Why do we have crooked teeth when our ancestors didn’t? - G. Richard Scott

The Historical Perspective00:00:06

Fossil records show that ancient humans typically possessed perfectly straight teeth and functional wisdom teeth, contrasting with modern reliance on braces and surgical extractions.

The Impact of Dietary Evolution00:00:41

Early human ancestors had larger jaws and teeth to handle tough, raw foods. The advent of tools, fire for cooking, and later industrial farming and food processing reduced the need for intense chewing, which scientists believe led to a reduction in jaw size.

The Mismatch Hypothesis00:02:30

The current theory is that human jawbones have reduced in size due to softer diets, while tooth size has not decreased at the same rate, resulting in dental crowding, misalignment, and impacted wisdom teeth.

Experimental Evidence00:03:30

Studies on squirrel monkeys and hyraxes show that individuals raised on softer or cooked diets develop narrower dental arches and more crowded, displaced teeth, suggesting the problem is primarily environmental rather than purely genetic.

Conclusion and Variability00:04:23

While 30-60% of modern humans experience tooth crowding, it remains variable based on global populations and diet. Those who consume less-processed foods often show fewer dental issues.