An open bite is a form of malocclusion defined by a lack of vertical overlap between the upper and lower teeth when the mouth is closed. This condition prevents the teeth from meeting, leaving a noticeable gap that can impair chewing and speech function. A variety of treatment approaches exist to successfully close this space and establish a stable bite. Treatment success often depends on accurately determining the underlying cause of the jaw or tooth misalignment.
What Exactly is an Open Bite
An open bite is a condition where a gap remains between the dental arches even when the jaw is fully closed, preventing the upper and lower teeth from making contact. This malocclusion is broadly categorized by the location of the gap: anterior and posterior. An anterior open bite, the more common form, occurs when the front teeth do not overlap vertically, leaving an opening at the front of the mouth.
A posterior open bite occurs when the back teeth, such as molars and premolars, do not meet, leaving contact only between the front teeth. Both types significantly interfere with the ability to bite, chew, and speak clearly. The causes of this condition are generally split into two main categories: skeletal and dental/habitual.
A skeletal open bite results from discrepancies in jaw growth, often due to a hyperdivergent pattern where the lower jaw grows downward and backward. In contrast, a dental or habitual open bite stems from environmental factors that push the teeth out of alignment. These factors include prolonged thumb or finger sucking, extended pacifier use, or a persistent tongue thrust, where the tongue pushes against the front teeth during swallowing.
Braces Alone: When They Work and When They Don’t
Braces can be an effective treatment for an open bite, particularly when the condition is mild or primarily caused by dental or habitual factors rather than a severe jaw discrepancy. To close the open bite, the orthodontic mechanism involves the vertical movement of teeth, specifically the extrusion of the front teeth to bring them into contact.
For younger patients whose jaw growth plates are still active, braces can guide the eruption of permanent teeth and modify minor growth patterns, leading to successful closure. The treatment often utilizes specific archwire bends and the strategic use of elastic rubber bands to pull the upper and lower teeth toward one another. This approach is sufficient when the vertical gap is small and the underlying skeletal structure is relatively balanced.
However, braces alone are usually insufficient for moderate to severe open bites, especially those resulting from a significant underlying skeletal discrepancy. In these cases, fixed appliances do not address the fundamental issue of disproportionate jaw alignment. Attempting to correct a severe skeletal open bite with braces alone risks instability, potential root damage, and a high likelihood of relapse. For these complex cases, specialized adjunctive therapies are required to achieve a stable and functional correction.
Necessary Treatments Beyond Standard Braces
When the open bite is due to underlying skeletal issues or persistent oral habits, treatments must go beyond simple tooth movement with fixed braces. Addressing soft tissue habits, such as tongue thrusting, is often the first step since it is a significant cause of anterior open bites. This is done using a habit-breaking appliance, like a tongue crib, which is a small, fixed wire cage placed behind the front teeth to physically block the tongue from pushing the teeth outward.
For moderate skeletal open bites, Temporary Anchorage Devices (TADs) can help patients avoid jaw surgery. These are small, biocompatible titanium mini-screws temporarily placed into the bone to act as a fixed anchor point. TADs allow the orthodontist to apply strong, controlled forces to intrude, or push up, the back molar teeth. Intrusion of the posterior teeth causes the lower jaw to rotate forward and upward, effectively closing the vertical gap.
In the most severe cases of skeletal open bite, where the jaw alignment is significantly misaligned, orthognathic surgery is necessary. This procedure involves surgically repositioning the upper and/or lower jaw to achieve a correct and stable relationship between the dental arches. The surgery is always combined with a period of orthodontic treatment to align the teeth precisely before and after the skeletal correction.
Maintaining Correction After Treatment
Maintaining the corrected bite after the active phase of orthodontic treatment is particularly challenging for open bite cases. The primary goal of the retention phase is to prevent the teeth from shifting back, especially since the forces that created the open bite, such as tongue pressure or continued growth, may still be present. Studies have reported relapse rates as high as 25% to 38% in cases treated conventionally.
To counteract this, the retention protocol must be strict and often long-term, sometimes requiring lifetime wear. Both fixed and removable retainers are used, but fixed retainers—thin wires bonded directly to the back surfaces of the front teeth—are considered more effective for maintaining the vertical correction. The fixed retainer ensures the front teeth remain in contact and resists the outward pressure from the tongue.
Successful long-term stability also relies on fully resolving any contributing soft tissue habits, such as tongue thrusting. Habit correction and myofunctional therapy are often integrated into the treatment plan for this reason. If the underlying muscular imbalance is not corrected, the tongue can continue to exert pressure, eventually forcing the teeth apart and compromising the result.