Twin Block Appliance (Functional Appliance)


The Twin Block appliance is a removable, orthodontic functional appliance that is used to help correct jaw alignment, particularly an underdeveloped lower jaw.  They work by influencing the growth and development of both the upper and lower jaws.  This type of treatment is most effective during a growth spurt.   Therefore, it is important to see an orthodontist early to assess the timing of this treatment to avoid missing out on the growth spurt.  Every person is an individual and everybody’s growth spurt is different.  We recommend seeing an orthodontist from age 7.

The Twin Block appliance is made up of two plates, one for the upper teeth and one for the lower teeth, which work together to bring the lower jaw forward into a better alignment with the upper jaw and creating a improved profile.

The appliance holds the lower jaw forward over a period of time (normally 12 months) until the teeth, jaws and joints have "adapted" and the desired jaw position has been obtained.

The Twin Block can also be modified for other uses such as the expansion of a narrow arch.  This is achieved by incorporating an “expander” in the upper plate, which, over time widens the arch allowing crowded teeth more room.

Twin Block treatment offers noticeable results and therefore a much better profile.  The appliance aligns the jaws but not the teeth, therefore it is considered to be a “first phase” treatment prior to the full orthodontic treatment or braces to align the teeth correctly.

If you are already wearing a Twin Block, you can find further instructions on our patient information page.