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How thumb-sucking can change your smile

Children often suck their thumbs or fingers for comfort.  Generally, with some gentle encouragement, children grow out of these habits before any damage is done.  However, prolonged and persistent sucking habits beyond a certain age can significantly alter the position of the teeth and jaws.

The problems associated with sucking habits can include:

  • Protruding upper front teeth: During thumb sucking, the thumb is normally placed in the roof of the mouth on the back surfaces of the incisors.  The forces from the sucking action cause tipping of the upper front teeth causing them to stick out.  If the habit is persistent, it can also result in a forward position of the upper jaw.
  • Lower front teeth tipped in towards the tongue: The thumb or digits often rest on the lower incisors during sucking which can cause them to tilt backwards.  This increases the distance between the upper and lower front teeth, emphasizing the protrusion of the upper teeth.
  • Crossbite: The tongue normally rests in the roof of the mouth.  When a thumb or finger is in the mouth, it pushes the tongue down allowing the muscles active when sucking to push the molar and premolar teeth in towards each other.  This narrows the upper jaw meaning that it no longer sits comfortably over the lower teeth, causing a shift in the bite.
  • Anterior open bite: The tilting and tipping of the upper and lower teeth often mean that they stop overlapping vertically when the back teeth are together. As a result, a gap appears between the upper and lower front teeth that is generally the same side and shape as the thumb or digit being sucked.
  • Root resorption: The extra and abnormal forces can cause root resorption, which is when the root of the tooth slowly dissolves and shortens.


Of course, the degree of change depends on several factors including how frequently and how hard they suck their thumb and to what age the habit continues.  It is widely considered that up to 2 years of age, the effects are minimal, but it is best if the habit can be stopped by 6 years at the latest.

So, what can be done to stop the habit?

1)  Consider using a dummy for younger children as it tends to be easier to phase out than a thumb sucking habit.

2)  Lots of encouragement.  Congratulate your child for not sucking their thumb or fingers and consider small rewards for milestones reached.  Reward charts are available from many retailers, for example The Early Learning Centre, that may be helpful.

3) Something as simple as a plaster on the offending digit or wearing gloves to sleep can be a reminder to keep them out of the mouth.  Some people find that the taste of bitter anti-nail biting varnishes can prevent subconscious thumb-sucking.

4) If the habit persists Orthodontic intervention could be the answer.  A Habit Breaker appliance can be fitted to prevent stop the thumb resting behind the top front teeth. This is usually left in place for 10-12 months.

Get in touch on 01923 836334 or if you would like some advice regarding thumb or finger sucking habits.

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