Braces stay on your teeth because of a few different ways to attach different parts of braces. First, the brackets are bonded on with a special "cement" after the teeth are cleaned with something that tastes like lemon juice. The cement is hardened using UV light. the Then, on your molars, molar bands are sometimes placed around those teeth to help keep braces in place. Finally, there is a wire that attaches to the brackets and molar bands. The wire is held in place using small rubber bands that go around the brackets and also the wire is slipped through the molar brackets .
Dentists use a special adhesive that's activated by UV rays to hold the brackets to the teeth. But they use another special adhesive that drys just like glue to the teeth in order to hold the actual braces onto the teeth. Hope that helps!