Can braces affect facial development?

Well, it depends. Historically, braces were used to alleviate teeth crowding. However the space to straighten all the teeth had to be created somehow. The traditional method was to extract teeth that were considered "not as functionally important", most commonly premolars. Although, it resulted in a more narrow arch of teeth on the upper and lower jaws. This is especially significant during a child's facial development which grows down and forward. Restricting this growth has been well documented but never focused on since it is contrary to traditional orthodontic treatment still taught in dental schools.