Anterior Open Bite

The classic and most recognizable effect of prolonged thumb sucking. The thumb physically holds the front teeth apart during the years when the upper and lower front teeth would normally meet, producing an opening between them when the back teeth bite down. Often the open bite is shaped like the thumb itself.

Anterior open bites from thumb sucking sometimes self-correct after the habit stops if the child is still young enough to grow into a normal bite. Persistent open bites typically require orthodontic treatment, and addressing any tongue thrust the habit produced is essential to prevent relapse. See our open bite page for more.

Flared Upper Front Teeth (Increased Overjet)

The thumb pushes the upper front teeth forward and outward over years of thumb sucking, producing visibly flared upper incisors and increased overjet (the horizontal distance between upper and lower front teeth). Children with significant overjet from thumb sucking are at meaningfully higher risk of dental trauma during sports or falls because the protruding teeth are more exposed.

Treatment combines stopping the habit with retracting the front teeth orthodontically. See our protruding teeth page for more on the trauma risk and treatment approach.

Narrow Upper Jaw & Posterior Crossbite

During thumb sucking, the cheek muscles press inward on the upper jaw while the thumb pushes outward on the front teeth. This combination narrows the upper jaw across the back, often producing a posterior crossbite where the upper back teeth bite inside the lower back teeth. Many parents focus on the open bite or overjet and miss the narrow palate that develops alongside.

Caught early, palatal expansion can widen the upper jaw and resolve the crossbite. See our narrow palate page for more.

Persistent Tongue Thrust

Thumb sucking holds the tongue in a forward, low resting position for years. After the habit stops, the tongue often retains this position and continues pushing forward against the front teeth during swallowing. This persistent tongue thrust is one of the most common reasons children develop or maintain open bites and gaps even after thumb sucking ends.

Stopping the thumb sucking alone is not enough — the resulting tongue thrust often needs separate myofunctional therapy. See our tongue thrust page for more.

For most children, thumb sucking starts as a normal self-soothing behavior in infancy and toddlerhood. It calms anxiety, helps with sleep, and provides comfort during transitions. Children who developed strong self-soothing through thumb sucking sometimes continue the habit longer because it remains genuinely effective for them. This is not a sign of anything wrong — it is simply that the strategy worked too well.

Children often regress to or intensify thumb sucking during stressful periods: starting school, a new sibling, parental divorce, a move, or family illness. The habit provides comfort during transitions. Treatment timing should consider whether a child is currently navigating significant stress, because adding pressure to stop the habit during a difficult period often produces resistance and unhappiness rather than progress.

Many children only thumb suck when falling asleep or during the night. The habit becomes part of how they self-regulate to sleep, and breaking it can disrupt sleep patterns temporarily. This is one of the most challenging patterns to address because the habit happens unconsciously during the night. Habit appliances designed to be worn during sleep are often the most effective intervention for this pattern.

Some children thumb suck out of habit during quiet activities like watching TV, reading, or sitting in the car. The thumb goes in the mouth automatically without conscious awareness. These cases often respond well to awareness-building strategies and gentle reminders before more intensive intervention is needed.

For children with anxiety or who tend to feel overwhelmed, thumb sucking can become a deeply ingrained source of emotional security. These cases benefit from a supportive, non-shaming approach that addresses the underlying need for comfort while gently moving toward stopping the habit. Pediatrician or therapist input is sometimes appropriate.

Children who used pacifiers for extended periods sometimes transition to thumb sucking when the pacifier is removed. Both habits produce similar structural effects on the dental arches because the mechanism (something held in the mouth combined with sucking pressure) is similar. The orthodontic effects and treatment approach are essentially the same for both.

When Thumb Sucking Effects Become Worth Addressing

Thumb sucking before age 4 generally does not require intervention. Most children stop on their own and any minor changes resolve as growth continues. The orthodontic conversation begins when the habit persists past age 4 to 5 and structural changes become visible. By age 6 to 7, an orthodontic evaluation can identify which children have developed open bites, overjet, narrow palate, or other effects that warrant attention.

Acting during this window matters for two reasons. First, stopping the habit before adult teeth come in often allows minor structural changes to resolve naturally as the bite settles. Second, addressing the structural effects during the active growth window gives access to interventions like palatal expansion that are not possible later. The age 7 evaluation is the right time for this conversation.

What Happens When the Habit Continues Long-Term

Children (Ages 5–9)

For children still actively thumb sucking, the priority is helping them stop the habit using positive, non-shaming approaches. We typically start with awareness-building strategies, reward systems, and professional guidance before considering habit appliances. If those approaches do not succeed and structural effects are progressing, a habit appliance can be highly effective.

Once the habit stops, minor structural changes often resolve naturally. Persistent open bite, narrow palate, or overjet from prolonged sucking can be addressed with Phase 1 orthodontic treatment during this window.

Teens (Ages 10–17)

By the teen years, thumb sucking has typically stopped but the structural effects often remain. Treatment focuses on comprehensive orthodontic correction of the open bite, overjet, narrow palate, or other legacy effects. Myofunctional therapy is often essential to address persistent tongue thrust patterns established by years of thumb sucking. Comprehensive treatment typically takes 18 to 24 months.

Some teens still have active thumb sucking, particularly during sleep. We address this with habit appliances and supportive strategies as part of comprehensive care.

Adults — Legacy Effects

Many adults present with the structural legacy of childhood thumb sucking — persistent open bites, flared front teeth, narrow palate effects, and entrenched tongue thrust patterns. Treatment is comprehensive orthodontics combined with myofunctional therapy. We do not provide adult palatal expansion, so the narrow palate component is addressed through arch development.

Adult outcomes are excellent for the dental and arch-level effects. Skeletal pattern changes from years of childhood thumb sucking are largely permanent once growth is complete, and we address what is achievable honestly during consultation.

Positive Habit Modification

The first-line approach for children still actively thumb sucking. Includes awareness-building, gentle reminders, reward systems, identifying triggers (boredom, stress, sleep), and providing alternative comfort strategies. Many children stop with positive support alone, particularly when their pediatrician and orthodontist coordinate the message. We avoid shaming or punishment-based approaches.

Habit Appliances (Tongue Cribs & Thumb Guards)

Small fixed appliances that physically prevent the thumb or tongue from making the contact that drives the habit. Highly effective for children whose habit has not responded to positive modification alone. Worn for several months until the habit pattern is broken. Most children adapt within a few weeks. Habit appliances are particularly valuable for nighttime thumb sucking that the child cannot consciously control.

Palatal Expander (Growing Patients)

For children with narrow upper jaw and posterior crossbite from prolonged thumb sucking, palatal expansion widens the upper jaw during the active growth window. Often combined with habit appliances when the thumb sucking is still active, or used during Phase 1 treatment after the habit has stopped to correct the structural effects.

View palatal expander →

Myofunctional Therapy

Essential for cases where prolonged thumb sucking has produced persistent tongue thrust. Myofunctional therapists teach exercises to retrain proper tongue posture and swallow patterns. Without addressing the tongue thrust, structural improvements often relapse over time. We coordinate with myofunctional therapists in the Frisco area as part of comprehensive care.

Traditional Braces

For correcting established structural effects in teens and adults — open bite, flared front teeth, crowding from narrow palate, and other legacy changes. Braces give us precise control and remain the most reliable option for cases requiring complex movements alongside habit-related corrections.

View traditional braces →

Clear Braces

Same effective mechanics as traditional braces with tooth-colored brackets. A great option for teens and adults treating thumb-sucking-related structural changes who want the predictability of braces with less visibility during treatment.

View clear braces →

Invisalign & Angel Aligners

Modern Invisalign and Angel Aligner protocols handle most teen and adult cases addressing legacy thumb sucking effects. Particularly effective when combined with myofunctional therapy for persistent tongue thrust. The aligners themselves provide a partial physical reminder to keep the tongue and other habits in check during the day.

View Invisalign →

Pediatrician & Therapist Coordination

For children whose thumb sucking is rooted in significant anxiety or stress, coordinating with the pediatrician and sometimes a child therapist is part of comprehensive care. Addressing the underlying emotional driver often produces better results than focusing only on the habit itself. We are happy to communicate with other providers involved in your child’s care.

Thumb sucking before age 4 is generally normal and rarely causes lasting effects. The orthodontic concern begins when the habit persists past age 4 to 5, particularly when it is frequent and intense. By age 6 to 7, structural changes are often visible if they are going to develop. The age 7 orthodontic evaluation is the right time to assess whether intervention is needed.

Sometimes. If the habit stops while the child is still young (typically before age 7) and the structural changes are mild, minor open bites and other effects can resolve naturally as growth continues. More significant changes — established open bite, narrow palate, persistent tongue thrust — typically require orthodontic treatment to correct. We can tell you what is likely to happen in your child’s specific case.

Habit appliances are small fixed devices placed behind the upper front teeth that physically interrupt the contact between the thumb and the roof of the mouth or front teeth. The thumb still fits in the mouth, but the satisfying sensation of sucking is no longer there, which interrupts the habit pattern. Most children adapt within a few weeks and the habit usually breaks within several months. We use habit appliances when supportive approaches alone have not worked.

Nighttime thumb sucking can produce the same structural effects as daytime sucking because the habit happens for hours during sleep. Frequency and duration matter more than time of day. Nighttime sucking is also often the hardest pattern to address because the child cannot consciously control it. Habit appliances designed for sleep wear are particularly effective for these cases.

Yes, the orthodontic effects are essentially the same. Both habits produce open bite, increased overjet, narrow upper jaw, and tongue thrust patterns when continued past age 4 to 5. Pacifiers are sometimes easier to discontinue than thumb sucking because the parent can remove them. The treatment approach for the structural effects is the same regardless of which habit caused them.

Most PPO dental insurance plans include orthodontic benefits that apply to treatment of thumb sucking effects, particularly for documented functional issues like open bite or crossbite. Habit appliances are typically covered as part of orthodontic care. Coverage varies by plan. We are in-network with most major PPO carriers and offer flexible financing through Cherry to make treatment accessible regardless of insurance coverage.

1,000+

Five-star reviews across 3 locations

ABO

Board-certified orthodontist

Published

AJO-DO cover clinician

Free

Consultation with full diagnostic records

5605 FM 423, Suite 600
Frisco, TX 75036

FM 423 & Lebanon Rd — next to the UPS Store

West Frisco location →

4713 Highway 121, Suite 304
The Colony, TX 75056

FM 423 & Hwy 121 — next to Ross

The Colony location →

2155 University Dr, Suite 110
Frisco, TX 75033

On 380 across from Cook Children’s Medical Center Prosper

North Frisco location →