Metal brackets are very strong and can withstand most types of treatment. At first they may irritate your gums, but after a few weeks, when your cheeks get "toughened up" they are not a problem anymore. Most traditional metal braces require an elastic o-shaped rubber band, called a ligature to hold the arch wire onto the bracket. Sometimes orthodontists use metal tie wires (little wires which are twisted around the bracket) in place of elastic ligatures.
