The “normal” adult human has 32 teeth. An adult should have 32 teeth with 8 incisors, 4 canines, 8 premolars, and 12 molars which include the four wisdom teeth. Humans develope 2 sets of teeth in their lives. the first set known as baby teeth began to come though at about age 6 months. They eventually have about 20 teeth as children before they began to lose them.
The second, permanent set of teeth consists of 32 teeth. Twenty-eight of them appear between the ages of about 6 and 12 years. Secondary teeth do not push deciduous teeth out of their sockets; instead, a group of cells (odontoclasts) forms in front of tip of second tooth and dissolves the base of first tooth. Finally, the first tooth is held in place only by tissues of gum. Deciduous molars are replaced by premolars. The third molars (the wisdom teeth) are the final teeth to erupt, usually around age 20. However, it is common for the wisdom teeth not to erupt at all; this is often the case in small jaws without room to support the extra teeth. It is possible, though rare, for a person to have fourth molars, and there have been instances where fifth molars have been present in the dentition.
Humans usually have 20 primary (deciduous or “baby”) teeth and 32 permanent (adult) teeth. Teeth are classified as incisors, canines, premolars, and molars. Incisors are primarily used for biting pieces from foods such as raw carrots or apples and peeled but uncut bananas, while molars are used primarily for grinding foods after they are already in bite size pieces inside the mouth.