Your child may feel a little sore when treatment first starts. This is usually due to the teeth being moved. Usually, this will last about 24 to 72 hours.
They may also feel pain when their braces get adjusted or tightened. Also, they might get mouth sores due to the braces rubbing against the inside of their mouth. If this happens, have them rinse out their mouth with a saltwater solution which will help them heal faster.
Normally, they will feel less discomfort or pain as they progress along their treatment. If they really feel uncomfortable, you can try pain medicine such as Tylenol (or any acetaminophen) or Advil (or any ibuprofen).