Everything You Need to Know About Palatal Expanders in Orthodontics

Palatal expanders are commonly used orthodontic appliances which can correct the upper jaw size and address facial asymmetry. You will see palatal expanders commonly used in children, adolescents, and teenagers as their jaws are still growing and respond well to any corrective orthodontic treatment. It can be used in adults as well but only under certain conditions. This article will help educate you on why, how, and when palatal expanders are needed and on the types of palate expanders available.

Understanding Basics – The Anatomy of the Jaws

Your jaw contains two bones: the upper jaw bone (maxilla) and the lower jaw bone (mandible). Your maxilla, in turn, contains two bones that meet in the center to form the palate or the roof of your mouth (1) (Figure 1). For functional reasons (such as eating and proper articulation of words), the upper jaw must be larger than the lower jaw. When we close our mouth the inner surfaces of the upper teeth fit snuggly with the outer edges of the end teeth – like a lid on a jar. The lid is always wider than the rim of the jar. This is the ideal fit of the teeth which creates a healthy stable bite. 

Figure 1: Basic Facial Anatomy

diagram of basic facial anatomy

Some people have a smaller maxilla compared to their mandible which can cause some significant problems.

If the upper jaw is narrower compared to the lower jaw, then the teeth of the upper and lower jaws will interfere with the proper closure of the mouth. When the lower jaw does not have the proper space to comfortably fit into the upper jaw, it will deviate to the side (either left or right) to attain a more comfortable bite. This will cause a facial asymmetry which is typically temporary if it is addressed quickly. But if the deviated bite persists for a long time (years) it will lead to permanent asymmetry. If uncorrected, a narrow and deviated jaw can cause breathing issues, snoring, and even sleep apnea.

It may sound scary but the solution is quite straightforward. This is when palatal expanders can help you.

A palatal expander can help expand or widen the upper jaw which creates more space so that the lower jaw fits in comfortably. In turn, the lower jaw will return to a more central position and give your face a more symmetric appearance. Widening the upper jaw also results in a widening of the roof of the mouth. The roof of the mouth is also the base of the nose. Thus, palatal expansion will also help to open up your nasopharyngeal passage and may help minimize snoring and sleep apnea.

Palatal Expanders – What are They and How do They Work?

A palate expander — also known as an orthodontic expander — is an oral orthopedic device. It is used to widen a narrow maxilla (upper jaw). Remember how your maxilla contains two bones that meet in the center? This device sits in the center of the roof of your mouth and slowly moves both halves of your maxilla apart in order to widen and expand your upper jaw (2).

Orthodontic expanders are most effective in children. But this device can also be used for teens and adults.

When we talk about palatal expansion, it is important to realized there are two components: skeletal expansion and dental expansion.

First, let’s have a look at skeletal expansion.

When we talk about skeletal expansion, we are talking about expansion of the bones. The palate is the bone that makes the roof of your mouth. The palate has two halves that are joined by a “suture” in the middle (Figure 2). When a palate expander is used, it applies gentle, steady pressure on each side of your palate. This steady pressure pushes the two halves apart, expanding your upper jaw over time. As your palate slowly expands, new bone regenerates and fills the space along the center suture line.

Figure 2: Basic Functioning of Palatal Expanders – Figures (a) to (c) shows the basic anatomy of the palate (roof of the mouth) Mx = maxilla, mps = Mid palatal sutures (where maxillary bones meet). Figures (d) and (e) show palatal expanders in use.

How palatal expanders work


Now let’s discuss dental expansion.

Dental expansion refers to when teeth are moved within the bone to a wider position. This does not mean that the bone itself is expanding. Dental expansion can happen with or without skeletal expansion and usually there is a combination of both types of expansion that take place during orthodontic treatment.

At What Age is a Dental Expander Helpful?

Palatal expansion is more rapid and successful before the fusion of the palatal suture. This is why it is often done in early orthodontic treatment (also known as early interceptive treatment or phase 1 orthodontics) and is often use to create space before the adult teeth erupt into the mouth. The palatal suture will fuse together at around 14-15 years of age (3). If palatal expansion is attempted between the ages of 7 and 14, the expansion usually contains a mix of skeletal and dental expansion. The younger the age, the more the expansion will be skeletal. If palatal expansion is done with increasing age, the midpalatal sutures fuse and there is often not enough room for palatal expansion. In such cases, most of the movement occurs due to dental expansion.

Who Needs a Palatal Expander?

Your dentist or orthodontist may recommend a palatal expander for the following reasons (4):

  • Narrow maxilla
  • Overcrowding of teeth (crowded teeth)
  • Overlapping teeth
  • Crooked teeth
  • Impacted teeth
  • Misaligned bite
  • Difficulty in chewing

What are the Different Types of Palatal Expanders?

There are various types of palatal expanders available in the market (4). The type of palatal expander your orthodontist recommends would depend on your age, the severity of the condition, compliance, dental development, etc.

  • Removable Palatal Expanders: A removable palatal expander looks similar to an orthodontic retainer but has an expansion screw in the center to allow the widening of the upper jaw. Removable expanders are recommended for people who need just a little bit of palatal expansion and have good compliance. These are the least common type of expanders.
  • Rapid Palatal Expanders (Fixed Expanders): A rapid palatal expander is a fixed expander. It is placed on your palate and cemented to your upper posterior teeth. There is a tiny screw in the middle of the expander and you turn it a little every day with a specific expander key. You can start to see significant results in a few weeks of turning the screw. You will be given instructions on how to turn the screw.Based on the type of material and fixation method use, the following are some common types:
  • Hyrax Expander (Figure 3): It contains metal bands fixed onto the back teeth and a screw in the middle. This is the most comfortable and common type of expander used by orthodontists.
Photo of a Hyrax expander

  • HAAS Expander (Figure 4): It contains metal bands fixed onto the back teeth, a screw in the middle and acrylic pads on both sides of the screw. The acrylic pads serve to apply lateral forces to both the teeth and the walls of the palate, but can be quite uncomfortable and irritating to the palate.
Image of a HAAS palate expander
  • QUAD Helix Expander (Figure 5): It is completely metal and contains 4 helical loops and is fixed on the back molars. It can be used to apply force in different directions if asymmetric expansion is needed. This type of expander is rarely used anymore.
Image of a Quad Helix Expander
  • Surgically Assisted Rapid Palatal Expander (SARPE): This type of expansion technique is used in moderate to severe cases and in adults who have fully fused palatal sutures. In this technique, an orthodontist first places a rapid palatal expander (RPE). Then an oral surgeon surgically cuts down the center line of the maxilla to separate the two halves to allow expansion of the palatal suture. Just like a rapid palatal expander, SARPE is also anchored to the upper posterior. The expander is turned until the desired width of the maxilla is achieved.
  • Temporary Anchorage Device (TAD) Supported Expander (Figure 6): This type of expansion technique is used in late teenagers or adults where the palatal suture is fully fused. It attaches to the jaw using temporary anchorage devices (TADs) which are also known as mini-implants or mini-screws. The screws are placed to the left and right of the palatal suture and pressure is applied until the suture breaks open. It can be very painful, but is a non-surgical alternative to achieve expansion in adults.

How Painful is a Palatal Expander?

 Just like every other orthodontic device, the palatal expander will cause minor discomfort in the initial first few days. Some people also feel discomfort after turning the key. However, most children adapt very rapidly to the appliance and the discomfort is very minimal. Remember that the palatal expander should not cause excessive discomfort. If you experience pain or prolonged discomfort then contact your orthodontist immediately.

What are the Pros and Cons of a Palatal Expander?

The palatal expander also has a few pros and cons.

Pros of palatal expander:

  • A palatal expander can help improve jaw asymmetry
  • It can correct misaligned and overcrowded teeth
  • It can improve the airway, breathing, and snoring in children
  • It can help reduce the need for corrective surgery later in life
  • It is compatible with other orthodontic appliances and treatments

Cons of palatal expander:

  • Mild discomfort 
  • Drooling 
  • Lisping
  • Temporary gap between front two teeth

Pre and Post Treatment Photographs

Figure 7: Pre-Treatment Records

Figure 8: Post-Treatment Records

Take Your First Step Today

If you think you or your child has issues with a constricted upper arch, facial asymmetry, snoring, sleep apnea or other health issues then book a free consultation with our orthodontists today to discuss your options.


    1. Grant Breeland; Aylin Aktar; Bhupendra C. Patel. Anatomy, Head and Neck, Mandible. Treasure Island (FL): StatPearls Publishing; 2022 Jan-
    2. Bucci R, D’Antò V, Rongo R, Valletta R, Martina R, Michelotti A. Dental and skeletal effects of palatal expansion techniques: a systematic review of the current evidence from systematic reviews and meta-analyses. J Oral Rehabil. 2016 Jul;43(7):543-64.
    3. Khyati Narula et al. Evaluation of the degree of fusion of midpalatal suture at various stages of cervical vertebrae maturation. 9(4);235-240doi:10.25259/APOS_76_2019
    4. Palate Expander: Uses, Types & Adjusting (clevelandclinic.org)