Deciduous teeth

1 minute read

Like most mammals, humans have two sets of teeth. The first set is called the deciduous dentition, but you probably know these as “baby teeth.”

The human deciduous dentition includes two incisors, one canine, and two molars in each quadrant. When people lose their deciduous molars, these are replaced by permanent premolars. The permanent molars do not have deciduous teeth in their places before them.

Deciduous teeth are abbreviated with a “d” and the tooth type and number in lowercase. For example, the deciduous lower first molar is a dm1; the upper left deciduous canine is luc.

What to do: Consider the series of models at this station. They represent the mandibular dentitions of children at different ages during their development. Can you determine the order that the permanent teeth erupt and replace the deciduous teeth? For example, are the permanent incisors the first to erupt? The permanent molars?

Part 2

There are several kinds of primate represented at this station. These primates have different adult body sizes, and grow at very different rates. Nevertheless, their teeth erupt in sequences that are very much like the human dental eruption sequence.

Yet, there are exceptions. Many primates erupt their canine teeth relatively late in their eruption sequence. In humans, the upper canine typically erupts before the second molars. In many primates, the canine is delayed in development compared to the second molars.

What to do: Examine the primate dentitions at this station. Identify the deciduous and permanent teeth that you see in each. Try to think about what age a human would likely be, with the same teeth present. Can you find aspects of tooth eruption that differ between humans and these primates?