable, more comfortable and involves no turning by the patient.
- MARPE: Once the suture in the upper jaw is fused together, the only way to separate it and achieve skeletal expansion is by using a MARPE or Mini-Screw Assisted Rapid Palatal Expander. This expander involves 4 screws which engage into the nasal bones in order to widen the upper jaw.















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