Yesterday, we touched on early childhood caries (ECC) exacerbated by sugary and acidic beverages adults commonly offer to young children.  We’ll return to the ways ECC can be prevented tomorrow.  Today, we look at what’s normal for the primary (baby) teeth.  The AAP has produced an excellent guide about pediatric dental care — A Pediatric Guide to Children’s Oral Health* — which tells you all you really need to know about dentition in children.  For instance, did you know?:

  •  By age 3 years, there are usually 20 primary teeth.
  •  The spacing between children’s baby teeth is important because it allows enough room for the bigger, permanent teeth.
  •  Primary teeth have thinner enamel and appear whiter (translucent/almost bluish) than permanent teeth.
  •  Disease may progress more quickly in primary teeth.
  •  The biting surfaces of posterior teeth are grooved and pitted.
  •  Permanent teeth have wavy edges (mamelons) when they erupt, which smooth out with normal wear and tear.


Eruption of the first tooth usually occurs between 6-9 months, though it could happen as early as 4 months old and as late as 15 months of age.  Usually the bottom two central teeth (central incisors) are the first to erupt, followed by the upper two central and upper 2 lateral incisors.  The bottom two lateral incisors are then followed by the first molars.  The four cuspids (the pointy, “canine” teeth) come next, and then the second molars (sometimes referred to as “2-year molars”).  While this pattern is typical, the order of eruption of the primary teeth can vary. (Yesterday, I saw a baby with six teeth vying to be the first to erupt.  I’d put money on the left upper central incisor being first; following that, anything goes!)

Shedding (exfoliation) of the primary teeth usually begins between 5-7 years of age (though Arthur didn’t lose his first tooth until he was 8 years old!).  Eruption of the permanent teeth begins around the same time and often follows the same pattern the primary teeth erupted in.  The permanent teeth are usually all in by 13 or 14 years old.

The outer layer on the teeth is called the enamel — the hardest substance in the human body.  The enamel is the tooth’s defense shield, protecting the underlying structure from injury and decay. As we saw yesterday, primary teeth are most vulnerable to tooth decay and cavities (caries), mostly due to the modern diet of acidic and sugary foods and beverages.  Tomorrow, we’ll look at ways to prevent early childhood caries (ECC) and promote excellent dental health for a lifetime.


(*American Academy of Pediatrics. A Pediatric Guide to Children’s Oral Health. Elk Grove Village, IL: American Academy of Pediatrics; 2009)