Watch for chronic mouth-breathing.
Constant breathing through the mouth can cause the face and jaw to become elongated. Check these four signs to see if your child has any breathing problems:

Watch to see if your child breathes through her mouth.
Check to make sure there is no overlap of upper front teeth to lower front teeth.
Look at your child’s bite. In a normal bite, all the upper teeth rest slightly over the lower teeth when the jaw is closed.
See if the tongue comes between the teeth when your child swallows.

See us by age 7.
The American Association of Orthodontists recommends that children see us by age 7 to help ensure a lifetime of healthy smiles. Some early warning signs that may indicate your child needs orthodontic care include:

Buckteeth Crowded teeth Sideways bite
Teeth coming in the wrong place Breathing through mouth
Thumb-sucking Tongue-thrusting
Difficulty chewing Congenitally missing teeth
TMJ or other joint pain