Nickel, copper and chromium allergy occur in 30% of orthodontic patients with pierced ears, 1-3% of all other orthodontic patients. The symptoms are generally an inflammation of the mouth, and possibly inflammation at points where metal such as a watchband comes in contact with your skin. If you mouth stays sore for more than 2 weeks after you get braces, or if you notice stuffy ears, you probably have an allergy to the metals in your braces.
It has been found that patients sometimes develop sensitivity to nickel, chrome or copper during the orthodontic treatments. Fortunately, a recent article in an allergy magazine Contact Dermatitis 30(1994) 210 suggests that the allergic reaction will go away when your orthodontist switches to nickel, copper or chrome free materials. If you are concerned about nickel, chrome or copper allergies, talk to your orthodontist.