A full set of baby teeth consists of 20 teeth. That includes two central incisors, two lateral incisors, two canines and two sets of molars on the top and bottom. Baby teeth follow a general eruption schedule for eruption (coming through) and for exfoliation (being lost.) The eruption schedule is a guideline, and slight deviations from the schedule are entirely normal in terms of time frame.
The first baby teeth to erupt are the lower front incisors, which will erupt around 6-10 months old. As soon as these two front teeth erupt, it is essential to start using a toothbrush and brushing them. As a rule, the lower teeth will erupt just slightly before the upper teeth. The baby teeth will erupt from front to back (more or less) between 6-10 months for the lower front teeth to 25-33 months for the upper back teeth. All baby teeth should be erupted by three years old. You might notice some spacing between baby teeth and these spaces are actually a very good thing. They allow room for the larger adult teeth to erupt when the time comes. These spaces also make it easier to clean the teeth and reduce the risk of cavities. Between 3-4 years old the last two teeth on each side will start to close together and at this point, it is important to start flossing, as any teeth with a closed contact have a higher risk for forming a cavity.
The exfoliation pattern is very similar to the eruption pattern. Around six years old, the lower two central incisors will be lost, following that the lateral incisors and the upper incisors. Around the same time as the adult incisors are erupting, the first permanent molars in the back will erupt. No baby teeth need to exfoliate for these big molars to come through so sometimes they go unnoticed. It is essential to make sure these first adult molars are adequately brushed and flossed. By around 12-14 years old, all baby teeth should be exfoliated, and all adult teeth should have erupted (excluding the 3rd molars or “wisdom” teeth that may erupt around 16-20 if they erupt at all.)