Even though baby teeth are eventually replaced with permanent teeth, it is still important to a child’s overall health. It is okay for infants to suck their thumbs, fingers, toys, or pacifiers. Sucking an object gives children a feeling of comfort. Depending on how much a child sucks their thumb, the permanent teeth that begin to come in can end up being pushed out forward, which forms an overbite.
An overbite is when the upper front teeth overlap the lower ones. This is why it is important to try and make this habit stop by the age of 6. With an overbite, children can also have problems with speech. A lisp can be formed which interferes with the correct formation of words and sounds. Thumb sucking can also lead to buck teeth, which will effect the shape of the face.
To help your children stop this habit, try to encourage them with rewards. Provide them with a toy after a certain amount of days they go without sucking their thumb. Mark progress on a calendar where the child can see the progress he/she is making. Most important, no nagging! Children get defensive if the parent is nagging to much about stopping the habit.