An underbite is a condition where the lower front teeth are biting in front of the upper teeth.
While it may be due to upper front teeth leaning inwards, it may also be a combination of a smaller upper jaw size and/or larger lower jaw size.
One of the most common causes of an underbite is a smaller upper jaw size. There is a time frame where the upper jaw bones and their connections have not hardened. In this, an underbite can be treated predictably by moving the upper jaw forwards.
The more severe an underbite the better is is to be treated earlier. After this time frame has passed, it is less effective in moving the upper jaw forwards. Treatment is then aimed at addressing any narrow upper jaw that may be present.
In late teens and adults, jaw guidance plates are less effective in correcting jaw problems. Therefore, braces treatment may sometimes be delayed until the jaw has fully grown.
Mild and moderate underbites can still be treated with braces alone. In severe underbites, improvements in one’s smiles and facial appearance are often achieved with a combination of braces or Invisalign and jaw surgery.