What causes the bite problems in the first place?

The mouth and dentition develop under the combined influence of both genetic inheritance and acquired environmental factors.

Genetics undoubtedly has a role. How else do people look like their parents? The influence can be remarkably detailed; for example, identical twins often have the exact same tooth that is twisted, in the same direction, and by a similar amount. Inherited factors control the size of the teeth, extra or missing teeth and some jaw growth problems.

Acquired or environmental factors modify the way in which the jaws and dentition develop. Examples include thumb or finger sucking, mouth breathing, some types of tongue posture and behaviour, and the previous loss of teeth because of decay or accidents. However, some of these may also be subject to genetic control such as tongue size and posture.