How many teeth does a human have?

The number of human teeth may vary between different age stages and individuals, and can be divided into two stages: primary teeth and permanent teeth.

Primary Teeth Stage:

1. Primary teeth are the first set of teeth in humans. They usually begin to erupt at about 6 months after birth and are fully erupted by about 2 and a half years of age.

2. There are a total of 20 primary teeth, with 5 in each of the upper and lower jaws on both sides. These include the central incisors, lateral incisors, canines, first primary molars, and second primary molars.

Permanent Teeth Stage:

1. If no wisdom teeth erupt, the total number of permanent teeth is 28.

2. If all four wisdom teeth erupt, the total number of permanent teeth is 32.

3. However, in reality, due to various factors affecting the eruption of wisdom teeth, many people do not develop all four wisdom teeth, and some individuals may not develop any at all.

4. Permanent teeth are the second set of teeth in humans and are the final teeth used. After the primary teeth fall out, permanent teeth begin to erupt and gradually replace the primary teeth.

5. Under normal circumstances, the total number of permanent teeth varies between 28 and 32. This variation is due to individual differences in the eruption of wisdom teeth.

Note that this number may vary between individuals, depending on the absence of wisdom teeth or the presence of extra teeth.