Twinblock braces are a type of "functional appliance". These are removable appliances which use the muscles of the face and jaws to improve the way that the teeth bite together. They work by positioning the lower jaw in a forward posture which stretches the muscles of the face and helps to correct protruding teeth, improving in most cases the facial profile. They are usually advised in those patients who have very prominent teeth (known as an increased overjet) and with good patient co-operation they can produce dramatic improvements in the way that the teeth bite together. Functional appliances tend to work most effectively in growing patients (children up to the age of about 14 years), so are not used in adult patients.
Although the braces are removable, they usually need to be worn throughout the day and in bed each night in order to work effectively. They are usually only removed when you brush your teeth and when taking part in contact sports or swimming. The treatment time with functional appliances can vary according to how prominent the front teeth are at the beginning of treatment but typically most treatment is completed in 9 to 12 months. Most functional appliance treatment patients then progress onto fixed appliance orthodontic treatment to fully correct their orthodontic problem.