Evidence of dental agenesis in late pleistocene Homo.

OBJECTIVE: Differential diagnosis and tabulation of cases of dental agenesis in Middle and Upper Paleolithic Western Eurasian humans to synthesize this data and to test previous hypotheses about when recent human patterns of third molar agenesis were established. MATERIALS: 139 Late Pleistocene human remains and 149 individuals from three Epi-Paleolithic/ Holocene non-agricultural comparative collections. METHODS: All remains were visually and radiographically recorded by the author. RESULTS: In addition to establishing that third molar agenesis was common during the Late Upper Paleolithic (22,500-10,000 years BP), this study suggests a pattern of increasing prevalence through time. CONCLUSIONS: An increase in the prevalence of third molar agenesis in the Late Upper Paleolithic could indicate selection for dental size reduction and orthognathy, but also bio-cultural changes from more intensive food preparation techniques. SIGNIFICANCE: Third molar agenesis, a well-known developmental defect, is often reported for recent human skeletal collections, but the prevalence of the condition for Pleistocene hominins had not been previously quantified in order to consider patterns through time. Hypotheses posited for the high prevalence of third molar agenesis, or hypodontia in general, in some recent human groups require an understanding of the prevalence of these traits in the past. LIMITATIONS: Paleolithic skeletal remains are incomplete, so these values are under-estimations. Individuals are also separated diachronically and geographically and should not be assumed to represent a single population sample. SUGGESTIONS FOR FURTHER RESEARCH: Hypotheses on some of the potential selective forces acting on dental size reduction and subsequent agenesis could be tested in recent humans.

Oral pathological conditions of an Early Epipaleolithic human from Southwest Asia: Ohalo II H2 as a probable case of intentional dental ablation.

OBJECTIVE: To describe the oral pathological conditions of Ohalo II H2, an Early Epipaleolithic human from southwest Asia. MATERIALS: The dentognathic skeleton of Ohalo II H2 and relevant comparative data from similar chronological and/or geographic contexts. METHODS: Gross and x-ray observations of oral pathological conditions and occlusal wear were made following published protocols. A differential diagnosis of antemortem tooth loss is provided. RESULTS: Ohalo 2 has two carious lesions on the right M3, pulpal exposure of left M1, and mild to moderate anterior alveolar bone loss. The right I1 was lost antemortem, and there is probably agenesis of the left M3. CONCLUSIONS: The pathological conditions noted are not exceptional for a Late Upper Paleolithic forager. However, the antemortem missing right I1 is most parsimoniously explained by intentional dental ablation. SIGNIFICANCE: Ohalo 2 could represent the oldest example of dental ablation from the Late Pleistocene circum-Mediterranean world - predating the earliest examples from both North Africa and southwest Asia by several thousand years. The similarity of the Ohalo 2 ablation pattern with later Natufians provides further evidence of potential long-term behavioral trends related to the embodiment of social identities through international body modification within the Epipaleolithic of southwest Asia. LIMITATIONS: The pre-Natufian (∼23,000-14,500 cal BP) human fossil record is relatively sparse, making comparisons with the Natufian (∼14,500-11,500 cal BP) phases of the Epipaleolithic difficult. SUGGESTIONS FOR FURTHER RESEARCH: Documentation of oral pathological conditions for other pre-Natufian fossils would provide greater resolution of the temporospatial patterning of oral health and embodied social identities during the Epipaleolithic of southwest Asia.

The oral pathological conditions of the Broken Hill (Kabwe) 1 cranium.

The Broken Hill (Kabwe) 1 cranium exhibits dental caries on ten teeth, multiple periapical lesions, periodontal disease, severe anterior dental wear, and hypercementosis, conditions all little-studied in Middle Pleistocene humans and making Broken Hill 1 of great value to discussions of the antiquity of oral pathological conditions. These individual pathological conditions, however, have never previously been described in detail; the focus has been on diagnosing an overarching syndrome connecting the temporal and oral lesions. This case study examines the individual dentoalveolar pathological conditions to provide data for cross-comparison using ordinal scores (e.g., carious lesions, interdental septum condition), descriptions (e.g., hypercementosis, periapical lesions), and continuous measurements (cemento-enamel junction to alveolar crest distances). Differential diagnoses are explored including age-related hyposalivation, dental wear, lead poisoning, and diet, and are discussed within the context of past published attempts. Studies on recent humans have demonstrated correlations between oral disease, systemic health, and diet, suggesting Broken Hill 1 likely suffered from larger systemic inflammation related to its age, health, and perhaps subsistence.

Dentoalveolar paleopathology of the early modern humans from Zhirendong, South China.

The fragmentary early Late Pleistocene, early modern human remains from Zhirendong, south China, present a suite of dentoalveolar pathologies and anomalies. The lesions include lower molar buccal alveolar resorption (Zhiren 1), massive dental caries in a mandibular molar associated with hypercementosis (Zhiren 2), and bilateral mesial premolar (P3) periapical lesions (granulomata with a probable left abscess) (Zhiren 3). The Zhiren 3 periapical lesions, given their bilaterality and the non-pathological incisor and canine alveoli, suggest dens evaginatus, although absence of the Zhiren 3 dentition prevents full evaluation of this diagnosis. These periodontal abnormalities join a number of similar lesions in Pleistocene humans, of varying severity. The carious lesion is noteworthy, given the rarity of them in the Pleistocene human fossil record. In addition, Zhiren 3 exhibits unilateral P3 rotation and bilateral I1 rotation (winging).