It is important, that parents notice early habits which can lead to malocclusions, and that they break their children of those habits. Thumbsucking for example, should be stopped by age three, because first the teeth and later the entire jaw bone will adjust to the form of the thumb. This open-sucking bite should be avoided at all cost. However, if it appears, the parents and the dentist should recognize it, so that an expert can be consulted to rule out any subsequent consequences.
 

Consequence of thumbsucking and a severe tongue-problem (see "sample cases")

Further indicative of this problem is the child's breathing. If the child breathes predominantly or only through the mouth, there is not only an increased risk of infection, but the entire development of the nose and throat area can be inhibited, which is the beginning of many toothmalocclusions and jawbone-disorders. Breathing through the mouth can again be caused by limited nasal breathing, weak mouth muscles or malocclusion of the jaw, which can complicate or even prevent lipclosure.
 

Patient with mouthbreathing and incompetent lipclosure.

It can often be difficult for parents to recognize certain malocclusions. That makes the regular checkup at the dentist all the more important, because he or she not only checks for cavities, but also looks for possible orthodontic problems at the jaw and the dental arch. 
 

Photo of normal indentation

Here are a few examples of malocclusions, which can also be detected by a layman.
 
 

Class I The jaws line up correctly, but the teeth are turned, spaced, crooked or crowded.
Class II The upper jaw is too far in front, or the lower is too far back. It´s also called „overbite“.
Class III The lower jaw is too far in front, or the upper jaw is too far back. It´s also called „underbite“.
Open Bite When you bite down with your back teeth, your front teeth stay open.
Closed Bite When you bite down, your upper teeth cover the lower teeth. Sometimes the lower teeth hit the gum tissue behind the upper teeth.
Cross Bite When you bite down, some upper teeth close inside of the lower teeth.