Yes, there are orthodontists who are board-certified by the American Board of Orthodontics. Board-certified orthodontists are known as Diplomates of the American Board of Orthodontics. The only boarding organization for the orthodontic specialty that is recognized by the American Dental Association is the American Board of Orthodontics.
In Canada specialists are certified by the Royal College of Dentists of Canada (RCDC). All specialists in Canada must meet the standards set by the RCDC in order to call themselves specialists.