Skip to main content


Functional appliances are used in growing children, generally between the ages of age of 9 to 12 years. This is usually but not exclusively a form of interceptive orthodontics, which guides the child’s natural skeletal growth and development to better repositioning of the jaws and teeth. 

Functional appliances can be fixed (quad helix or maxillary expander plate or a Forsus spring ), removable plates (twin blocks) or a cherbst appliance. A Reverse pull Headgear may also be worn for correction of underbites due to smaller upper jaws. 

Expansion Plates

If there is a discrepancy in the width/size of the upper and lower jaws, then a palate expander is necessary. A Narrow upper jaw can cause lasting bite problems and can impact physical appearance, with asymmetry in growth of the jaws.

The timing of treatment is important.  For the best result, Orthodontics Australia recommends starting expansion treatment before or during your child’s peak growth spurt – which usually coincides with their teenage years. 

At this stage, the jaw is more malleable and likely to widen. 


To ensure you’re not leaving it too late, we recommend first consulting an orthodontist from age 7 so you can be prepared for all potential outcomes, including early interventions such as Rapid Maxillary Expansion to help minimise future problems. 

These appliances are used to improve the bite, create space for teeth and correct growth discrepancies. Functional appliances are commonly used to improve overall jaw health and alignment, improve our ability to chew, and aesthetics of the teeth. Speak with Dr. Maree top determine if your child could benefit from treatment with a functional appliance.

Contact us for an obligation-free consult