Root caries on aParanthropus robustusthird molar from Drimolen

Abstract

ObjectivesDental caries is often perceived as a modern human disease. However, their presence is documented in many early human groups, various non-human primates and, increasingly, our hominin ancestors and relatives. In this study we describe an antemortem lesion on the root of a Paranthropus robustus third molar from Drimolen, South Africa, which likely represents another example of caries in fossil hominins. Materials and MethodsThe molar, DNH 40, is dated to 2.0-1.5 Ma and displays a lesion on the mesial root surface, extending from the cementoenamel junction 3 mm down toward the apex. The position and severity of the lesion was macroscopically recorded and micro-CT scanned to determine the extent of dentine involvement. Results A differential diagnosis indicates root caries, as the lesion is indistinguishable from clinical examples.Although necrotic in appearance, external tertiary dentine is evident on a micro CT scan. Gingival recession and/or continuous eruption of the tooth as a result of extensive occlusal wear would have occurred to facilitate caries formation. Therefore, the lesion is likely linked to relative old age of this individual. DiscussionThis new example increases the total number of carious lesions described in P. robustus teeth to 12, on occlusal, interproximal and, now, root surfaces. Beyond the consumption of caries-causing food(s), caries formation would have also required the presence of requisite intra-oral cariogenic bacteria in this individual and the species. Of interest, the presence of tertiary dentine on the outward surface suggests the DNH 40 lesion may have been arrested, i.e., no longer active, perhaps relating to a change in diet or oral microbiome just prior to the individual's death.

Dental abscesses on the maxilla of a two million-year-old earlyHomospecimen

“…In this study, we recorded the presence/absence of periapical voids in South African fossil hominins, for comparison with those reported in more recent populations and other primate species. Our working hypothesis was that their presence likely resulted from crown wear, given its ubiquity in many hominin specimens, rather than caries, which are comparatively uncommon (Towle, 2019;Grine et al, 1990). We then conducted a differential diagnosis on one early specimen of Homo presenting several large voids on the anterior aspect of the maxilla to discern the etiology.…”