How Bad Is My Overbite? Severity, Risks, and Treatment

An overbite becomes a clinical concern when the upper front teeth overlap the lower front teeth by more than about 2 to 3 millimeters, which is roughly a third or more of the lower teeth hidden behind the uppers. Most people have some degree of overbite, and a small amount is normal and even desirable for chewing. The real question is where yours falls on the spectrum from cosmetic quirk to functional problem, and that depends on more than just how many millimeters of overlap a ruler would show.

How Dentists Measure and Grade an Overbite

Overbite is measured as the vertical distance the upper incisors overlap the lower incisors when you bite down normally. A reading of 1 to 3 mm is generally considered ideal. Once the overlap exceeds about 4 mm, or the upper teeth cover more than a third of the lower crowns, clinicians start classifying it as a “deep bite.” When the lower teeth touch or dig into the palate behind the upper teeth, the term “closed deep bite” or “complete overbite” applies, and that is where problems concentrate.

Percentage of incisor coverage is another way practitioners describe severity. Covering less than half the lower teeth is mild to moderate. Covering more than half is deep. Complete coverage, where you cannot see the lower incisors at all when you smile with teeth together, is severe. An imaging study using cone-beam CT scans found distinct differences in tooth-root shape and surrounding bone structure in patients with closed deep overbites compared to people with normal bites, which helps explain why the severe end of the spectrum carries different risks than a modest overlap.

1PubMed Central. Evaluation of anterior teeth crown-root morphology and alveolar bone structure in patients with closed deep overbite using cone beam computed tomography

One thing worth knowing: overbite and overjet are not the same measurement, though they often travel together. Overbite is vertical overlap. Overjet is the horizontal gap between the upper and lower front teeth, what people sometimes call “buck teeth.” You can have a deep vertical overbite with minimal overjet, or a large overjet with barely any vertical overlap. Both matter, and both get assessed separately.

What Causes a Deep Overbite

Genetics play the largest role. The size and shape of your jaw, the angle at which it grows, and the position of your teeth on the bone are all heavily inherited. If one or both parents had a deep bite, the odds go up considerably.

Childhood habits can make things worse. Prolonged thumb sucking, for instance, can push the upper incisors forward and alter jaw growth in ways that increase both overjet and overbite. A case report documented a child whose thumb-sucking habit contributed to a Class II malocclusion with an overjet of 9 mm and an open bite in the front, illustrating how the forces from a habit like that can reshape developing bone and teeth in multiple directions at once.

2PubMed Central. Breaking the Thumb Sucking Habit: When Compliance Is Essential

Tooth loss in adulthood can also deepen an existing overbite. When back teeth are lost and not replaced, the bite collapses vertically. The front teeth over-erupt to compensate, and the overbite gets progressively worse over the years. This is a common scenario in middle-aged and older adults who have lost molars to decay or gum disease.

There is also a fascinating evolutionary angle. Research published in Science found that changes in human diet after the Neolithic period, specifically the shift to softer, processed foods, altered the human bite. Earlier populations typically had an edge-to-edge bite where the front teeth met tip to tip. The modern overbite and overjet we consider “normal” are actually a relatively recent development in human history, preserved into adulthood because our jaws no longer wear down the way they did when we were chewing tough, unprocessed food.

3PubMed. Human sound systems are shaped by post-Neolithic changes in bite configuration

Risks to Your Teeth and Gums

A deep overbite puts unusual mechanical stress on the front teeth. The lower incisors can strike the palate or the backs of the upper teeth in ways they were not designed to handle, leading to enamel wear, chipping, and over time, significant tooth damage. A review in the British Dental Journal noted that problems linked to deep overbite include soft tissue trauma, tooth wear, and a lack of space between the upper and lower teeth for restorative work like crowns or veneers.

4British Dental Journal. The restorative management of the deep overbite

That last point is one most people do not think about until they need dental work. If your upper and lower front teeth are nearly touching or overlapping heavily, there is very little room for a dentist to place a crown, a veneer, or even a large filling on a front tooth without the opposing teeth hitting it. Restoring worn or broken front teeth in someone with a deep bite often means the overbite itself has to be addressed first, adding complexity and cost to what might otherwise be straightforward dental treatment.

The bone around the front teeth can also suffer. A study of young men found that those with severe overjet and overbite had measurably less alveolar bone supporting their upper and lower incisors compared to men with normal bites.

5American Journal of Orthodontics and Dentofacial Orthopedics. Severe overjet and overbite reduced alveolar bone height in 19-year-old men

Reduced bone height means the teeth have less structural support, which can become a real problem later in life when age-related bone loss starts compounding the deficit.

In the most severe cases, the lower front teeth can actually dig into the palatal gum tissue behind the upper teeth, a condition called palatal impingement. One long-term evaluation found that about one in five patients with deep bites showed some degree of palatal impingement after decades of living with the condition.

6PubMed Central. Stability of deep-bite correction: A systematic review

Does a Deep Overbite Cause Jaw Pain?

This is where the evidence gets genuinely mixed, and it is worth understanding why. The link between overbite and temporomandibular disorders (the jaw pain, clicking, and headaches often grouped under “TMJ problems”) has been debated for decades.

An older study looking specifically at whether overbite depth alone predicts TMJ symptoms found no differences between people with deep bites and those with normal bites across any of the measures studied. The researchers questioned the role of overbite as an independent cause of jaw dysfunction.

7PubMed. Impact of overbite on indicators of temporomandibular joint dysfunction

But a more recent study that included psychological assessment painted a different picture. In that research, headaches, muscle disorders, disc displacement, and other joint problems all occurred significantly more often in the deep bite group compared to controls. The association was strongest in patients whose deep bite came with upper incisors that tilted backward into the mouth rather than flaring forward. The researchers concluded that a deep bite, especially with that particular tooth angulation, can be a risk factor for TMD.

8European Journal of Orthodontics. Temporomandibular disorders and psychological status in adult patients with a deep bite

What likely explains the discrepancy is that overbite depth alone does not tell the whole story. The direction the teeth lean, whether the jaw is positioned too far back, and individual factors like stress and clenching habits all interact. A deep bite in an otherwise well-aligned jaw may cause few symptoms, while the same depth of overbite combined with a retruded lower jaw and a clenching habit could be a recipe for chronic pain.

Breathing, Airway, and Sleep

When the lower jaw sits significantly behind the upper jaw, the tongue and soft tissues at the back of the throat get pushed into a tighter space. This is the anatomical basis for a potential connection between severe overbite and airway issues. A study using advanced airway imaging and sleep monitoring found that patients with more pronounced jaw discrepancies had roughly a 30% decrease in oropharyngeal volume, and that smaller airway volumes correlated with worse scores on sleep apnea indices.

9PubMed. Assessment of oropharyngeal respiratory volume and sleep apnoea scores using peripheral arterial tonometry may improve diagnosis and treatment planning of combined dysgnathia therapy approaches

The picture in children is less clear-cut. A case-control study of children and adolescents with large horizontal overjets due to an underdeveloped lower jaw found no significant difference in sleep-disordered breathing compared to controls using polygraphy or questionnaires, although the snore index trended higher in the overbite group.

10PubMed Central. Prevalence of sleep-disordered breathing in children and adolescents with large horizontal maxillary overjet due to mandibular retrognathia: a case-control study

So while the airway connection is real in adults with severe skeletal discrepancies, it does not appear to be a reliable red flag in younger patients based on current evidence. If you or your child has a significant overbite and also snores heavily or seems to struggle with sleep quality, it is worth mentioning to your orthodontist, but the overbite alone is not a diagnosis of sleep apnea.

Speech and Eating

Many people assume a deep overbite must interfere with speech, and the reality is more nuanced than expected. An epidemiological study of schoolchildren actually found that a deep overbite had a protective relationship with speech distortion, meaning children with deep bites were less likely to have speech problems compared to those with other types of malocclusion like posterior crossbites.

11PubMed Central. Association between malocclusion, tongue position and speech distortion in mixed-dentition schoolchildren: an epidemiological study

That said, malocclusion in general, including severe overbite, can affect chewing efficiency and has been associated with physical health impacts in broader reviews of the literature.

12PubMed. The impact of malocclusion and its treatment on quality of life: a literature review

If your front teeth do not meet in a functional way, biting through food cleanly becomes harder. People with severe overbites sometimes compensate by tearing food with the side teeth or avoiding certain foods altogether, which is not dangerous but can be socially uncomfortable and nutritionally limiting over time.

The Psychosocial Side

The aesthetic and social consequences of a visible overbite are real and measurable. A study of orthodontic patients found that being bullied was significantly associated with increased overbite and overjet. Bullied participants reported lower self-esteem across multiple dimensions, including social competence, physical appearance, and general self-worth. They also reported higher levels of oral symptoms, functional limitations, and emotional and social impact from their teeth, all adding up to a negative effect on overall oral health-related quality of life.

13PubMed. Bullying in orthodontic patients and its relationship to malocclusion, self-esteem and oral health-related quality of life

This matters because treatment decisions are not purely about millimeters and bone levels. For many patients, especially adolescents, the psychological toll of a prominent overbite is the primary motivator for seeking treatment, and research supports the idea that treatment can significantly improve quality of life in these cases.

Treatment for Children and Adolescents

In growing patients, orthodontists have the advantage of being able to redirect jaw growth rather than just moving teeth. Functional appliances, both removable types like Twin Blocks and fixed types like Herbst appliances, work by positioning the lower jaw forward and encouraging the bone to grow in that direction. A systematic review comparing fixed and removable functional appliances found that both types effectively reduce overjet in children, though the evidence was not strong enough to declare one superior to the other in terms of skeletal or dental effects.

14European Journal of Orthodontics. A comparison of the efficacy of fixed versus removable functional appliances in children with Class II malocclusion: A systematic review

Timing matters. Most orthodontists prefer to start functional appliance treatment during the peak growth spurt, typically around ages 10 to 14. Starting too early can mean a longer overall treatment and the possibility that the child outgrows the initial correction. Starting too late means less growth is available to harness. For overbite specifically, early intervention with a bite plate or similar device can help level the bite while growth is still happening, making later comprehensive treatment with braces or aligners simpler.

Treatment for Adults

Adults with deep overbites do not have the luxury of redirecting growth, so correction relies entirely on moving teeth and, in severe cases, surgically repositioning bone. Traditional braces and clear aligners like Invisalign both work, but they achieve the correction through different mechanics.

A clinical comparison found that conventional fixed braces corrected deep overbite mainly by pushing the lower incisors upward (intruding them by about 1.5 mm) and allowing the back teeth to drop down slightly, which rotated the lower jaw open. Invisalign, by contrast, corrected the same type of deep bite by intruding both upper and lower incisors (about 1 mm and 2 mm respectively) without the molar changes that rotate the jaw.

15American Journal of Orthodontics and Dentofacial Orthopedics. Comparison of clinical outcomes between Invisalign and conventional fixed appliance therapies in adult patients with severe deep overbite treated with nonextraction

Clear aligners have historically been considered less effective for deep bite correction, but the technology has improved. With appropriate attachment designs, bite ramps built into the aligners, and careful staging of tooth movements, aligners can now handle many deep bite cases effectively.

16PubMed Central. Mechanical considerations for deep bite correction with clear aligners

That said, the most severe cases, particularly those involving significant skeletal discrepancy rather than just tooth position, remain better suited to fixed braces or a combined approach.

When Surgery Is Needed

Orthognathic surgery enters the picture when the overbite stems from a jaw size or position problem that teeth alone cannot compensate for. The classic scenario is a lower jaw that is substantially too short or too far back relative to the upper jaw, combined with a deep vertical overlap and reduced lower face height. In these cases, conventional orthodontics alone frequently cannot achieve adequate facial proportions or long-term bite stability.

17American Journal of Orthodontics. Treatment of Class II deep bite by orthodontic and surgical means

Surgery typically involves repositioning the lower jaw forward, the upper jaw upward, or both, depending on where the discrepancy lies. The procedure is done under general anesthesia, requires careful pre-surgical orthodontic preparation to align the teeth within each jaw, and involves a recovery period of several weeks before normal function returns. Cases involving severe deep overbite combined with loss of back teeth and facial deformity are particularly difficult to manage without surgery.

18International Journal of Surgery Case Reports. Two middle-aged cases of deep overbite without molar support treated by orthognathic surgery

Not everyone who qualifies clinically for surgery will have an easy time getting it covered. A study examining medical insurance guidelines for orthognathic surgery found that insurers disqualified patients for three main reasons: no significant jaw deformity on their criteria, no demonstrable health impairment, or the condition’s cause not being a covered benefit.

19PubMed Central. Validity of Medical Insurance Guidelines for Orthognathic Surgery

This means a patient with a severe overbite causing measurable functional problems may still face a coverage denial, making the appeal process and documentation from the surgical team critical.

How Stable Is the Correction Long-Term?

One of the legitimate concerns about deep bite treatment is whether the correction holds. Deep bites are known among orthodontists for their tendency to relapse. A long-term follow-up study tracked patients who had been treated for deep bite and found that about 10% relapsed to 50% or greater incisor overlap at follow-up, though the actual amount of overbite increase in those relapse cases was small. Among all patients who still had a deep bite at follow-up, gum contact and palatal impingement were more common in patients who had been noncompliant with treatment than in those who had genuinely relapsed after adequate correction.

20PubMed. Stability and relapse after orthodontic treatment of deep bite cases-a long-term follow-up study

In practical terms, this means that the vast majority of deep bite corrections do hold up, but retention is critical. Most patients will need long-term or permanent retainers after treatment, and skipping retainer wear is the fastest route to watching your investment unravel. The risk factors for relapse are still not fully understood, which is part of why orthodontists tend to be conservative about retention protocols in these cases.

How AI and Digital Tools Are Changing Assessment

The way overbites are evaluated is starting to shift. A scoping review of recent studies on artificial intelligence in dental malocclusion found that the majority of AI tools used deep learning models for diagnosis and classification, with accuracy rates frequently exceeding 90% for tasks like landmark detection on X-rays and skeletal classification.

21PDXScholar. Applications of Artificial Intelligence in Dental Malocclusion: A Scoping Review of Recent Advances (2020-2025)

Most of this technology is still in clinical and research settings rather than in consumer-facing apps, but the trajectory is clear: automated analysis of dental photographs and X-rays is becoming increasingly reliable, which could eventually make initial screening for overbite severity more accessible and consistent. For now, a clinical exam with calipers and a cephalometric X-ray remain the gold standard for grading how bad your overbite actually is and figuring out whether the problem is in the teeth, the bone, or both.