This type of brace is used in patients who have a problem with a ‘set back’ bottom jaw.

This type of functional appliance is called a twin block appliance. They work by posturing the mandible forwards into a better position. This causes tipping of the upper and lower teeth towards each other, reducing the protrusion of the upper teeth. This type of brace accelerates the growth of the bottom jaw, helping improve the discrepancy between upper and lower jaws.