TY - JOUR
T1 - A histological reconstruction of dental development in the common chimpanzee, Pan troglodytes
AU - Reid, Donald J.
AU - Schwartz, Gary T.
AU - Dean, Christopher
AU - Chandrasekera, Malkanthi S.
N1 - Funding Information:
We are grateful to Fernando Ramirez Rozzi and Yves Coppens for the invitation to participate in the ‘‘Enamel Structure & Development’’ workshop and to the Singer-Polignac Foundation, the Hugo Foundation (College de France) and CNRS for their sponsorship. The research reported here was generously supported by grants to MCD from The Royal Society and the Leverhulme Trust. We also thank Kevin Kuykendall, Wendy Dirks, Fernando Ramirez Rozzi and David Beynon for their comments, advice, help and encouragement through various phases of this project and Rob Foley for providing some of the chimpanzee material. We are particularly grateful to the curators of the collections at the Royal College of Surgeons of England for permission to use material in their care. Special thanks go to Barry Berkovitz, Caroline Grigson and Barry Davis for their help.
PY - 1998/10
Y1 - 1998/10
N2 - Much is known about the dental development of Pan compared with that for other extant great apes. The majority of information available has concentrated either on the emergence times of teeth or on the sequence of mineralization stages of the teeth as revealed from radiographs. However, the problems of defining stages of tooth formation sufficiently accurately on radiographs are only now becoming recognized. All of the data available to date suggest the presence of a more variable picture for the timing of mineralization stages in chimpanzees than for the timing of tooth emergence. In particular, arguments persist in the literature over the time of initial mineralization and the time it takes to form each anterior tooth crown in chimpanzees. Therefore we attempt to provide a more precise chronological time scale for dental development in our closest living relative. Furthermore, we examine the sequence of molar cusp formation relative to enamel formation times related specifically to those cusps and to try to tie these data in with information from functional studies of molar crowns. Histological sections of 14 maxillary and 28 mandibular teeth from four chimpanzee (Pan troglodytes) individuals and three molar teeth from three chimpanzees of unknown origin were prepared in accordance with a well-established protocol. By combining data on short-period and long-period incremental lines (including daily secretion rates, periodicity, prism lengths and enamel thickness) in both enamel and dentine, we reconstruct times for the onset and duration of crown formation as well as construct a schedule for the pattern and timing of dental development in this one hominoid species. Interestingly, our histologically-derived data confirms that the data from radiographic studies underestimate crown formation times by the following amounts for each tooth type: I1 2·5 years, I2 3·1 years, C 1·6 years, P3 1·9 years, P4 0·1 years, M1 0·8 years, M2 1·1 years and M3 0·3 years. When combined with data on gingival emergence, it seems that chimpanzee teeth have a greatly reduced time for root growth before emergence occurs and that the major differences between Homo sapiens and Pan lie in the first part of the root formation rather than in the total period of crown formation. Maxillary and mandibular molar functional cusps take longer to complete enamel formation to the cervix than any other cusp in that same tooth, which makes sense as these cusps are thick enamelled. These results suggest that new links can be made between developmental aspects, occlusal morphology and tooth function.
AB - Much is known about the dental development of Pan compared with that for other extant great apes. The majority of information available has concentrated either on the emergence times of teeth or on the sequence of mineralization stages of the teeth as revealed from radiographs. However, the problems of defining stages of tooth formation sufficiently accurately on radiographs are only now becoming recognized. All of the data available to date suggest the presence of a more variable picture for the timing of mineralization stages in chimpanzees than for the timing of tooth emergence. In particular, arguments persist in the literature over the time of initial mineralization and the time it takes to form each anterior tooth crown in chimpanzees. Therefore we attempt to provide a more precise chronological time scale for dental development in our closest living relative. Furthermore, we examine the sequence of molar cusp formation relative to enamel formation times related specifically to those cusps and to try to tie these data in with information from functional studies of molar crowns. Histological sections of 14 maxillary and 28 mandibular teeth from four chimpanzee (Pan troglodytes) individuals and three molar teeth from three chimpanzees of unknown origin were prepared in accordance with a well-established protocol. By combining data on short-period and long-period incremental lines (including daily secretion rates, periodicity, prism lengths and enamel thickness) in both enamel and dentine, we reconstruct times for the onset and duration of crown formation as well as construct a schedule for the pattern and timing of dental development in this one hominoid species. Interestingly, our histologically-derived data confirms that the data from radiographic studies underestimate crown formation times by the following amounts for each tooth type: I1 2·5 years, I2 3·1 years, C 1·6 years, P3 1·9 years, P4 0·1 years, M1 0·8 years, M2 1·1 years and M3 0·3 years. When combined with data on gingival emergence, it seems that chimpanzee teeth have a greatly reduced time for root growth before emergence occurs and that the major differences between Homo sapiens and Pan lie in the first part of the root formation rather than in the total period of crown formation. Maxillary and mandibular molar functional cusps take longer to complete enamel formation to the cervix than any other cusp in that same tooth, which makes sense as these cusps are thick enamelled. These results suggest that new links can be made between developmental aspects, occlusal morphology and tooth function.
KW - Crown formation
KW - Cusp formation
KW - Dental chronology
KW - Dentine
KW - Enamel
KW - Growth
KW - Incremental markings
KW - Root formation
KW - Teeth
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U2 - 10.1006/jhev.1998.0248
DO - 10.1006/jhev.1998.0248
M3 - Article
C2 - 9774504
AN - SCOPUS:0032194255
SN - 0047-2484
VL - 35
SP - 427
EP - 448
JO - Journal of human evolution
JF - Journal of human evolution
IS - 4-5
ER -