Hominid Fossils

The paleopathology of hominid gnathic remains has a special attraction to Ugo Ripamonti, who had the unique possibility of examining on several occasions the fossilized remains of the ape-man of South Africa, the Australopithecinae, together with fascinating specimens of the genus Homo. Our previous findings have shown that both the gracile and robust Australopithecinae had developed alveolar bone loss possibly as a result of periodontal diseases. Recently, in collaboration with the CSIR and the Transv l Museum, we re-examined a fossil specimen, Sts 24a. previously diagnosed with a form of early-onset periodontitis (Ripamonti U. Am J Phys Anthrop 1988; 76: 197-210). Using an industrial CT scanner, it was possible to generate high quality ?serial? images of the specimen, revealing fine details of the alveolar bone, dentine, enamel, and even of the pre-existing periodontal ligament space. More importantly, it was possible to determine and visualize the extent of the vertical component of alveolar bone loss, previously hidden from examination by calcite and residual cemental breccia (Ripamonti et al. S.Afr. J. Sci. 1997; 93: 177-178).

In the B&W figure of Sts 24a, the erupting maxillary M1 is shown on the right side of the photograph, capped by a thick layer of enamel. Below the enamel and the subjacent dentin, the pulp chamber and the mesio-buccal and disto-buccal root canals are clearly discernible, together with the lamina dura of the inter-radicular bone and the periodontal ligament space of the furcation. The apices of the developing mesio-buccal and disto-buccal roots of M1 can be visualized. Root morphogenesis is still occurring as judged by the evidence of an open apex (compare to the apex of the distal root of dm2). The well preserved dm2 (in the center of the image) shows wear of the occlusal enamel and a large pulp chamber. Note the vertical defect of alveolar bone loss affecting the distal root of the dm2.