Some parents believe that the thumb sucking has no negative effects as long as the permanent teeth have not yet erupt, but the location of the teeth and facial appearance of the child are largely determined between the ages of four and fourteen. Thumb sucking or using pacifier affects the final position of the teeth. Pressure on the upper jaw and upper teeth may push them forward and change the formation of bone growth in the upper jaw, which may cause teeth irregularities.
There are multiple treatment methods. Consult your dentist to get rid of this habit.