Blog Hero

What Is a Functional Appliance in Orthodontics?

Book Appointment
Close up photo of a woman's smile showing her wearing an orthodontic retainer.

What Is a Functional Appliance in Orthodontics?

Functional Appliances in Orthodontics

When most people hear orthodontics, they probably think of braces. However, multiple orthodontics services are available to help support your smile and oral health. You’ve likely heard that Invisalign is an alternative to braces, but most patients are unfamiliar with the benefits of functional appliances.

So what are functional appliances, and who can they benefit?

What Can Functional Appliances Do?

Functional appliances can help correct various types of oral issues. Like retainers, most functional appliances are removable. Functional appliances can be the sole treatment or used in combination without orthodontic treatment, including braces. 

Removable appliances can be less precise compared to braces. They promote jaw positioning and help control jaw growth. Functional appliances are also beneficial when moving a group of teeth or a single tooth.

In some cases, using a functional appliance can reduce the number of years a patient may need to wear braces. In some instances, functional appliances may be worn with braces simultaneously. Additionally, as functional appliances are removable, they can be more convenient than braces, including fewer food restrictions

Some oral issues functional appliances can help correct include:

Crowded Teeth

Crowded or misaligned teeth can be minor or significant. Minor overlaps may not interfere with chewing or comfort. However, severe overcrowding or misalignment can lead to chewing issues, excess wear on teeth, gum disease, and speech difficulties. 


A crossbite is when the upper teeth don’t align with the lower teeth. For example, your 2 front teeth don’t line up with your bottom front teeth. A crossbite can increase the risk of multiple issues, including:

An overbite or overjet is colloquially known as buck teeth because the upper front teeth stick out. An overbite is different from a deep bite, where the front teeth overlap in front of the bottom teeth.

Some problems associated with a severe overbite include:

  • Breathing issues
  • Chewing difficulties
  • Damage to teeth or gums
  • Speech impediments

Orthodontic Functional Appliance Examples

There are many orthodontic appliances, from removable acrylic appliances to elastics. Your orthodontist will explain any recommended device when an appliance can benefit your oral function and health. Common examples include bite blocks, palate expanders, tongue tamers, and spacers.

Bite Blocks

Bite blocks (also bite turbos or ramps) prevent your upper and lower teeth from touching. The tiny devices are usually L-shaped or triangular and are sometimes spring-loaded. Bite blocks can be used alone to improve alignment or with braces. In addition to helping correct bite misalignment, they also prevent patients from accidentally biting down on a braces bracket.

The devices are placed on the tongue side of your teeth and are attached to the back molars. Bite blocks are commonly acrylic or metal and are available in various colours, including tooth-coloured ones.

A dentist holds a cast with an installed palate expander.

Palate Expander

When a child has a narrow palate, it can lead to multiple dental issues, such as a crossbite, tooth crowding, or impacted teeth. A palate expander can prevent some of these issues by widening the child’s upper jaw (the maxilla), allowing more space for teeth to grow and align correctly. 

A palate expander can be fixed or removable. The appliance attaches to the upper arch. The palate expander is held in place with bands around the teeth or a plastic material that is bonded over certain teeth. A key is used to widen the expander incrementally. 

Your orthodontist will recommend how often to turn the key and how much. The rate of palate expansion and how much increase is necessary depends on the patient’s needs. 

Tongue Tamers

A tongue tamer or tongue crib is an auxiliary appliance used to help break the bad habit of tongue thrusting. When the tongue pushes against the teeth (instead of the roof of the mouth), the pressure can move the teeth outward. The condition is commonly treated in children to prevent the development of oral issues, including:

  • Ankyloglossia (tongue-tie)
  • An open bite
  • Poor swallowing habits
  • Speech impediments 

The tongue tamer guides the tongue’s movements with metal bars behind the front teeth. The appliance attaches to the top molars with a wire, then along the inside top of the teeth. 


As the name implies, orthodontic spacers add space between teeth. Your orthodontist may use spacers to prepare your teeth before braces. The spacers (or separators) are inserted between teeth, typically molars, so they can later attach braces around those teeth.

Can Adults Do Functional Orthodontics?

Orthodontics can benefit oral health and function at any age. Notably, functional appliances are usually worn by younger patients as they’re still developing. Since they’re still growing, it can be easier to guide changes. 

Functional appliances are generally recommended for children younger than 13. However, adults can benefit from certain functional appliances.

Boost Your Smile with Appliances

There are many orthodontic options for improving your smile. Functional appliances can be an effective option when orthodontic concerns are diagnosed early. 

Our team at Fairlawn Dental Centre can assess if functional appliances are a good fit for your child’s oral health. Please don’t hesitate to contact us to learn more about functional appliances.

We love supporting our youngest patients’ oral health and helping them feel confident about their smiles. Book an appointment today!

Dr. Ferhana Jaleel

Written by Dr. Ferhana Jaleel

As a dentist in the Ottawa area Dr. Ferhana Jaleel has been practicing full-time general dentistry over 25 years and expertly cares for patients of all ages.

To ensure that she provides patients with the best quality and most advanced care, she continually upgrades her knowledge and skills. This continued education covers topics on cosmetic and reconstructive periodontal surgery, aesthetics including Lumineers®, orthodontics, Invisalign®, placement and restoration of dental implants, and many others.

More Articles By Dr. Ferhana Jaleel

Our Services

Dental Implants

Family Dentistry

Sedation Dentistry

Emergency Dental Care

Our Location

Find us on Carling Avenue across the corner from Carlingwood Mall. For your convenience, we offer free parking and easy access to transportation.

Our Address

  • 2194 Carling Avenue, Unit 1
  • Ottawa, ON K2A 1H3

Contact Us

Our Google Reviews

instagram facebook facebook2 pinterest twitter google-plus google linkedin2 yelp youtube phone location calendar share2 link star-full star star-half chevron-right chevron-left chevron-down chevron-up envelope fax