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. In young children, the upper jaw bones and their connections have not hardened. Underbites before the age of 8 can be treated predictably by moving the upper jaw forwards. From 8 to 10 years, baby teeth start to loosen and are less effective in supporting the appliances needed to correct this.
The more severe an underbite the better it is to be treated earlier. After 10 years, early treatment 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 braces, or a combination of braces or aligners and jaw surgery.