Thumb sucking is a natural reflex that babies and young children will do. They will begin to suck their thumb/fingers or dummy whilst in the womb. It provides great comfort to the baby, relaxing them and providing self soothing for young infants. However, if thumb sucking continues beyond certain milestones it can affect the development of the mouth, jaw bone and teeth.

If parents know how thumb sucking can affect the development of their child’s teeth they can help them in a gentle way.

1. Understanding the reflex

Understanding why children thumb suck will help parents stay calm.

  • Survival instinct – thumb sucking is a survival instinct and helps the new-born baby feed effectively from a bottle or breast.

  • Self soothing – thumb sucking releases relaxing chemicals in the brain of a young child. This helps them feel relaxed when they are tired, stressed, bored or separated.

  • Non nutritive sucking – non nutritive sucking is any sucking behavior that does not provide nutrition. This includes thumb sucking, finger sucking, toy sucking and dummy sucking.

2. When should thumb sucking stop?

Most children will stop non nutritive sucking naturally as they develop new ways to cope with their emotions, become more socially aware and learn how to communicate.

  • 0-2 years old – thumb sucking will not cause any issues. Parents do not need to do anything.

  • 2-4 years old – children will begin to reduce thumb sucking.

  • 4-6 years old – it is highly recommended by pediatric dentists to stop thumb sucking completely before the permanent front incisors start to come through around age 5/6.

3. Effects on teeth alignment and jaw development

Constant pressure on the developing bones and teeth will cause predictable changes to the mouth. The more forceful the thumb sucking the more severe the changes.

  • Anterior open bite – constant pressure from the thumb will cause the upper and lower front teeth not to meet.

  • Protrusion – the thumb will act as a lever whilst at rest causing the upper front incisors to protrude forwards towards the upper lip.

  • Lingual tipping – the base of the thumb will cause the lower front teeth to tip inwards towards the tongue.

  • Narrowed palate – negative suction pressure will cause the cheeks to pull in causing the hard palate to narrow. This will cause the upper jaw to become narrow and V shaped.

  • Posterior cross-bite – a narrow upper jaw will not fit together with the lower jaw causing the back teeth to overlap incorrectly.

4. Passive vs Active thumb suckers

Not all thumb sucking applies the same pressure. Dentists will look at how the child is sucking to determine how likely they are to have malocclusion.

Passive thumb suckers

– children who simply place their thumb in their mouth without sucking or applying any upward pressure rarely cause severe dental issues.

Active thumb suckers

– children who suck aggressively with loud suction and facial muscle movement will apply intense pressure. This will cause the teeth to move quickly and cause deformation to the soft jaw bone.

Look for signs

– parents can easily tell if their child is an active thumb sucker by looking for calluses, dry skin or redness on the main thumb.

5. Speech issues

Changes to the teeth alignment and palate will cause speech issues.

  • Lisping – anterior open bite will cause the tongue to protrude between the front teeth. This will cause distortion to the ‘s’ and ‘z’ sounds.

  • Difficulty pronouncing consonants – a narrow upper jaw will cause difficulties placing the tongue correctly on the roof of the mouth. This will cause difficulty in pronouncing the letters t, d, l and n.

  • Tongue thrusting – children with open bites often develop a tongue thrusting habit where they push their tongue forwards against their front teeth during swallowing.

6. Social and emotional aspects

Thumb sucking can affect children’s social interactions, self confidence and relationships with peers as they get older.

  • Peer pressure – children who thumb suck in kindergarten/elementary school will often be teased.

  • Emotional issues – older children who thumb suck may use it as a coping mechanism for their unaddressed anxiety and high stress.

  • Increased anxiety – being harsh and embarrassing will increase their anxiety. This will often cause them to thumb suck more aggressively in private.

7. Dummies vs thumb sucking

Many parents will wonder if encouraging their child to use a dummy is safer for their teeth.

  • Easier to stop – parents can easily throw away or hide the dummy. However children will always have access to their fingers.

  • Same issues – thumb sucking and dummy sucking will cause the same issues to the teeth if continued past 4 years old.

  • Orthodontic dummies – orthodontic dummies have flat nipples to reduce pressure on the developing front teeth. However they can still cause issues if continued.

8. Positive and gentle ways to help your child stop

Patience, positive reinforcement and encouragement will help your child stop their thumb sucking habit.

  • Positive reinforcement – reward your child with praise, star charts or small rewards for each day/night they do not thumb suck.

  • Identify triggers – notice when your child is thumb sucking, for example when watching television or in the car. Provide them with an alternative comfort item such as their favorite cuddly.

  • Gentle physical reminder – place a soft sock, cotton mitten or soft bandage over their hand at night to stop them from thumb sucking in their sleep.

  • Bitter taste – apply a safe bitter nail varnish or thumb guard to their thumb. This will remind them gently not to put it in their mouth.

  • Educate them – explain to them in simple terms how their teeth grow. This will give them a sense of empowerment to stop their thumb sucking.

9. Dental and orthodontic solutions

If gentle methods at home do not work and your child is 5/6 years old with an active habit then pediatric dentists can provide specialist appliances.

Palatal crib

– a small, comfortable metal wire appliance is glued to the back of the upper front teeth. This will stop the thumb from touching the palate and instantly stop the enjoyable suction feeling.

Hay-rake

– similar to palatal cribs. Small blunt wire prongs are attached to stop the child from putting their thumb in their mouth.

Palatal ex pander

– if the thumb sucking has caused the upper jaw to become very narrow then an orthodontist will use a palatal ex pander to widen the upper jaw bone before their permanent teeth come through.

10. Can teeth correct themselves?

Many parents worry that thumb sucking will cause permanent damage. However the body has amazing natural correcting abilities if stopped early.

  • Corrects itself before 4 years old – if the child stops thumb sucking before their permanent teeth come through then their primary teeth will often move back into the correct position naturally due to the pressure from their lips and tongue.

  • Permanent damage after 6 years old – if thumb sucking continues past their permanent incisors coming through then changes will occur that will need orthodontic treatment such as braces or clear aligners.

  • Visit a pediatric dentist – pediatric dentists recommend a full orthodontic check up by age 7.

Top tips

  • Keep track of how often, how long and how forceful your child is thumb sucking as a toddler.

  • Stay calm during infancy as non nutritive sucking provides a great self soothing technique.

  • Try to gently stop your child from thumb sucking completely or dummy sucking between 3-4 years old.

  • Reward and praise them for using alternative comfort items.

  • Identify what is causing them anxiety, for example tiredness, boredom or stress. Provide them with support.

  • Use gentle physical reminders such as soft cotton mittens or thumb guards at night.

  • Do not be harsh, embarrassing or shameful as this will increase their stress.

  • Visit a pediatric dentist if they are still actively thumb sucking past their 5th birthday.

FAQs

Can thumb sucking cause permanent damage to my child’s jaw?

Yes, aggressive thumb sucking can cause changes to the soft jaw bone. This can cause the hard palate to narrow and change the way the upper and lower jaw meet. However if addressed early by a pediatric dentist or orthodontist no permanent changes will occur.

Is using a dummy better for their teeth?

Both thumb sucking and dummy sucking can cause similar issues to the teeth if continued past 4 years old. However dummy sucking is generally easier to control. Parents can simply throw the dummy away.

How long will it take for their teeth to correct themselves?

If the child stops thumb sucking before their permanent front teeth come through then their primary teeth often move back into the correct position naturally within 6-12 months due to the pressure from their tongue and lips.

What if they only thumb suck at night?

Thumb sucking at night is a reflex. Place gentle physical barriers such as soft cotton mittens, specialized thumb guards or long sleeve pajamas with their hands covered to gently remind them.

Thumb sucking is a natural reflex for children. It will not cause any lasting issues in the early stages. However if it continues past 4/5 years old it can cause the developing teeth to move, the upper jaw to narrow and cause speech issues. Using positive reinforcement techniques at home, keeping track of how forceful they are thumb sucking and working with your pediatric dentist can help your child stop thumb sucking and leave them with a healthy and beautiful smile.