Deep bite: when the upper front teeth cover the lower ones
An overlap of about a third is normal. When it becomes more, the wear begins.
When biting down, the upper front teeth normally cover about a third of the lower ones. If they cover more than half, this is called a deep bite; in pronounced cases the lower front teeth bite into the palate.
What follows from it
The lower front teeth rub against the inside of the upper ones – the enamel loses substance, and the teeth become shorter and more sensitive. If they bite into the palate, chronic irritation develops there. In addition, a deep bite restricts the freedom of movement of the lower jaw and can strain the jaw joint.
How it is treated
The front teeth have to move up, or the back teeth have to come further out – usually both, in moderation. During growth this can be controlled well by raising the back teeth; in adults the front teeth are positioned in a targeted way. A fixed brace is usually necessary here, because individual teeth have to be moved vertically – and that is exactly what removable appliances and aligners do worst.
Often in company
A deep bite often occurs together with an increased overbite. Both have the same basis: a lower jaw that sits too far back in relation to the upper jaw.
The key facts at a glance
- An overlap of about a third is normal. More than half counts as a deep bite.
- The lower front teeth rub against the inside of the upper ones – the enamel is lost, and the teeth become shorter.
- In pronounced cases the lower front teeth bite into the palate and irritate it permanently.
- Treatment uses a fixed brace: teeth have to be moved vertically, and that is what aligners do worst.
Answered briefly
Frequently asked questions
Not dangerous, but wearing. The abrasion on the incisors is irreversible; lost enamel does not grow back. The earlier the bite is corrected, the less substance is lost.
Because the lower ones grind along the inner surface of the upper ones when biting. With a deep bite this happens with every swallow – around a thousand times a day. That adds up over the years.
To a limited extent. Lifting the front teeth and bringing the back teeth further out are vertical movements, and that is where aligners are at a disadvantage. Mild deep bites can be treated; pronounced ones as a rule require a fixed brace.
They are two different measurements: the overbite measures to the front, the deep bite downwards. They often occur together because both have the same underlying cause – a lower jaw positioned too far back.