Orthodontic treatment isn’t very age-specific; young kids and adults alike can get them mostly for the reason of misaligned, crowded, or overlapping bites. In younger kids, malocclusion can happen for a number of reasons, like consistent thumb-sucking, and when children lose baby teeth a bit too soon.
Kids can go to the dentist can go at any age for a consultation for their orthodontic treatment, but that doesn’t mean they will get braces right away. The dentist will simply check for any signs of malocclusion and determine what’s the best age to get their braces. Most dentists would recommend the age of 7, when the permanent teeth start erupting and when malocclusion becomes more apparent.