How many teeth does a person usually have?

The number of human teeth typically ranges between 28 and 32, including the four wisdom teeth.

Under normal physiological conditions, the number of teeth varies according to the stages of growth and development. During the primary dentition stage, children generally begin to erupt primary teeth about six months after birth, with all primary teeth fully erupted by ages 2 to 3. There are five teeth on each side of both the upper and lower jaws, making a total of 20 primary teeth. These primary teeth perform important functions such as chewing food and assisting with speech during childhood, while also reserving space for the eruption of permanent teeth and guiding their proper alignment.

As children grow older, they begin to lose their primary teeth around age 6, marking the start of the tooth replacement phase. Permanent teeth are the second set of teeth in humans. By about 12 to 13 years of age, all permanent teeth, except the third molars (wisdom teeth), have generally replaced the primary teeth. There are seven teeth on each side of both the upper and lower jaws, making a total of 28 permanent teeth. These 28 permanent teeth perform the primary chewing functions in adulthood. They vary in shape and have specific roles: incisors cut food, canines tear food, and molars mainly grind food.

The eruption of wisdom teeth varies from person to person. Some individuals begin to erupt wisdom teeth around ages 18 to 25, with one tooth on each side of the upper and lower jaws. When all wisdom teeth erupt normally, the total number of permanent teeth can reach 32. However, due to factors such as human jawbone regression and changes in masticatory organ function, wisdom teeth often become impacted, erupt in incorrect positions, or are congenitally missing. Many people may never develop all four wisdom teeth, or may have none at all.