Firstly, you may question them about their training, experience and qualifications and if they have completed a full-time 3 years postgraduate training program in Orthodontics and not a short weekend course or night time course.
Ask if you brace provider provides other treatments ie fillings, crowns, extractions and dentures as well as Orthodontics? If they do, they are Dentists as Orthodontists only provide Orthodontics.
You can also check if their name is on the Dental Council’s Orthodontic Specialist Register by clicking here