Dental anthropology in the AJPA: Its roots and heights

Abstract

K E Y W O R D S : dental development, dental morphology, dentition, teethThe roots of dental anthropology in the American Journal of Physical Anthropology (AJPA) go deep. Ale s Hrdlička published his classic comparative study "Shovel-Shaped Teeth" in the AJPA in 1920, just two years after founding the journal.Hrdlička's study on shovel-shaped teeth exemplified his overall vision of physical anthropology, as articulated in the AJPA's inaugural issue. Here, in a 23-page essay, he defined the field of physical anthropology and spelled out its "scope and aims" (Hrdlička, 1918). The field as a whole, he stated, could be defined ". . .in the briefest form as the study of man's variation" (italics his). In multiple places throughout his essay, Hrdlička emphasized that the primary aim of physical anthropology is to understand the "complete" "range of variation" of human anatomy and physiology.Hrdlička was unfortunately a product of his times in thinking about human variation in terms of races and in arranging them along a gradient from primitive to advanced. However, his more fundamental point clearly still stands: physical anthropology greatly enhances our understanding of human biology though its broad perspective on human variation. Hrdlička further explained that to understand the origins of modern human variation, physical anthropologists must trace its evolutionary history. Thus, he explained, a major aim of the field is to uncover that history by studying the living primates, filling in the paleontological record, and analyzing human skeletal remains from the recent past. "Shovel-Shaped Teeth" is a prime example of how Hrdlička employed this broad, comparative approach across space, time, and species, to understand human biological variation. In this paper, Hrdlička documented human variation in the shovel-shaped trait in human skeletal collections (700 teeth), living children of diverse ancestry (2700 of them), non-human primates, and non-primate mammals. This comprehensive comparison allowed Hrdlička to discover that both East Asians and Native Americans shared high frequencies of incisor shoveling, a finding critical to his Asian-origin hypothesis for the peopling of the Americas. From his study of the incisors of non-human primates and other mammals, he gleaned insight into evolution and function. He concluded that "rimmed and hollowed incisors" (Figure 1) had evolved independently in different lineages, likely as a way to strengthen the tooth.Some of Hrdlička conclusions in this paper did not stand the test of time-for example, his idea that incisor shoveling is more prevalent in modern human populations that were late to adopt "advanced" technology. Nevertheless, this landmark paper serves to illustrate how the approach of physical anthropology Hrdlička outlined in 1918 can be used to gain insight into, and formulate hypotheses about, human biology. It also serves to illustrate how the study of teeth, specifically, can be approached to gain such insight. Finally, it helped to shape the form of modern dental ...

Evaluating the patterning cascade model of tooth morphogenesis in the human lower mixed and permanent dentition

“…Similar to previous studies, findings consistent with PCM expectations involve cusp 6 [127, 133]. Human upper molars have received more attention in PCM studies, with some outlining cusp patterns consistent with the PCM [117, 128] and others only identifying partial agreement with the model [133–135]. The inability of the PCM to consistently account for postcanine cusp development, size, and arrangement potentially indicates that this model alone may not be sufficient to explain the morphological diversity characterizing the human dentition.…”

Ancestry estimation in forensic anthropology: A review

“…In 1965, Dahlberg manufactured reference plaques to standardize the scoring systems for shovel shaped incisors, Carabelli's cusp, the hypocone, and the protostylid (Scott & Turner, ). Concurrently, there was a significant increase in dental morphological studies in the American Journal of Physical Anthropology (Guatelli‐Steinberg, ).…”

Current Theoretical and Methodological Approaches of Dental Anthropology to the Study of Tooth Morphology

“…Na rozdíl od tvrdých tkání kostí, které po celý život podléhají remodelaci, se tvrdé tkáně zubů (resp. sklovina) per se nemění, a mohou tak zachovat záznam o průběhu ontogeneze a případně také o zdravotním stavu jedince [7].…”

“…There are landmarks (red dots No. [1][2][3][4][5][6][7][8] and semi-landmarks (yellow dots) on the occlusal area and the primary cusps are labeled (pr -protocone, pa -paracone, me -metacone, hy -hypocone). Mesial is up.…”