Twin blocks are a type of functional orthodontic appliance used to correct large overbites. They are named “twin” blocks because they consist of two separate plates, one for the upper teeth and one for the lower teeth, that work together to reposition the jaw and teeth.
After the teeth have been scanned, the Twin Blocks are custom-made in a dental laboratory to fit your teeth. The upper and lower plates each have a block of acrylic that guides the lower teeth and jaw into an improved forward position.
Twin blocks need to be worn day and night and are just removed for eating, cleaning, and contact sports. They are typically worn for 9-12 months and require adjusting every 8 weeks or so by your orthodontist to ensure that they are working effectively. Wearing Twin Blocks isn’t easy at first and will take some adjusting to them. Some discomfort and speech problems during the first week or two is completely normal. This gets easier with time and practice wearing them.
Twin blocks work best in growing patients, so an overbite must be identified and managed well before the end of the adolescent growth spurt, and ideally much earlier. Correction of an overbite with Twin Blocks is usually followed by a period of time with fixed braces to complete alignment of the teeth and perfect the bite.