A deep bite, also known as an excessive overbite, is a common dental misalignment where the upper front teeth significantly overlap the lower front teeth. This condition can impact how the teeth and jaws function together.
What is a Deep Bite?
A deep bite is a type of malocclusion characterized by an excessive vertical overlap of the upper front teeth over the lower front teeth when the back teeth are closed. In a healthy bite, the upper front teeth typically cover the lower front teeth by about 1 to 2 millimeters, or approximately 30-40% of the lower incisor height. With a deep bite, this overlap is much greater, sometimes to the extent that the upper teeth completely hide the lower front teeth or even bite into the gum tissue behind them. This condition is distinct from an overjet, which refers to the horizontal protrusion of the upper front teeth.
Why Do Deep Bites Occur?
Deep bites can develop due to a combination of genetic and acquired factors. Genetic predispositions, such as inherited jaw size and shape, can influence tooth alignment. For example, a smaller lower jaw can lead to the upper teeth protruding further.
Skeletal growth patterns also contribute. Imbalances in jaw growth, like an underdeveloped lower jaw, can cause excessive overlap. Certain habits during childhood, like prolonged thumb-sucking or pacifier use, can influence jaw development and tooth position. Additionally, the loss of posterior teeth can result in a deep bite, as the absence of back tooth support allows the jaw to over-close, causing the front teeth to overlap more.
What Problems Can a Deep Bite Cause?
Deep bites can lead to several complications. One common issue is excessive wear on tooth surfaces, particularly on the lower front teeth and the back of the upper front teeth. This wear can lead to sensitivity, chipping, cracking, and may require restorative dental procedures.
The significant overlap can also damage gum tissue. When the upper teeth bite too far down, they can press into the gum tissue behind the lower front teeth, causing irritation, inflammation, and gum recession. The lower teeth might also bite into the roof of the mouth, leading to sores. These issues increase the risk of gum disease.
A deep bite can also contribute to temporomandibular joint (TMJ) disorders. The misalignment places stress on the jaw joints, potentially causing pain, discomfort, clicking, and headaches. This strain can affect jaw muscles, leading to soreness and difficulty with movement. Individuals with a deep bite may also experience difficulties with chewing and biting, as the excessive overlap can interfere with proper food breakdown. Speech impediments and aesthetic concerns, such as a shortened facial appearance, can also arise.
How Are Deep Bites Corrected?
Correcting a deep bite often involves orthodontic treatment, with the specific approach depending on the severity of the condition and the patient’s age. Braces are a common and effective method, using brackets and wires to gradually reposition teeth and achieve proper bite alignment. Clear aligners, like Invisalign, offer a discreet alternative, using custom-made, removable trays to shift teeth.
Specialized orthodontic appliances may also be used. Bite plates, for example, can help separate the back teeth, allowing for changes in bite depth. For younger patients, functional appliances like Herbst or Andresen appliances can guide jaw development to address skeletal imbalances. In some instances, a palatal expander might be employed to widen the upper jaw, creating more space for proper alignment.
For severe deep bites, especially in adults where jaw growth is complete, orthognathic surgery may reposition jaw bones. This often works with orthodontic treatment. If tooth wear has occurred, restorative dental work, such as crowns or implants, may be necessary after correction to rebuild damaged teeth and establish a functional bite. The overall goal of correction is to achieve a balanced and healthy bite, preventing further complications.