The oldest known impacted wisdom tooth belongs to a Magdalenian woman who lived in Ice Age Europe between 13,000 and 11,000 BCE. Third molars were grinding tools for raw roots, nuts and uncooked meat, and the heavy chewing load stimulated osteoblasts to build longer, bigger jaws. Agriculture about 10,000 years ago, cooking and then the Industrial Revolution softened diets, jaws grew shorter and wider while tooth size stayed the same, and impaction became ten times more common after industrialization. Genes such as PAX9 and MSX1 govern agenesis, the absence of wisdom teeth, which is almost unknown among Aboriginal Tasmanians and almost universal among indigenous people in Mexico.

Wisdom teeth usually erupt between 17 and 21, sometimes as early as 13, and Aristotle linked their arrival near age 20 to wisdom. About 12 percent of impacted wisdom teeth cause disease, including decay that spreads to the second molar, periodontitis, pericoronitis under a gum flap called the operculum, and odontogenic cysts that can quietly destroy bone. The 1970s idea that wisdom teeth push front teeth into crowding has been debunked, and the UK’s NICE opposes removing healthy impacted teeth. Data from 2024 show 53 percent of Americans have had them removed, but only 26 percent of those aged 18 to 29.

• How chewing tough food signals bone to grow, and why a soft diet left too little room
• Pericoronitis pain that can radiate to the ear and throat and cause trismus, locking the jaw
• Odontogenic cysts, found in up to 2.2 percent of impacted teeth, growing over 2 to 13 years
• Inferior alveolar nerve damage in about 1 in 300 extractions, and the risk of dry socket
• Platelet rich fibrin plugs spun from the patient’s own blood to reduce pain, swelling and dry socket