Teeth begin forming while you’re still in the womb. The emergence of primary (or baby) teeth typically starts around 3-4 months of age. The initial teeth to appear are usually the lower central incisors, followed closely by the upper central incisors. By the age of 3, most children will have all 20 primary teeth, although the exact timing and order of eruption can vary.
The transition from primary teeth to permanent teeth occurs over several years and is generally divided into two main stages. The first stage spans from ages 6 to 8, during which the incisors are replaced, and the first permanent molars emerge. The second stage begins around ages 9 to 10 and continues until approximately age 12. This phase involves the replacement of canines and primary molars with permanent teeth.