Tongue Thrust: Breast fed best; if bottle fed, do not enlarge opening for faster feeding and do not feed lying flat so baby must use tongue to prevent too rapid flow of formula into her/his throat.
Airway Problems: If constant & severe mouth breather, have evaluation by ENT doctor.
Crossbite: Have child close mouth normally, you lift up lips, hold out one cheek at a time so you can see the teeth; the upper teeth should overlap (be slightly outside of) the bottom teeth. If any tooth or teeth meet edge to edge or if any lower tooth is outside the upper tooth, this is a crossbite, and if mild, it should be corrected by age 2 1/2 - 3. If severe (all the teeth on one or both sides in crossbite), it should be corrected age 3 - 5 by a rapid palate expander.
Permanent teeth coming in crooked due to crowding: Instead of letting the permanent teeth get fixed in a crooked position in the jaw bone and then require major orthodontics as a teen with the possibility of some relapse back to being crooked later, your dentist should reduce the side of the primary (baby) tooth next to the erupting permanent tooth so it can fit straight into the now larger space. When the next permanent tooth start to come in and needs more space, the next baby tooth is shaved on one side, and so on, until at age 9 when the permanent bicuspids (premolars) erupt the "borrowed" space is regained as the bicuspid teeth are smaller than the baby molars they replace. A dentist who is too lazy to do this for you should not be taking care of children. Much more in the book, including how not to be taken by "the financial arch wire" and how to avoid the 13 common errors in orthdontics.