scholarly journals Root grooves on two adjacent anterior teeth of Australopithecus africanus

2017 ◽  
Author(s):  
Ian Towle ◽  
Joel D. Irish ◽  
Marina Elliott ◽  
Isabelle De Groote
Keyword(s):  
South African ◽  
Root Surface ◽  
Dental Erosion ◽  
Tissue Loss ◽  
Cervical Lesions ◽  
Dental Tissue ◽  
Australopithecus Africanus ◽  
Food Items ◽  
Anterior Teeth ◽  
Fossil Hominin

AbstractTooth root grooves and other ante-mortem dental tissue loss not associated with caries found on or near the cementoenamel junction (CEJ) are commonly termed non-carious cervical lesions. Three main processes are implicated in forming these lesions: abrasion, dental erosion, and abfraction. As yet, these lesions have not been described in non-Homo hominins. In this study South African fossil hominin collections were examined for evidence of any type of non-carious cervical lesion. Only one individual shows ante-mortem root grooves consistent with non-carious cervical lesions. Two teeth, a mandibular right permanent lateral incisor (STW 270) and canine (STW 213), belonging to the same Australopithecus africanus individual, show clear ante-mortem grooves on the labial root surface. These lesions start below the CEJ, extend over a third of the way toward the apex, and taper to a point towards the lingual side. Microscopic examination revealed no clear directional striations. The shape of these grooves is extremely similar to clinical examples of dental erosion, with the lack of striations supporting this diagnosis. These are the oldest hominin examples of non-carious cervical lesions and first described in a genus other than Homo; further, the lesions suggest that this individual regularly consumed or processed acidic food items.

Metacarpals and manual phalanges

2020 ◽  
pp. 106-143
Author(s):  
Tracy L. Kivell ◽  
Kelly R. Ostrofsky ◽  
Brian G. Richmond ◽  
Michelle S.M. Drapeau
Keyword(s):  
Body Size ◽  
South African ◽  
Index Finger ◽  
External Morphology ◽  
Australopithecus Africanus ◽  
Fossil Evidence ◽  
Frequent Use ◽  
Selection For ◽  
Locomotor Behaviors ◽  
Fossil Hominin

This chapter presents description and analysis of the metacarpals and manual phalanges from Sterkfontein. Although the morphology is generally similar across the sample where there are duplicates of the same element, there are differences in size that are quite remarkable within the context of all South African hominins. Some very large specimens suggest the presence of individuals at Sterkfontein with much larger hands, and presumably larger body size, at Sterkfontein than those of A. sediba MH2, H. naledi and the Swartkrans hominins. Australopithecus africanus had human-like proportions, but this may be plesiomorphic within the hominoid clade. The potentially less mobile trapezium-Mc1 joint, absence of a fully developed palmar pulp on the distal thumb, more limited pronation of the index finger, and potentially more wedge-shaped trapezoid inferred from the preserved external morphology, is consistent with lower manipulative loading of the thumb than is typical of later Homo. As for other forelimb elements, moderately curved manual phalanges suggests a greater reliance on forelimb-dominated locomotor behaviors and perhaps selection for more frequent use of an arboreal environment in A. africanus than is found in A. afarensis. Thus, within this broader context, the Sterkfontein fossil hominin remains are not unusual. The Sterkfontein hand fossils suggest an overall manipulative and locomotor loading regime that was more similar to that of other South African australopiths and distinct from that of later Homo, but more refined functional interpretations require additional fossil evidence, particularly from associated hand skeletons

scholarly journals Developmental stress in South African hominins: Comparison of recurrent enamel hypoplasias in Australopithecus africanus and Homo naledi

2019 ◽  
Vol 115 (5/6) ◽  
Author(s):  
Mark F. Skinner
Keyword(s):  
South African ◽  
Geographical Area ◽  
Developmental Stress ◽  
Enamel Hypoplasia ◽  
Enamel Defects ◽  
Australopithecus Africanus ◽  
Anterior Teeth ◽  
Equatorial Africa ◽  
Linear Enamel Hypoplasia ◽  
Digital Microscope

Discovery of a new hominin (Homo naledi) in the same geographical area as Australopithecus africanus creates the opportunity to compare developmental dental stress in higher latitude hominins with low that in latitude apes, among whom repetitive linear enamel hypoplasia (rLEH) recurs seasonally at about 6 or 12 months. In contrast to equatorial Africa, a single rainy/dry cycle occurs annually in non-coastal southern Africa. It is predicted that LEH will recur annually but not differ in duration between ancient and more recent hominins. Data were collected from epoxy casts of anterior teeth attributed to H. naledi (18 incisors, 13 canines) and A. africanus (29 incisors, 8 canines) using a digital microscope, surface scanner and scanning electron microscope. The location, number, width, depth and distance between defects (including perikymata counts and spatial measurements) of 136 LEH events were compared among crown moieties (deciles 4–6 and 7–9), tooth types and taxa. Enamel defects are concentrated in the cervical half of anterior crowns, and in similar numbers in each taxon. Contrary to expectations, H. naledi show bimodal LEH durations reconstructed at about 2 and 8 weeks compared to just 4 weeks in A. africanus. Both taxa show bimodally recurrent episodes of LEH centring on 2 and, more commonly and severely, 6 months. A combination of two independent annual stressor types, one disease and one seasonal, could explain the observations. These estimations of duration and recurrence of developmental stress require evaluation using actual perikymata periodicity for H. naledi and more refined understanding of palaeoenvironments for both taxa. Significance: Seasonal stress is a central concern in the biological and health sciences. Because of the innate way that enamel is deposited, the timing of stress in the childhood of apes, modern humans and their fossil ancestors can be measured with a precision of about 1 week. Application of this method to South African Pliocene Australopithecus africanus and Mid-Pleistocene Homo naledi reveals that, unexpectedly, both forms show semi-annual stress – a finding that is tentatively attributed to two independent annual stressors, possibly disease and malnutrition.

scholarly journals Stable isotopes in fossil hominin tooth enamel suggest a fundamental dietary shift in the Pliocene

2010 ◽  
Vol 365 (1556) ◽  
pp. 3389-3396 ◽  
Author(s):  
Julia A. Lee-Thorp ◽  
Matt Sponheimer ◽  
Benjamin H. Passey ◽  
Darryl J. de Ruiter ◽  
Thure E. Cerling
Keyword(s):  
South African ◽  
Tooth Enamel ◽  
Dietary Shift ◽  
Australopithecus Africanus ◽  
Isotopic Evidence ◽  
High Resolution Analysis ◽  
Resolution Analysis ◽  
Dietary Ecology ◽  
Dietary Shifts ◽  
Fossil Hominin

Accumulating isotopic evidence from fossil hominin tooth enamel has provided unexpected insights into early hominin dietary ecology. Among the South African australopiths, these data demonstrate significant contributions to the diet of carbon originally fixed by C 4 photosynthesis, consisting of C 4 tropical/savannah grasses and certain sedges, and/or animals eating C 4 foods. Moreover, high-resolution analysis of tooth enamel reveals strong intra-tooth variability in many cases, suggesting seasonal-scale dietary shifts. This pattern is quite unlike that seen in any great apes, even ‘savannah’ chimpanzees. The overall proportions of C 4 input persisted for well over a million years, even while environments shifted from relatively closed ( ca 3 Ma) to open conditions after ca 1.8 Ma. Data from East Africa suggest a more extreme scenario, where results for Paranthropus boisei indicate a diet dominated (approx. 80%) by C 4 plants, in spite of indications from their powerful ‘nutcracker’ morphology for diets of hard objects. We argue that such evidence for engagement with C 4 food resources may mark a fundamental transition in the evolution of hominin lineages, and that the pattern had antecedents prior to the emergence of Australopithecus africanus . Since new isotopic evidence from Aramis suggests that it was not present in Ardipithecus ramidus at 4.4 Ma, we suggest that the origins lie in the period between 3 and 4 Myr ago.

scholarly journals Tertiary dentine frequencies in extant great apes and fossil hominins

2018 ◽  
Author(s):  
Ian Towle
Keyword(s):  
South African ◽  
Great Apes ◽  
Gorilla Gorilla ◽  
Great Ape ◽  
Loss Of Function ◽  
Gorilla Gorilla Gorilla ◽  
Australopithecus Africanus ◽  
Occlusal Wear ◽  
Fossil Hominins ◽  
Fossil Hominin

Tertiary dentine forms when an odontoblast is directly affected by stimuli, commonly through occlusal wear. In this study the presence of tertiary dentine is recorded in three South African fossil hominin species (Australopithecus africanus, Homo naledi and Paranthropus robustus), and two extant great ape species (Gorilla gorilla gorilla and Pan troglodytes). Frequencies of tertiary dentine were calculated for each species based on macroscopic observations of teeth with dentine exposed through occlusal wear. Overall, the three hominin species have similar tertiary dentine frequencies ranging from 12% to 16.13%. In contrast, over 90% of gorilla teeth with dentine visible show tertiary dentine. Chimpanzees fall between these extremes with 47.21% of teeth affected. Species variances are not related to differences in occlusal wear. Instead, some species appear predisposed to produce tertiary dentine earlier and/or faster than other species. Therefore, tertiary dentine formation has the potential to provide useful information on fossil specimens. For example, the uniformly low rate of tertiary dentine formation in hominins may be due to thick enamel having a similar role in preventing loss of function of teeth, i.e., extending the life of a tooth. In contrast tertiary dentine is clearly an important mechanism for normal dental function in gorillas, and may have evolved to maintain sheering surfaces for masticating tough vegetation.

scholarly journals Tertiary dentine frequencies in extant great apes and fossil hominins

2018 ◽  
Author(s):  
Ian Towle
Keyword(s):  
South African ◽  
Great Apes ◽  
Gorilla Gorilla ◽  
Great Ape ◽  
Loss Of Function ◽  
Gorilla Gorilla Gorilla ◽  
Australopithecus Africanus ◽  
Occlusal Wear ◽  
Fossil Hominins ◽  
Fossil Hominin

Tertiary dentine forms when an odontoblast is directly affected by stimuli, commonly through occlusal wear. In this study the presence of tertiary dentine is recorded in three South African fossil hominin species (Australopithecus africanus, Homo naledi and Paranthropus robustus), and two extant great ape species (Gorilla gorilla gorilla and Pan troglodytes). Frequencies of tertiary dentine were calculated for each species based on macroscopic observations of teeth with dentine exposed through occlusal wear. Overall, the three hominin species have similar tertiary dentine frequencies ranging from 12% to 16.13%. In contrast, over 90% of gorilla teeth with dentine visible show tertiary dentine. Chimpanzees fall between these extremes with 47.21% of teeth affected. Species variances are not related to differences in occlusal wear. Instead, some species appear predisposed to produce tertiary dentine earlier and/or faster than other species. Therefore, tertiary dentine formation has the potential to provide useful information on fossil specimens. For example, the uniformly low rate of tertiary dentine formation in hominins may be due to thick enamel having a similar role in preventing loss of function of teeth, i.e., extending the life of a tooth. In contrast tertiary dentine is clearly an important mechanism for normal dental function in gorillas, and may have evolved to maintain sheering surfaces for masticating tough vegetation.

scholarly journals Dental aspects of purging bulimia

2020 ◽  
Vol 77 (3) ◽  
pp. 300-307
Author(s):  
Jovana Manevski ◽  
Ivana Stojsin ◽  
Karolina Vukoje ◽  
Ognjenka Jankovic
Keyword(s):  
Clinical Examination ◽  
Erosive Wear ◽  
Tooth Wear ◽  
Dental Erosion ◽  
Dental Tissue ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Dmft Index ◽  
Carious Process

vomiting, which in long term can result in irreversible loss of dental tissue, most commonly manifested as dental erosion. Frequent purging, xerostomia, lack of oral hygiene and acidic environment are also suitable for caries development. The aim of the research was to determine the presence, localization and degree of dental erosion using Basic Erosive Wear Examination (BEWE) index system, as well as to determine the Decayed, Missing and Filled Teeth (DMFT) index in purging bulimic patients. Methods. The study involved 30 purging bulimic patients and 30 healthy subjects. Used methods were survey (questionnaire) and clinical examination. The clinical examination included intraoral inspection and assessment of dental status using BEWE and DMFT index. Results. On the bases of conducted research, it has been found that dental erosion are significantly more often present in purging bulimics compared to the controls (?2 = 5.963, p < 0.05), that eroded lesions are more severe in the bulimic group (t = 3.925, p < 0.05) and predominantly located on oral surfaces of the teeth (?2 = 10.561, p < 0.05). DMFT index values showed no significant difference between bulimic patients and controls (t = 0.741, p = 0.461). Conclusion. Dental erosion are often encountered in patients suffering purging bulimia, especially on oral surfaces of anterior teeth that come into direct contact with gastric acid, so many bulimics exhibit high values of erosive tooth wear on mentioned surfaces. DMFT index score did not show significant differences compared to healthy participants, but due to complexity of carious process further investigation is necessary.

scholarly journals Dental caries in human evolution: frequency of carious lesions in South African fossil hominins

2019 ◽  
Author(s):  
Ian Towle ◽  
Joel D. Irish ◽  
Isabelle De Groote ◽  
Christianne Fernée
Keyword(s):  
South African ◽  
Human Evolution ◽  
Deciduous Teeth ◽  
Posterior Teeth ◽  
Australopithecus Africanus ◽  
Early Homo ◽  
Carious Lesions ◽  
Fossil Hominins ◽  
Specialized Diet ◽  
Fossil Hominin

AbstractCaries frequencies in South African fossil hominins were observed and compared with other hominin samples. Species studied includeParanthropus robustus,Homo naledi,Australopithecus africanus,early HomoandA. sediba. Teeth were viewed macroscopically with Micro-CT scans used to confirm lesions. Position and severity of each lesion were also noted and described. For all South African fossil hominin specimens studied, 16 have carious lesions, six of which are described for the first time in this study. These are from a minimum of six individuals, and include fourP. robustus,oneH. naledi,and oneearly Homoindividual. No carious lesions were found on deciduous teeth, or any teeth assigned toA. africanus. Most are located interproximal, and only posterior teeth are affected. Caries frequency typically ranges between 1-5% of teeth in non-agricultural human samples, and this pattern seemingly holds true for at least the past two million years in the hominin lineage. Non-agricultural populations significantly above or below this threshold generally have a specialized diet, supporting other dietary evidence thatA. africanuslikely consumed large amounts of tough, non-cariogenic vegetation. Given the common occurrence of caries in the other hominin species, cariogenic bacteria and foods were evidently common in their collective oral environment. Along with recent research highlighting additional examples of caries inH. neanderthalensis, earlyHomoand PleistoceneH. sapiens, caries is clearly an ancient disease that was much more common than once maintained throughout the course of human evolution.

scholarly journals Calcium isotopic patterns in enamel reflect different nursing behaviors among South African early hominins

2019 ◽  
Vol 5 (8) ◽  
pp. eaax3250 ◽  
Author(s):  
Théo Tacail ◽  
Jeremy E. Martin ◽  
Florent Arnaud-Godet ◽  
J. Francis Thackeray ◽  
Thure E. Cerling ◽  
...  
Keyword(s):  
Breast Milk ◽  
South African ◽  
Early Life ◽  
Tooth Enamel ◽  
Biological Evolution ◽  
Milk Consumption ◽  
Interbirth Interval ◽  
Australopithecus Africanus ◽  
The Social ◽  
Life Behavior

Nursing is pivotal in the social and biological evolution of hominins, but to date, early-life behavior among hominin lineages is a matter of debate. The calcium isotopic compositions (δ44/42Ca) of tooth enamel can provide dietary information on this period. Here, we measure the δ44/42Ca values in spatially located microsized regions in tooth enamel of 37 South African hominins to reconstruct early-life dietary-specific variability in Australopithecus africanus, Paranthropus robustus, and early Homo. Very low δ44/42Ca values (<−1.4‰), indicative of milk consumption, are measured in early Homo but not in A. africanus and P. robustus. In these latter taxa, transitional or adult nonmilk foods must have been provided in substantial quantities relative to breast milk rapidly after birth. The results suggest that early Homo have continued a predominantly breast milk–based nursing period for longer than A. africanus and P. robustus and have consequently more prolonged interbirth interval.

scholarly journals Perimolysis: case report

2015 ◽  
Vol 63 (2) ◽  
pp. 213-218
Author(s):  
Carolina Pratti DANIEL ◽  
Hérica Adad RICCI ◽  
Eloísa Marcantonio BOECK ◽  
Flavia Magnani BEVILACQUA ◽  
Jaqueline Braga Barbosa CERQUEIRA-LEITE
Keyword(s):  
Prescription Drugs ◽  
Resin Composite ◽  
Glass Ionomer Cement ◽  
Dental Erosion ◽  
Alcoholic Beverages ◽  
Dental Tissue ◽  
Restorative Treatment ◽  
Tooth Surfaces ◽  
Excessive Consumption ◽  
Ionomer Cement

Perimolysis is a form of dental erosion, characterized by dental tissue demineralization without bacterial involvement. It can be of intrinsic or extrinsic origin. Extrinsic origin is considered when it is caused by excessive consumption of acid drinks and foods such as soft drinks, alcoholic beverages, acid fruit and prescription drugs for daily use. When caused by gastrointestinal disorders, such as those resulting from bulimia, anorexia nervosa and gastroesophageal reflux, it is considered of intrinsic origin. The acid action can cause erosion on palatal/lingual incisor surfaces, and occlusal and palatal/lingual posterior tooth surfaces causing pain (dental hyperesthesia). Treatment is often multidisciplinary, and the causes should be identified, eliminated or controlled. In dentistry, the approach must include preventive measures to reduce future risks, and restorative intervention using materials such as glass ionomer cement, resin composite, or endodontic and prosthetic rehabilitation in more complex cases. The aim of this study was to describe the restorative treatment in the case of a patient with this condition.

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