Common habit of small children.

Sucking the thumb (or other fingers) is a common habit among younger children and it generally stops on its own when the child is about 4 years old. However, if children retain the habit until the time when permanent teeth start erupting, it may adversely affect the shape of the oral cavity and dentition (especially upper incisors) as well as causing deformation of the alveolar process resulting in bite defects. The degree of deformation depends on the frequency and duration of thumb sucking, and on the position of the thumb in the oral cavity while sucking. Each child sucks the thumb a little differently.
 

How to help your child break the habit?

How to break the habit? Pick a good time, when your child is not under stress. Do not try to make them drop thumb sucking when the child is sick, or during holidays. Explain to the child that thumb sucking may have serious consequences. Reward the child even for small progress in breaking the habit. All the family members should be happy about the fact that the child makes an effort not to suck the thumb. In fact, breaking the habit is an enormous challenge for the child – comparable to attempts to withdraw from a powerful habit made by adults.
 

Help the child by accepting what he/she does. Do not scold them. Offer assistance.
If you see that your child does not suck the thumb in a typical thumb-sucking situation – provide praise and reward.
The strategy is bound to work!