Try to use orthodontic wax, Babybel wax or chewing gum to cover the offending part - dry the area first. If the wire is long at the back because it has popped out of the last tube, you can try to re-insert it with tweezers or try to tuck it out of the away under the bracket. If the last metal bracket has broken, the long wire will protrude into the cheek. It can be cut in an emergency or the broken bracket can be re-fixed on the tooth by us. You can try using nail clippers to cut the thinner flexible wires placed in the early stages of treatment. You may need an emergency appointment with us or an emergency dentist. Your brace can be fixed by us at any time after the event.