Open Bite vs Crossbite:
Understanding Your Orthodontic Issue

What Exactly Is a "Bad Bite"?

The term malocclusion simply means your teeth don't meet the way they should. Most people know the obvious forms — crowded teeth, wide gaps — but two of the most clinically significant bite problems are open bite and crossbite. These affect not just how you look, but how you chew, speak, breathe, and the long-term health of your teeth and jaw joints.

They're different problems with different causes, different symptoms, and different treatment approaches. Confusing them is common — and costly if it leads to delayed treatment. This guide gives you everything you need to understand both.

Open Bite: What It Is, What It Feels Like

An open bite is a malocclusion where there is no vertical overlap between a set of upper and lower teeth when the jaw is completely closed. In simple terms: you close your mouth fully, but certain teeth are still not touching.

This is more than a cosmetic issue. The teeth that do make contact during an open bite bear an uneven share of all biting and chewing force — which causes accelerated wear, cracks, and sensitivity over time.

The Two Types of Open Bite

Common Signs and Symptoms

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  Visible gap between front teeth When you smile or close your mouth, a noticeable space remains between the upper and lower front teeth.
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  Speech difficulties — especially lisping The tongue has no hard surface to press against for sounds like "s", "z", "sh" — leading to a lisp or altered speech pattern.
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  Difficulty biting through food Biting into a sandwich, apple, or burger requires the front teeth to meet. With an open bite, this is either impossible or requires compensation from other teeth or jaw muscles.
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  Habitual mouth breathing An open bite can prevent the lips from closing naturally, resulting in chronic mouth breathing — with its own set of downstream health effects.
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  Tongue thrust posture In many open bite cases, the tongue rests between the front teeth rather than on the palate — which may have contributed to the open bite in the first place.

What Causes an Open Bite?

Open bites are rarely caused by a single factor. They typically develop from a combination of:

• Prolonged thumb-sucking or dummy/pacifier use — sustained pressure from the thumb or pacifier pushes the front teeth outward and prevents them from descending properly.
• Tongue thrusting — when swallowing, the tongue pushes forward against the front teeth instead of resting on the roof of the mouth. Over time, this consistent pressure tips the teeth apart.
• Skeletal jaw development — in some patients, the upper and lower jaws grow at divergent vertical angles, physically preventing the front teeth from meeting. This is more common in patients with a longer, narrower face shape.
• Mouth breathing habits — chronic mouth breathing alters tongue posture and can affect jaw development, particularly in growing children.
• Genetics — jaw shape and growth patterns are partly inherited. A family history of open bite increases individual risk.

Health Risks of Untreated Open Bite

Many patients are surprised to learn that an open bite — if left untreated — creates compounding problems far beyond cosmetics:

• Accelerated tooth wear — the molars bear all chewing forces, leading to premature wear, fractures, and sensitivity.
• Temporomandibular joint (TMJ) dysfunction — compensating for an uneven bite strains the jaw joints and surrounding muscles, often leading to clicking, popping, or chronic jaw pain.
• Gum disease risk — misaligned teeth are harder to clean, increasing plaque accumulation and the risk of periodontitis.
• Speech and confidence impact — persistent lisping or altered speech can affect social confidence and professional life.

Crossbite: What It Is, What It Feels Like

A crossbite is a lateral misalignment — one or more of your lower teeth sit outside (or in front of) the corresponding upper teeth when you bite. Think of it as the reverse of the natural bite relationship: instead of the upper teeth gently overlapping the lower, the lower teeth close on the outside of the upper ones in one or more spots.

Unlike an open bite, which is immediately visible as a gap, crossbite is often subtler — and sometimes patients don't notice it until a dentist flags it. But the structural and health consequences are significant.

The Two Types of Crossbite

Common Signs and Symptoms

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  Facial asymmetry The jaw shifts to one side when closing — causing asymmetric wear patterns and, over time, a visibly uneven lower face.
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  Jaw pain and clicking (TMJ symptoms) The jaw compensates for the misalignment every time you close your mouth — placing uneven stress on the TMJ. This is one of the leading causes of TMJ disorders in adults.
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  Uneven tooth wear Teeth in crossbite grind against each other abnormally. This wears down enamel on specific teeth — often the inner surfaces — faster than normal.
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  Gum recession on specific teeth Crossbite creates unusual forces at the gumline of affected teeth. Localised gum recession and bone loss are common long-term consequences.
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  Neck and shoulder muscle tension The jaw and cervical spine are mechanically linked. A misaligned jaw can affect head posture and contribute to chronic neck, shoulder, and even upper back tension.

What Causes a Crossbite?

• Narrow upper jaw (maxillary constriction) — the most common skeletal cause. When the upper jaw is too narrow, lower teeth have no choice but to close outside the upper arch.
• Delayed or irregular tooth eruption — baby teeth falling out late or adult teeth erupting in an abnormal position can cause individual tooth crossbites.
• Genetics — jaw width, shape, and the balance between upper and lower jaw size are strongly inherited traits.
• Mouth breathing and low tongue posture — the tongue naturally acts as a scaffold that expands the upper jaw from inside. Chronic mouth breathing disrupts this, allowing the upper arch to narrow.
• Prolonged pacifier or bottle use — similar to open bite, sustained habits during jaw development can affect arch width and bite alignment.

Open Bite vs Crossbite: Side-by-Side Comparison

Now that we've covered both conditions in detail, here's a concise reference you can use to understand the key differences:

How Are These Conditions Diagnosed?

Both open bite and crossbite are diagnosed through a combination of clinical examination and imaging. A proper diagnosis identifies not just what the problem is, but why it exists — which is what determines the right treatment approach.

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   Visual and manual bite examination Your provider will ask you to bite down naturally and assess how your teeth meet — looking at vertical overlap, lateral alignment, and any jaw shift on closure.
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   Dental X-rays (OPG / Bitewing) Panoramic and bitewing X-rays reveal tooth root positions, bone levels, and any impacted or malpositioned teeth contributing to the bite problem.
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   Lateral cephalometric X-ray A side-profile X-ray of the skull that shows the relationship between the upper and lower jaw bones — essential for distinguishing dental from skeletal causes. This determines whether the bite issue originates in the teeth position alone, or in jaw bone growth.
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   3D intraoral scanning Modern digital intraoral scanners create a precise 3D model of your teeth and bite — far more accurate than traditional putty impressions. This scan is the foundation of custom treatment planning.
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   3D digital treatment simulation Using cloud-based orthodontic planning software, your certified provider generates a digital simulation showing planned tooth movements step by step — so both doctor and patient can see the projected outcome before treatment begins.

How Clear Aligners Treat Open Bite and Crossbite

Clear aligners work by applying precise, controlled forces to specific teeth with each tray in a series. For both open bite and crossbite, this means gradually repositioning teeth until the correct bite relationship is achieved. Here's how each condition is addressed:

Treating Open Bite With Clear Aligners

For dental open bite (where the cause is tooth position or habit-related rather than severe skeletal), clear aligners are highly effective. The treatment plan typically involves:

• Intrusion of posterior teeth — in some anterior open bite cases, the back teeth are slightly over-erupted. Aligners can apply intrusive forces to gently push them slightly downward, allowing the front teeth to meet.
• Extrusion of anterior teeth — the front incisors may need to be extended slightly downward to close the gap. This movement requires attachments (small tooth-coloured bumps bonded to specific teeth) to give the aligner the leverage it needs.
• Vertical tooth movement control — clear aligners today offer significantly improved control of vertical tooth movement compared to earlier generations. The multi-layer aligner materials Clear Moves uses (Zendura FLX TPU 3-Layer Molekur Multi-layer) provide the precise, consistent force needed for these movements.
• Habit address — if tongue thrust contributed to the open bite, your orthodontist may prescribe a tongue crib or tongue training alongside aligner therapy to prevent relapse.

Treating Crossbite With Clear Aligners

For dental crossbite — where specific teeth are in reverse position but the underlying jaw width is adequate — clear aligners can correct the misalignment through:

• Torque and tipping movements — affected teeth are tipped or torqued back into the correct arch position using a series of precisely calculated aligner trays with targeted attachments.
• Arch expansion — for mild to moderate cases involving a slightly narrow upper arch, aligners can be used to gradually widen the arch, creating the space needed for teeth to sit correctly inside the lower arch.
• Coordinating upper and lower arch alignment — in crossbite, both arches are planned together to ensure the bite relationship is corrected symmetrically, not just one arch in isolation.

For a deep clinical dive into how crossbite is planned and treated step by step, read our dedicated guide:

When Surgery Is Required

Not every case can be resolved with aligners alone. Clear aligners are a dental tool — they move teeth, but they do not move jaw bones. In cases involving significant skeletal discrepancy (jaw bones that are fundamentally misaligned or mismatched in size), orthognathic surgery may be required alongside orthodontic treatment. Your certified Clear Moves provider will identify this during your diagnosis and refer you appropriately if needed.

When Should You See a Provider?

Both conditions worsen over time if untreated — and both are significantly easier and less expensive to treat in their earlier stages. Here's when to act:

For parents: both open bite and crossbite can often be identified and treated during childhood — when the jaw is still developing and more responsive to intervention. If you notice any of the above signs in a child, early consultation with an orthodontic-certified dentist is strongly advised. Early treatment typically results in simpler, shorter, and more affordable correction.