Metal braces can cause some discomfort in the first few days to a week after getting them put on. Your teeth may feel sore and you may experience some mild irritation of the inside of your lips and cheeks. Orthodontic wax can be placed over your brackets to relieve soft tissue irritation and over-the-counter pain medication can help ease sore teeth. Discomfort typically subsides after the first week as your mouth gets used to your braces.