According to the American Association of Orthodontists all children should have an orthodontic screening by no later than age 7.

Influence jaw growth in a positive manner
Improve the width of the smile
Reduce the need to extract permanent teeth
Reduce or eliminate the need for jaw surgery

Correct harmful oral habits
Improve aesthetics and self-esteem
Guide permanent teeth into more favorable positions
Reduce likelihood of impacted permanent teeth

Improve lip posture
Preserve or gain space for erupting permanent teeth
Reduce potential for damage to TM joints
Lower the risk of trauma to protruded front teeth

Encourage better compliance before the uncooperative teenage years
Simplify and shorten treatment time for later orthodontic treatment
Increase stability of final treatment results