Teeth have a close association with longevity. Enamel is the hardest substance in the body, but it does break, wear out, and is sometimes attacked by microbes. In Westernized contexts, we are all familiar with cavities, caused by acid-emitting bacteria in the mouth. But in many natural human societies, cavities (called caries) are rare. Instead, a lifetime of eating abrasive natural foods usually causes the teeth to wear down, a process called attrition.
Dental attrition is very important in the anthropology of ancient peoples. It helps us to understand the food processing techniques — for example, the use of abrasive grinding stones to process grain in early agriculturalists. Dental wear also provides a way of understanding the ages at death of ancient skeletons. In Western societies, excessive tooth wear may be indicative of habitual behaviors such as grinding the teeth, or may result from biases in the chewing pattern to one side or part of the mouth.
Differential wear describes a dentition in which one tooth is worn significantly more than its neighbors. A normal process of tooth wear results in differential wear, as first molars erupt at age 5 and develop many years of wear before the third molars erupt in the mid- to late teens.
What to do: Examine the teeth at this station. How are they worn? Is there anything complicating their wear pattern, such as the presence of caries? Which individuals have differential wear? Which are worn the most?