It's best for the orthodontist to see children by age 7 to advise if orthodontic treatment is required and the best time for that patient to be treated. The first permanent molars and incisors usually come in by that time and crossbites, crowding and other problems can be evaluated. When treatment is begun early, the orthodontist can guide the growth of the jaw and incoming permanent teeth.
Early treatment can also regulate the width of the upper and lower dental arches, gain space for permanent teeth, avoid the need for permanent tooth extractions, reduce likelihood of impacted permanent teeth, correct thumb-sucking and eliminate abnormal swallowing or speech problems.