Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology of the teeth of an animal.
Cast of a human upper jaw showing incisors, canines, premolars, and two of the three possible sets of molars.
Deciduous teeth or primary teeth, also informally known as baby teeth, tothlings, milk teeth, or temporary teeth, are the first set of teeth in the growth and development of humans and other diphyodonts, which include most mammals but not elephants, kangaroos, or manatees, which are polyphyodonts. Deciduous teeth develop during the embryonic stage of development and erupt during infancy. They are usually lost and replaced by permanent teeth, but in the absence of their permanent replacements, they can remain functional for many years into adulthood.
Bottom teeth of a seven-year-old, showing primary teeth (left), a lost primary tooth and visible socket (middle), and a fully erupted permanent tooth (right)