Functional Appliances

Functional orthodontics uses removable intra-oral appliances. They use the muscles of the face and jaws to improve the way that the teeth bite and align together. These appliances are generally used before fixed appliances (brackets) to reduce the discrepancy between the upper and lower jaws, and teeth. They use the natural growth potential of the patient to affect change, so they tend to work most effectively with growing patients and are therefore not used in adult patients.

These appliances can be used to treat problems with the position of the upper jaw and lower jaws and teeth. Your functional brace will help to correct your bite so that your teeth are alignned properly.

There are a number of functional appliances that can be used. We mainly use the Twin Block appliances. Twin Blocks are jaw aligning powerful braces that can reduce an over-jet in a young children and teenagers.

  • Twin Block appliances are used in the growth phase to treat an underdeveloped lower jaw. It is usually a ‘phase 1’ type appliance and is followed by fixed braces (phase 2) or a retainer.
  • The Twin Block appliances are made from acrylic using two plastic blocks on the top jaw and two on the bottom jaw. The appliance postures a patient’s lower jaw into a forward position on closing their mouth. The forces of occlusion are used as the functional mechanism to correct the malocclusion and aid lower jaw growth.
  • The Twin Block is a removable functional appliance worn full-time for 9-12 months.
  • Mainly the upper and occasionally the lower plate may include an expansion screw to widen the arch.

Most people need to wear them all the time. However, it is important to follow your orthodontist’s instructions about how and when to wear the appliances, as success in treatment is dependent on your full co-operation in wearing the brace. Parts must be worn together in the correct position or the brace will not work.

Treatment can take anywhere between six to twelve months and may be followed by a course of fixed braces.

These appliances are also applicable for many patients with less severe problems.

Tips for wearing function appliances:

  1. Wear the brace full-time. If you have any problems wearing the brace, contact us immediately.
  2. Take the brace out for cleaning your teeth, contact sport, and swimming.
  3. It is possible, but not essential, to wear your appliance at meal times. This requires a little practice, but is worth the effort.
  4. Sore spots will usually pass with continued use of the appliance. If discomfort persists, contact us for advice or for an appointment as soon as possible.
  5. You may produce a little more saliva at first, but this will soon return to normal.
  6. We know… Speaking is usually the biggest problem that our patients have with functional appliances. Practice reading out loud at home but avoid constantly removing your brace. You’ll learn to speak wearing your brace in no time! Do advise friends, family, and teachers that you have a new brace and are learning how to speak again.
  7. Ensure you keep the brace very clean. Brush it thoroughly with a toothbrush and soak the brace in ‘ brite retainer’ two to three times a week.
  8. When not using the appliance, ensure you store it in the box provided and take good care of it. As you know, they are expensive and you may have to pay for a replacement.
  9. Whatever you do, avoid wrapping your functional appliance in tissue paper. Most braces that are thrown away have been wrapped in a napkin at lunchtime!

If your brace breaks or becomes distorted, contact the practice immediately.

Do You Have any other questions? Call us on 02072241402 or email us on