Artificial Modifications of Human Teeth

Anatomical study of a human skull with multiple osteomas in a seventeenth-century Dutch still-life painting: bone morphology and artistic intention

Skulls were frequently depicted in seventeenth-century Dutch still-life paintings. Skulls were interpreted as symbols of vanitas-meaning the evanescence of life-but their morphological features have received little attention. This study analyzed a skull with abnormal tumors in a seventeenth-century Dutch still-life painting by a renowned artist, Edwaert Collier (ca. 1642-1708), from anatomical, forensic, and pathological perspectives. The morphology of the cranium and teeth indicated that the skull likely belonged to a middle-aged female. We carefully diagnosed the abnormal masses as multiple osteomas on the skull and left femur, based on clinical studies and paleopathological literature, which reported lesions with a similar appearance to those observed in Collier's work. Furthermore, detailed observations of the cranial sutures and epiphyses of the long bones in his paintings revealed that the artist may have selected bones with a morphology that was suitable for the subject of vanitas. Collier repeatedly depicted the skull with metopism, the rare condition of having a persistent metopic suture in adulthood. A skull with a metopic suture is called Kreuzschädel, meaning the cross skull, because it forms a cruciform by connecting with the sagittal and coronal sutures. The artist might have chosen skulls with metopic sutures, which is reminiscent of the crucifixion of Christ, as an appropriate motif for the vanitas painting. This paper argues that anatomical analysis could explain the hidden meaning of the painting and disclose the fascinating collaborations between anatomy and art in the seventeenth-century Dutch Republic.

Early evidence of extra-masticatory dental wear in a Neolithic community at Bestansur, Iraqi Kurdistan

This paper presents the first evidence of extra-masticatory dental wear from Neolithic Bestansur, Iraqi Kurdistan (7700-7200 BC). Bestansur is a rare, recently excavated burial site of this period in the Zagros region, of Iraqi Kurdistan. A total of 585 teeth from 38 individuals were analyzed for features indicative of activities including oblique wear planes, notches, grooves, and chipping. Indications of extra-masticatory wear were found in 27 of 38 individuals, and 277 of 585 teeth (47%) available for study. The most frequent features were chipping and notches suggesting activities such as processing fibers by using the teeth as a "third hand." Evidence for these wear features was present in both males, females, and in children aged five and older. These aspects of childhood life-course and dentition are rarely investigated. The presence of dental wear features in the deciduous dentition can indicate an age range at which activities began in different groups and highlights the importance of including juvenile remains in such studies. The variety of forms of dental wear may relate to the mixed diet and activities of these people. This study adds to our understanding of human behaviors and socio-cultural aspects of life during this transitional period.

Skeletal remains of a Pleistocene modern human (Homo sapiens) from Sulawesi

Major gaps remain in our knowledge of the early history of Homo sapiens in Wallacea. By 70-60 thousand years ago (ka), modern humans appear to have entered this distinct biogeographical zone between continental Asia and Australia. Despite this, there are relatively few Late Pleistocene sites attributed to our species in Wallacea. H. sapiens fossil remains are also rare. Previously, only one island in Wallacea (Alor in the southeastern part of the archipelago) had yielded skeletal evidence for pre-Holocene modern humans. Here we report on the first Pleistocene human skeletal remains from the largest Wallacean island, Sulawesi. The recovered elements consist of a nearly complete palate and frontal process of a modern human right maxilla excavated from Leang Bulu Bettue in the southwestern peninsula of the island. Dated by several different methods to between 25 and 16 ka, the maxilla belongs to an elderly individual of unknown age and sex, with small teeth (only M1 to M3 are extant) that exhibit severe occlusal wear and related dental pathologies. The dental wear pattern is unusual. This fragmentary specimen, though largely undiagnostic with regards to morphological affinity, provides the only direct insight we currently have from the fossil record into the identity of the Late Pleistocene people of Sulawesi.

Biocultural diversity in Late Pleistocene/Early Holocene Africa: Olduvai Hominid 1 (Tanzania) biological affinity and intentional body modification

OBJECTIVES

The dentition of Olduvai Hominid 1 (OH1) exhibits an anomalous pattern of dental wear that was originally attributed to either intentional cultural modification (filing) or plant processing behaviors. A differential diagnosis of the wear and assessment of the biological affinity of OH1 is presented.

MATERIALS AND METHODS

Macroscopic and microscopic observations of all labial and buccal tooth surfaces were undertaken to assess wear patterns. A multivariate analysis of mandibular morphology of OH1 compared to other Late Pleistocene, Holocene, and recent modern humans was used to ascertain biological affinity.

RESULTS

The morphological variation of the OH1 mandible is closely aligned with variation in penecontemporaneous fossils from Africa and outside that of recent humans. The concave wear facets exposing dentin on the labial surfaces of all three preserved mandibular incisors is confirmed. Substantial loss of labial/buccal surfaces was documented on the surfaces of all in situ maxillary and mandibular canines, premolars, and molars ranging from distinct facets with well-defined edges, to blunting or "polishing" around areas of maximum buccal curvature. The wear on both the anterior and postcanine teeth closely resemble that caused by adornments ("labrets") worn in lower-lip and buccal facial piercings known from bioarchaeological and ethnographic contexts. The wear pattern suggests that the OH1 wore three facial piercings-two buccal/lateral and a medial one in the lower lip.

DISCUSSION

Our findings suggest that the expression of social identities through intentional body modification is more diverse than previously documented elsewhere in Africa during the Late Pleistocene (i.e., ablation) and Early Holocene (i.e., ablation, chipping, and filing).

Dental microwear texture analysis of Homo sapiens sapiens: Foragers, farmers, and pastoralists

OBJECTIVES

The current study seeks to determine if a sample of foragers, farmers, and pastoralists are distinguishable based on their dental microwear texture signatures.

MATERIALS AND METHODS

The study included a sample of 719 individuals from 51 archeological sites (450 farmers, 192 foragers, 77 pastoralists). All were over age 12 and sexes were pooled. Using a Sensofar® white-light confocal profiler we collected dental microwear texture analysis (DMTA) data from a single first or second molar from each individual. We leveled and cleaned data clouds following standard procedures and analyzed the data with Sfrax® and Toothfrax® software. The DMTA variables were complexity and anisotropy. Statistics included ANOVA with partial eta squared and Hedges's g. We also performed a follow-up K-means cluster analysis.

RESULTS

We found significant differences between foragers and farmers and pastoralists for complexity and anisotropy, with foragers having greater complexity than either the farmers or the pastoralists. The farmers and pastoralists had greater anisotropy than the foragers. The Old World foragers had significantly higher anisotropy values than New World foragers. Old and New World farmers did not differ. Among the Old World farmers, those dating from the Neolithic through the Late Bronze Age had higher complexity values than those from the Iron Age through the medieval period. The cluster analysis discerned foragers and farmers but also indicated similarity between hard food foragers and hard food farmers.

DISCUSSION

Our findings reaffirm that DMTA is capable of distinguishing human diets. We found that foragers and farmers, in particular, differ in their microwear signatures across the globe. There are some exceptions, but nothing that would be unexpected given the range of human diets and food preparation techniques. This study indicates that in general DMTA is an efficacious means of paleodietary reconstruction in humans.

The dawn of dentistry in the late upper Paleolithic: An early case of pathological intervention at Riparo Fredian

OBJECTIVES

Early evidence for the treatment of dental pathology is found primarily among food-producing societies associated with high levels of oral pathology. However, some Late Pleistocene hunter-gatherers show extensive oral pathology, suggesting that experimentation with therapeutic dental interventions may have greater antiquity. Here, we report the second earliest probable evidence for dentistry in a Late Upper Paleolithic hunter-gatherer recovered from Riparo Fredian (Tuscany, Italy).

MATERIALS AND METHODS

The Fredian 5 human consists of an associated maxillary anterior dentition with antemortem exposure of both upper first incisor (I¹ ) pulp chambers. The pulp chambers present probable antemortem modifications that warrant in-depth analyses and direct dating. Scanning electron microscopy, microCT and residue analyses were used to investigate the purported modifications of external and internal surfaces of each I¹ .

RESULTS

The direct date places Fredian 5 between 13,000 and 12,740 calendar years ago. Both pulp chambers were circumferentially enlarged prior to the death of this individual. Occlusal dentine flaking on the margin of the cavities and striations on their internal aspects suggest anthropic manipulation. Residue analyses revealed a conglomerate of bitumen, vegetal fibers, and probable hairs adherent to the internal walls of the cavities.

DISCUSSION

The results are consistent with tool-assisted manipulation to remove necrotic or infected pulp in vivo and the subsequent use of a composite, organic filling. Fredian 5 confirms the practice of dentistry-specifically, a pathology-induced intervention-among Late Pleistocene hunter-gatherers. As such, it appears that fundamental perceptions of biomedical knowledge and practice were in place long before the socioeconomic changes associated with the transition to food production in the Neolithic.

Dental wear and oral pathology: possible evidence and consequences of habitual use of teeth in a Swedish Neolithic sample

Atypical wear and oral lesions were studied in the dental remains from the Middle Neolithic Pitted Ware Culture site Ajvide on the island of Gotland in the Baltic Sea. Teeth (n = 764) from 17 males and 11 females were examined microscopically to document unusual wear, assess wear patterns and oral lesions as evidence of habitual behavior, and determine their effect on the oral health of this population. Five atypical wear types were observed: occlusal facets, occlusal excessive load, labial vertical striae, labial horizontal striae, and interproximal striae. Three oral lesions were recorded: chipping, periapical lesions, and dental tilting. Results indicate that teeth were used in a habitual manner at Ajvide, based on the morphology and regularity of the patterns of atypical wear. Differences were observed between the sexes, indicating gender-related differences in the habitual use of teeth. Some wear categories showed a significant correlation with age, signifying increased or accumulated wear with age. Statistically significant positive correlations were found in the molars between occlusal excessive load wear and periapical lesions as well as tilting. Other apparent links were also observed between chipping and vertical striae as well as excessive load, although these were not significant. This suggests a relationship between dental wear and dental pathologies at this site, suggesting that habitual use of teeth indirectly affected the general oral health at the site. Wear patterns, furthermore, seem to mirror both frequent activities as well as single events.

Inconsistency of the maxilla and mandible in the Minatogawa Man No. 1 hominid fossil evaluated from dental occlusion

The Minatogawa man hominid fossils are human fossils from Japan and the oldest from the Late Pleistocene period. Of the Minatogawa skeletal remains, Minatogawa Man No. 1 is best preserved and is accompanied by the mandible. When the maxillary and mandibular dentitions of Minatogawa Man No. 1 were occluded, the dentitions did not align with one another. The attrition pattern of the maxillary teeth was of an inclined type, which tilted from the buccal to lingual side, whereas that of the mandibular dentition was of a horizontal type. Moreover, both left maxillary and mandibular third molars exhibited attrition on the distal portion of the occlusal surface. The occlusal surfaces did not complement each other in the range of mandibular movement without temporomandibular joint dislocation and the curve of Spee produced by the left maxillary and mandibular occlusal planes did not match. These findings suggest that the maxilla and mandible of Minatogawa Man No. 1 are, in fact, from different individuals.