Well, the unfortunate news is that braces can contribute to canker sores. This mainly happens in patients that are already prone to them. They may experience an increase in sores because your mouth is adjusting to a big change when beginning orthodontic treatment. Braces can irritate oral tissue, which leaves it vulnerable to little lesions such as canker sores.
Luckily, avoiding possible triggers and practicing good oral hygiene can help you to avoid or lessen the instances of these sores.