A common habit in young children, which provides comfort, oral gratification, amusement when bored, and reassurance. Thumb-sucking tends to decrease after age 3, and most children grow out of it by age 7. In most cases, it is not harmful. However, malocclusion of the permanent teeth may develop if the habit continues past age 7. This is usually temporary; if not, an orthodontic appliance may be needed.


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