The subject of this volume is intentional dental modification—changing the human appearance by removing teeth, or otherwise altering their shape, surface, or color. It has been practiced, in one form or another, on every occupied continent at some point over the past 16,000 years. The contributions in this volume encompass a diverse body of work on the subject over this timespan, from Africa, Europe, the Americas, Australia, Oceania, and Asia. As a highly visible practice, dental modification may be used to send complex messages concerning a variety of topics, including status, personal identity, and group membership. But beyond this, the difficulties in identifying purposefully modified teeth, the motivations for and biocultural consequences of the practice, and even the social context in which it still occurs today are presented. As a body of work, the aim is to capture a representative spectrum of dental modification around the world, and the variety of ways in which it can inform us about the humans occupying those regions, both past and present.