Malocclusion, poor jaw development.
What are the real causes?
What Causes Orthodontic Problems
Since the early 1900s, Dr Edward H Angle, the father of modern orthodontics, implicated soft tissue dysfunction and mouth breathing as the cause of malocclusion and poor jaw growth. In the ensuing decades that followed, no system was devised to address these factors and as such, mainstream treatment focused on cosmetic, mechanically driven alteration of the teeth. The assumption was that genetics was to blame, however substantial evidence has been provided that verify Angle's theories.
When a child breathes through the mouth, either during the day or while asleep, the mouth opens and the tongue drops from the roof of the mouth which disrupts the proper development of the upper and lower jaw. In addition to a low tongue posture, other poor myofunctional habits such as a reverse swallow, can also occur as a compensation.
These poor myofunctional habits do not permit the jaws to grow to their full potential and therefore, inadequate room is left for the erupting teeth and this prevents them from emerging into their ideal natural position.
"Of all the various causes of malocclusion, mouth breathing is the most potent, constant and varied in its results." Edward H Angle, The Father of Modern Orthodontics