Crossbite in Adults: Treatment Options, Braces vs. Aligners

Treating a crossbite in an adult is fundamentally different—and mechanically more demanding—than treating it in a child.

While children can easily expand their upper jaw with a simple palatal expander, adult bones require sophisticated orthodontic camouflage or surgical intervention. Let’s explore the clinical reality of fixing a transverse deficiency in a mature skeleton.

What Is a Crossbite?

In a healthy bite, the upper teeth should sit slightly outside the lower teeth, much like the lid of a box fitting over its base. A crossbite occurs when some of the upper teeth sit inside the lower teeth.

• Anterior Crossbite: Involves the front teeth (similar to an underbite, but typically involving only one or two teeth).
• Posterior Crossbite: Involves the back molars. The upper jaw is too narrow, causing the upper back teeth to bite inside the lower back teeth.
• Unilateral vs. Bilateral: It can happen on just one side of the mouth (unilateral) causing the jaw to shift to one side, or on both sides simultaneously (bilateral).

Like open bites, crossbites must be diagnosed as either Dental (misaligned teeth) or Skeletal (misaligned jawbones).

Why Crossbites Are More Challenging After Age 18

If your orthodontist seems cautious about your treatment timeline, it is due to basic human anatomy:

• Growth Plates are Closed: The midpalatal suture (the line down the middle of the roof of your mouth) fuses solidly during late puberty. A non-surgical expander cannot break this fused bone in an adult.
• Limited Natural Expansion: Attempting to widen the smile purely by pushing the teeth outward (without widening the bone) can push the tooth roots right out of the gums, causing severe recession and bone loss.
• Higher Relapse Risk: Adult teeth have deep “muscle memory.” Transverse (width) corrections have a very high tendency to relapse if retainers are not worn strictly.
• Bone Density Differences: Adult bone is denser, meaning teeth move slower and require carefully calibrated, continuous forces.

Causes of Crossbite

Adult Treatment Options: The Clinical Arsenal

Depending on the severity, orthodontists use three primary methods to treat adults:

1. Traditional Braces

Braces are excellent for dental crossbites. They use thick, expanded archwires to gently flare the upper teeth outward and the lower teeth inward. Treatment often involves cross-elastics (rubber bands stretching from the inside of the upper teeth to the outside of the lower teeth) to pull the bite into alignment. Braces offer the necessary 3D root torque to move the teeth safely within the adult bone limits.

2. Clear Aligners

Clear aligners can handle mild dental crossbites by programmed tipping of the crowns. They require heavy composite attachments to grip the teeth and precision cuts to allow for cross-elastics. However, they struggle with massive transverse expansion because plastic flexes under heavy loads.

3. Surgical-Assisted Rapid Palatal Expansion (SARPE)

For severe skeletal crossbites where the upper jaw is physically too narrow, orthodontic camouflage will fail. The only safe way to expand an adult jaw is via SARPE. An oral surgeon makes conservative incisions in the fused palatal bone, and a custom expander is placed. Over several weeks, you turn a key to widen the jaw bone itself, creating new bone, followed by braces to align the teeth.

Braces vs. Aligners for Adult Crossbite

As discussed in our Master Decision Matrix, the appliance must match the severity of the defect.

Treatment Timelines & Cost Expectations

• Mild Cases: 12–18 months.
• Moderate Cases: 18–24 months (requires prolonged use of cross-elastics).
• Surgical Cases (SARPE): 24+ months, accounting for pre-surgical expansion, healing, and post-surgical detailing.

Treating a crossbite requires specialized mechanics. As detailed in our Orthodontic Cost Breakdown, severe cases involving customized expansion appliances or SARPE surgery will sit at the very highest end of the pricing spectrum. However, because skeletal crossbites cause severe functional impairment, surgical correction is often heavily subsidized by medical insurance.

Risks of an Untreated Crossbite

Unlike a simple overbite, leaving a posterior crossbite untreated in adulthood causes rapid, compounding damage:

• Asymmetric Jaw Growth: Your jaw will naturally shift to one side to find a comfortable resting place, permanently skewing your facial symmetry.
• Pathological Tooth Wear: Enamel on the misaligned teeth grinds away at abnormal angles, exposing dentin.
• TMJ Stress: The unequal bite force places massive, one-sided strain on the Temporomandibular Joint, leading to chronic headaches and joint popping.
• Gum Recession: Teeth pushed out of their natural bony housing suffer from severe gum recession and potential tooth loss.