It is best for the orthodontist to see children by the age of 7 to advise if orthodontic treatment is required. The first permanent molars and incisors have 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 guide 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 habits, and eliminate abnormal swallowing or speech problems. In other words, early treatment can simplify later treatment.