Fixed appliances are small square brackets bonded to each tooth being moved. These brackets have a horizontal slot for a wire to fit into. This wire is held in place by a ligature. These ligatures are usually made of an elastic material and come in various colors that can be changed at each patient visit. There are also self ligating brackets that do not use an external ligature to hold the main arch wire in and thus offer lower friction.
Brackets can either be composed of stainless steel (metal brackets) or ceramic (clear brackets), which are barely visible. If any brackets fall off during treatment, they can be easily replaced