TOOTH ERUPTION
Children’s teeth begin forming before birth. As early as four months, the first primary (or baby) teeth to erupt through the gums are the lower central incisors, followed closely by the upper central incisors.
Although all 20 primary teeth usually appear by age three, the pace and order of their eruption may vary.
Permanent teeth begin appearing around age six, starting with the first molars and lower central incisors. At the age of eight, you can generally expect the bottom four primary teeth (lower central and lateral incisors) and the top four primary teeth (upper central and lateral incisors) to be gone and permanent teeth to have taken their place. The following permanent teeth will begin to erupt around age 9 or 10. This process continues until approximately age 21.
Adults have 28 permanent teeth, or up to 32 including the third molars (or wisdom teeth).