ABSTRACT Thumb sucking is a non-nutritive habit which provides deleterious changes to the oral environment. The habit may be normal from 2-3.8 years of age, after that if the habit may continue this will result in malocclusion. The frequency and intensity of the thumb sucking habit will result in worse malocclusion. Both the child and the parents need counselling about the habit and result of malocclusion. The child may need remainder therapy or adjuvant therapy to withdraw the habit.