A deep overbite is a dental misalignment where the upper front teeth vertically overlap the lower front teeth when the back teeth are closed. Your upper teeth may cover more than one-third of your lower teeth; in severe instances, the lower teeth might even touch the gum tissue behind the upper front teeth. This vertical overlap is distinct from an overjet, which describes a horizontal protrusion where the upper front teeth extend outward beyond the lower front teeth. While a small degree of overbite, 2-3 millimeters, is considered normal, anything beyond this range indicates a deep overbite.
Underlying Causes of a Deep Overbite
The development of a deep overbite can stem from various factors, categorized as skeletal and genetic influences or developmental and habitual patterns. Skeletal deep bites often arise from an imbalance in jawbone growth, such as a lower jaw that is proportionally smaller or positioned too far back relative to the upper jaw. Genetics play a significant role in determining jaw and tooth shape, contributing to these inherited traits.
Developmental or habitual factors can contribute to or worsen a deep overbite. Prolonged thumb sucking or pacifier use past early childhood can push teeth out of alignment, leading to a dental overbite. Tongue thrusting, where the tongue pushes against the front teeth during swallowing, can similarly influence tooth position. The premature loss of lower back teeth can allow the upper front teeth to over-erupt, exacerbating the vertical overlap.
Potential Complications
An untreated deep overbite can lead to several functional and health issues beyond aesthetics. One common problem is excessive tooth wear, as the improper contact between the upper and lower front teeth can cause enamel to grind down over time. This continuous friction can wear away the biting surfaces of the lower front teeth and the back surfaces of the upper front teeth, potentially exposing sensitive underlying dentin.
Gum and tissue damage represents another concern, especially when the lower front teeth bite directly into the gum tissue behind the upper teeth. This constant irritation can cause pain, inflammation, and even tissue recession or sores. The abnormal bite forces can also strain the temporomandibular joints (TMJ) and surrounding muscles, potentially leading to temporomandibular disorders (TMD). Symptoms of TMD can include jaw pain or soreness, facial pain, headaches, clicking or popping sounds in the jaw, and difficulty chewing.
Aesthetically, a deep overbite may affect facial balance. It can sometimes create the appearance of a shorter lower face or a more prominent chin, influencing the overall facial profile. Addressing these issues early can help prevent their progression and improve both oral health and facial harmony.
Treatment Pathways
Correcting a deep overbite depends on the patient’s age and the underlying cause, and treatment varies. For children and adolescents, treatment is often more straightforward because their jaws are still developing. Orthodontists may use functional appliances, such as Herbst or Twin Block devices, designed to guide the growth of the lower jaw forward and reduce the vertical overlap. Bite plates, either removable or fixed, can also be used to prevent the bite from closing too far, allowing the back teeth to erupt and open the bite. These appliances are frequently followed by traditional braces to precisely align the teeth.
For adult patients, where jaw growth is complete, treatment primarily focuses on repositioning the teeth. Traditional braces or clear aligners, like Invisalign, are common choices to move teeth into their correct positions. This often involves intrusion, where front teeth are gently pushed back into the bone, or extrusion, where back teeth are slightly pulled out, to open the bite and reduce the overlap. Orthodontic treatment in adults aims to achieve a balanced bite and improve oral function.
In cases of severe skeletal discrepancy, particularly in adults, orthognathic (jaw) surgery may be necessary in conjunction with orthodontics. This surgical intervention corrects the underlying jaw misalignment, providing a stable foundation for the teeth. Following any orthodontic treatment, wearing retainers is recommended to maintain the corrected bite and prevent the teeth from shifting back to their original positions.