20 teeth should appear - 10 in the top jaw and 10 in the bottom jaw.
Baby teeth are very important.
When teeth first come in they are not fully hardened and may decay easily. Some baby teeth are not replaced by permanent teeth until age 12 or 13. Healthy baby teeth will help your toddler look good, eat well and learn how to speak clearly. The baby teeth also guide the permanent teeth into their correct position. Diet and tooth decay Tooth decay is caused by bacteria on the teeth.