2 years ago, I was scheduled to get braces. But before that was even planned, my mom took me to a dermatologist- for, you guessed it- allergy testing! I was going to be living two years with strips of metal in my mouth, and I definitely didn't want to be allergic to it! For 2 whole weeks I had to wear a white bandage on my forearm while the testing was going on...I got many questions from people thinking that I had somehow hurt myself! Fortunately that was not the case. Though it turned out that I am allergic to magnesium- interesting, isn't it? That a person can be allergic to metal...Well anyway, magnesium was not an "ingredient" in the braces and I set my appointment. I have now been braces free for almost 4 months now and completely allergy safe!
However strange the idea of getting tested for allergies to braces may seem to outsiders of the "allergy world", it is a natural thought process for anyone with allergies! If anything is going to be in contact with you that you haven't been in contact with before, it is natural to get tested for it, including braces!It may not be something "they" (non-allergic people that is) would ever understand or even think of, but it's important to keep yourself safe! So even though it may seem unlikely that you'll be allergic to it, get tested anyways! As my dad always says "It's better to be safe than sorry!"
Best of Luck!