What are baby teeth? |
Throughout the course of one's life each of us will have two successive sets of teeth. The first of these sets is typically referred to as the baby teeth or milk teeth. Dental professionals use the term primary, or deciduous, dentition to refer to this same set of teeth.
The baby teeth begin to erupt (come in) at age six months or so. Then typically by age 12 all of a person's baby teeth will have exfoliated (fallen out) and been sequentially replaced by the person's second set of teeth, the permanent, or succedaneous, teeth.
How many baby teeth does a child have?
As a set, the baby teeth are composed of a total of 20 individual teeth. These teeth are divided equally between the upper and lower arches (jaws).
Each arch (top and bottom) will have 4 incisors (2 central and 2 lateral incisors) located at the center front of the mouth. Two cuspids (also termed canines or eyeteeth) lying just behind the incisors, one on each side. Furthest toward the rear of the mouth will be 4 molars (first and second molars), two on each side.
When do the baby teeth come in?
Baby teeth typically begin to erupt (as left and right pairs) at about six months of age. Usually by age 2 to 2 and a half years all of a child's baby teeth will be in place. Of course the timing of the actual eruption of any one individual's teeth will vary. Some children get their teeth early, others later. It is commonplace that these variances correlate with family histories, in the sense that the timing of tooth eruption for a child is similar to that experienced by their siblings or one of their parents.
| Eruption of baby teeth. | ||
| Tooth type | Lower arch | Upper arch |
| Central incisors | 6 1/2 months | 7 1/2 months |
| Lateral incisors | 7 months | 8 months |
| First molars | 12 to 16 months | 12 to 16 months |
| Cuspids | 16 to 20 months | 16 to 20 months |
| Second molars | 20 to 30 months | 20 to 20 months |
Why do baby teeth fall out?
A child's baby teeth will fall out (exfoliate) as their permanent successors come in. This is because the presence of an erupting permanent tooth underneath a baby tooth causes its root to resorb (dissolve away).
As a permanent tooth moves through the jawbone ever closer to the surface, the root of its corresponding baby tooth becomes shorter and shorter. Finally a point is reached where the root of the baby tooth is no longer substantial enough to keep the tooth anchored and the tooth is easily dislodged.
