What Is an Open Bite and How Is It Corrected?
When the Teeth Don't Meet
Most people assume that when the mouth is closed, all the teeth come together. For patients with an open bite, that's not what happens. Despite the mouth being fully closed, a gap remains between the upper and lower teeth — leaving them visibly separated even when the jaw is shut.
It is one of the more striking dental presentations Dr Gray sees at Dr Gray Dentistry in Durban — and one that patients frequently describe as something they have been self-conscious about for years without fully understanding what caused it or whether it could be fixed.
The reassuring answer is that open bites can be corrected — and in many cases, particularly when identified during childhood, the correction is more straightforward than patients expect.
What Exactly Is an Open Bite?
An open bite is a bite discrepancy where the upper and lower teeth do not make contact when the mouth is closed. The gap can occur at the front of the mouth — an anterior open bite — or less commonly at the back — a posterior open bite.
Anterior open bite is by far the more common presentation. The back teeth meet normally but the front teeth — incisors and canines — do not touch. There is a visible vertical gap between the upper and lower front teeth when the jaw is closed. This is the presentation most people picture when they think of an open bite.
Posterior open bite is less common and typically involves a gap between the back teeth on one or both sides, with the front teeth meeting normally or overlapping. This presentation is less visually obvious but can significantly affect chewing efficiency and jaw function.
What Causes an Open Bite?
Open bites develop through a combination of skeletal, dental, and habit-related factors — and understanding which is driving the problem in any individual patient is essential for choosing the right correction.
Thumb sucking and dummy use
Prolonged thumb sucking is one of the most well-established causes of anterior open bite in children. When a thumb or dummy is placed between the teeth for extended periods — particularly during the years when the permanent teeth are erupting — the continuous presence of the digit or appliance physically prevents the front teeth from erupting fully and pushes them apart. The result is a gap that reflects the shape and position of the thumb.
This cause is highly relevant to timing. Thumb sucking that stops before the permanent teeth erupt rarely causes lasting open bite. Thumb sucking that continues into the years when permanent teeth are coming through creates a progressively established open bite that becomes more complex to correct the longer it persists. This is why habit appliances like tongue gates — which Dr Gray fits at Dr Gray Dentistry — are most effective when placed early.
Tongue thrust
Tongue thrust — a swallowing pattern where the tongue pushes forward between the upper and lower teeth during swallowing — is both a cause and a consequence of anterior open bite. In patients with a tongue thrust habit, the repeated forward pressure of the tongue during every swallow applies a sustained outward force on the front teeth, preventing them from meeting and maintaining the gap once it has formed.
Tongue thrust is one of the reasons open bite can be stubborn to correct and prone to relapse — because even after the teeth have been moved into contact, if the tongue thrust habit is not addressed, the tongue continues applying force that pushes the teeth apart again.
Skeletal jaw pattern
Some open bites are primarily skeletal in origin — meaning the underlying jaw structure, rather than a habit or tooth position, is the root cause. Patients with a skeletal open bite typically have a jaw that grows in a more vertical direction than normal — causing the back of the jaws to be further apart than the front, and producing a bite where the front teeth cannot reach each other even though each tooth individually is in a reasonable position.
Skeletal open bites are generally more complex to treat than dental open bites, and in severe cases may require a combined orthodontic and surgical approach to achieve a stable correction. Identifying the skeletal contribution to an open bite early — particularly during childhood when jaw growth can still be guided — is one of the most important reasons for early orthodontic assessment.
Mouth breathing
As discussed in the airway posts in this series, mouth breathing affects jaw development in ways that can contribute to open bite. When the tongue rests in a low position — as it does in mouth breathers — rather than against the palate, the normal developmental pressure that shapes the upper jaw is absent. The resulting narrow, high-arched palate and altered jaw growth pattern can contribute to an anterior open bite.
Previous dental treatment
In some adults, open bite develops or worsens following significant loss of back teeth — where the reduced support of the back teeth allows the jaw to over-close in the posterior region, creating a relative open bite at the front.
How Does an Open Bite Affect Daily Life?
Beyond the aesthetic concern, an open bite has genuine functional consequences that motivate many patients to seek treatment:
Difficulty biting food
The front teeth — incisors — are designed for biting and tearing food. When they don't meet, this function is lost. Patients with anterior open bites often find it difficult or impossible to bite into foods like sandwiches, pizza, or fruit — relying entirely on their back teeth for all chewing. Over time this places excessive load on the back teeth and can contribute to wear and jaw strain.
Speech difficulties
The front teeth play an important role in the production of certain sounds — particularly sounds that require the tongue to contact or approach the upper front teeth, such as 's', 'z', 'th', and 'f'. An anterior open bite creates a space through which air escapes during these sounds, producing a lisp or whistling quality that patients are often very conscious of in social and professional situations.
Jaw strain and TMJ implications
The compensatory chewing patterns that develop in response to an open bite — relying heavily on the back teeth, adopting asymmetric chewing habits, or thrusting the jaw forward to bring teeth into contact — can place significant strain on the jaw muscles and TMJ over time. Open bite is one of the bite presentations that Dr Gray specifically assesses in TMJ patients at Dr Gray Dentistry, because the two conditions frequently coexist and interact.
Aesthetic and confidence impact
For many patients, the visible gap between the front teeth — particularly when smiling or speaking — has a significant impact on self-confidence. This is frequently the primary motivation for seeking treatment, and there is nothing superficial about it — how a person feels about their smile directly affects how freely and confidently they engage with the world.
How Is an Open Bite Corrected?
The right correction depends on what is causing the open bite, how severe it is, and whether the patient is still growing. Dr Gray assesses all of these factors at Dr Gray Dentistry before recommending a treatment approach.
Habit elimination — for children
Where thumb sucking or tongue thrust is the primary cause, the first priority is eliminating the habit before attempting any tooth movement. A tongue gate — a fixed appliance that physically blocks thumb placement — is highly effective at breaking the thumb sucking habit in children, often within a few weeks of fitting. Once the habit is eliminated, mild open bites in growing children sometimes partially self-correct as the freed teeth erupt into contact.
For tongue thrust, myofunctional therapy — exercises that retrain the swallowing pattern and tongue resting posture — is an important adjunct to orthodontic treatment. Without addressing the tongue thrust, orthodontic correction of the open bite is at significantly higher risk of relapse.
Orthodontic treatment with braces
For dental open bites — where the primary issue is tooth position rather than skeletal jaw structure — fixed braces are the most effective correction tool. Specific mechanics are used to intrude the back teeth and extrude the front teeth simultaneously, gradually closing the gap by moving teeth toward each other in the vertical plane.
Vertical elastics — rubber bands worn between specific upper and lower front teeth — are frequently used to assist with front tooth extrusion during treatment. As with all elastic wear, consistency is essential. Dr Gray monitors progress carefully at each adjustment appointment and adapts the mechanics as the open bite closes.
Palatal expanders
Where a narrow upper arch and mouth breathing are contributing to the open bite — as is common in children — palatal expansion addresses the underlying jaw development issue and creates a better environment for the teeth to meet. Expansion is most effective during the growth years when the palatal suture remains flexible.
Clear aligners
Clear aligners can be used to correct mild to moderate anterior open bites in adults where the skeletal component is minimal. They are generally less effective for open bite correction than fixed braces — particularly for more significant vertical discrepancies — and Dr Gray assesses whether aligners are a suitable option on a case-by-case basis.
Surgical correction — for severe skeletal open bites
Where the open bite is primarily skeletal — driven by the jaw structure rather than tooth position — and the discrepancy is significant, orthognathic surgery combined with orthodontic treatment may be the only way to achieve a stable, lasting correction. Dr Gray identifies cases where surgical involvement is likely at the assessment stage and refers to an oral and maxillofacial surgeon where appropriate.
Why Relapse Is a Concern — and How It Is Managed
Open bite has a higher relapse tendency than most other bite corrections — meaning that without careful retention planning and habit management, the gap has a tendency to reopen after treatment.
The primary reasons for relapse are persistent tongue thrust and insufficient retention. This is why Dr Gray places particular emphasis on retainer wear after open bite correction — often recommending fixed retainers bonded behind the front teeth to provide continuous retention — and why addressing tongue thrust habits before and during treatment is so important.
Patients who complete open bite correction with excellent retainer compliance and resolved tongue habits maintain their results well. Those who are inconsistent with retention are at significantly higher risk of seeing the gap reopen over time.
Correct Your Open Bite at Dr Gray Dentistry, Durban
Whether you've had an open bite since childhood or have noticed your bite changing over time, a thorough assessment with Dr Gray at Dr Gray Dentistry in Durban, South Africa is the right starting point. Dr Gray will assess the cause, the severity, and the most appropriate correction for your specific situation — giving you a clear, honest picture of what treatment involves and what you can realistically expect.
Book your orthodontic assessment at Dr Gray Dentistry in Durban today.