Can there be side effects from orthodontic treatment?

Yes, there can be. The best-known ones are 1) cavities and gum inflammation around the appliances (when brushing is insufficient), 2) root resorption (shortening of the tooth roots), 3) gum recession, and 4) temporary jaw joint discomfort. Most of these can be prevented or caught early with regular checkups and thorough oral hygiene, so it's important not to miss your regular visits, usually every 4-6 weeks, during treatment. If pain or tooth mobility suddenly worsens, please come in even before your scheduled appointment.