How many teeth does a human have?

Humans develop two sets of teeth during their lifetime: primary (deciduous) teeth and permanent teeth. There are a total of 20 primary teeth, medically classified as primary incisors, primary canines, and primary molars. Permanent teeth typically number 32, and are classified medically as incisors, canines, premolars, and molars. Specifically, there are usually 8 incisors, 4 canines, 8 premolars, and 12 molars.

The number of primary teeth is relatively constant, and all generally erupt normally. In contrast, the number of permanent teeth often varies. Some individuals exhibit congenital tooth absence—most commonly affecting the lateral incisors or third molars (wisdom teeth). Others may develop teeth that fail to erupt entirely or only partially erupt; such teeth are termed “impacted teeth” in medical terminology. Additionally, some individuals may develop supernumerary teeth—extra teeth beyond the normal complement—termed “supernumerary teeth” in dentistry.