It’s not uncommon for a child to suck his or her thumb, or the lip, or a finger, as a way to self-soothe or to help fall asleep. Most children outgrow thumb sucking between ages 2 and 4 years, which is the time when the first baby teeth fall out and permanent teeth appear. But it’s important to break a child of a thumb-sucking habit before the permanent teeth start to arrive in order to prevent problems with tooth alignment and development of the mouth. But any type of thumb, finger, or lip sucking is a habit that should be broken. It’s not always easy, but it can be done. Catch them being good. 

Notice when the child is not sucking a thumb and praise him or her effusively, rather than scolding when the child is sucking the thumb.Provide calmness and comfort. Many children suck a finger or thumb when they feel anxious. Try to determine any specific causes of anxiety for your child that might prompt thumb sucking, and address them.Enlist their help. Ask older children to help develop methods to break the habit. For example, older children may only suck a finger or thumb at night. Try putting a sock over the hand, or taping two fingers together with athletic tape. Enlist the dentist. Ask your child’s dentist to support and encourage the child to break a thumb or finger-sucking habit.