The Twin Block Appliance is used to align the upper and lower jaws of growing children and teenagers so that the jaws come together properly. It can also be used to widen the jaw to prevent overcrowding of teeth, when used with an 'expander' in the upper block.
It works by having a block which is placed into the upper palate (behind the upper teeth) and a second block that fits behind the front lower teeth. When the two parts come together they fit together in a position that corrects the jaw position. Normally the Twin Block Appliance is worn for 9-12 months prior to braces being fitted.
Twin block devices are more comfortable that other treatments since fewer (uncomfortable) wires are involved. Another advantage is that a twin block appliances are easy to remove for sporting activities, although it is recommended that they are worn for at least 18 hours a day. They can be worn safely while asleep. There can be some discomfort and pain when they are first fitted, as well as some initial overproduction of saliva which might last for a week or two.
It is important to keep the device clean, by rinsing it and brushing it with a toothbrush and toothpaste after meals, and cleaning it every few days cleaning in a glass of water (with polident) for around quarter of an hour. Twin blocks need to be checked by your orthodontist every 2-3 months.