Sucking is a natural reflex that relaxes and comforts babies and toddlers. Children usually cease thumb sucking when the permanent front teeth are ready to erupt. Typically, children stop between the ages of 2 and 4 years. Thumb sucking that persists beyond the eruption of the permanent teeth can cause improper growth of the mouth and misalignment of the teeth. We will discuss this with you as your child is developing.