A typical adult human has 32 teeth, including four wisdom teeth. This permanent set contains 16 teeth in the upper jaw and 16 in the lower jaw: incisors, canines, premolars, and molars.
The four wisdom teeth are the third molars, one at the back of each quadrant of the mouth. They commonly emerge between the late teens and early twenties, which explains the traditional name: they appear when a person is supposedly wiser. However, not everyone develops all four, and some remain trapped beneath the gums or are removed.
The number 32 describes the usual full permanent dentition, not every individual adult’s actual count. A person may have fewer teeth because wisdom teeth never formed, failed to erupt, or were extracted. Extra teeth, known as supernumerary teeth, are possible but uncommon.
The 20 primary, or baby, teeth are a separate earlier set. They eventually make way for permanent teeth, including the premolars and third molars that are not present in the primary dentition.