Root grooves on two adjacent anterior teeth of Australopithecus africanus.

Tooth 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. The characteristics of these grooves suggest the predominant aetiology was erosive wear. In addition, they are extremely similar to clinical examples of dental erosion. These are the oldest hominin examples of non-carious cervical lesions and the first described in a genus other than Homo. Further, the lesions suggest that this individual regularly processed and consumed acidic food items.

Enamel erosion and mechanical tooth wear in medieval Icelanders.

OBJECTIVES: The Icelandic Sagas are an important source of information on the way of life and diet habits in Iceland and possibly other Nordic countries 1000 years ago. Archaeological human skull material worldwide has revealed extensive tooth wear, with the main cause believed to be coarse diet. From a graveyard near volcano Hekla, 66 skeletons dated from before 1104 were excavated. The purpose of this study was to determine the main causes of tooth wear in Icelanders 1000 years ago. MATERIALS AND METHODS: Forty-nine skulls were available for research. Two methods were used to evaluate tooth wear and seven for age estimation. An attempt was made to determine the main causes of tooth wear in the light of likely diet and beverage consumption according to a computer search on food and drink customs described in the Icelandic Sagas. RESULTS: Tooth wear was extensive in all groups, increasing with age. The highest score was on first molars, with no difference between sexes. It had all the similarities seen in wear from coarse diet. In some instances it had similar characteristics to those seen in erosion in modern Icelanders consuming excessive amounts of soft drinks. According to the Sagas, acidic whey was a daily drink and used for preservation of food in Iceland until recently. CONCLUSIONS: Since acidic whey has considerably high dental erosive potential, it is postulated that consumption of acidic drinks and food, in addition to a coarse and rough diet, played a significant role in the dental wear of ancient Icelanders.

Mechanical and chemical dental wear in historical population from the Syrian lower Euphrates valley.

OBJECTIVES: The aim of this study was a comprehensive macro- and microanalysis of dental wear observed in the populations inhabiting the Syrian lower Euphrates valley. We may assume that social changes have had an important impact on the dietetic and hygienic habits of the local population. MATERIALS AND METHODS: Six periods were chosen: Early Bronze (2650-2350 BC), Middle Bronze (2200-1700 BC), Neo-Assyrian (900-700 BC), late Roman (AD 200-400), Islamic (AD 600-1200), and modern Islamic (AD 1850-1950). The dental remains belong to 196 individuals, with a total of 3292 teeth. Mechanical dental wear was evaluated according to Smith's and Shykoluk & Lovell's scale. Also, SEM technique was used to select teeth. RESULTS: Individuals from both Bronze Ages were characterized by a large percentage of severe dental wear, contrary to the younger chronological periods. The rate of dental wear slowed down from the Middle Bronze Age. The frequency of deep scratches, punctures, and pits successively decreased with younger periods, while striae became more frequent. The highest number of teeth diagnosed with erosive loss was from the Neo-Assyrian period. DISCUSSION: In the Early and Middle Bronze Ages the diet was rather hard and more contaminated. The diet in the Neo-Assyrian period was rich in products lowering the pH in the oral cavity. The frequency of dental erosion in two consecutive periods--Islamic and late Roman--took place at a similar level. Thus similar alimentary habits in these periods can be suggested.

Lesiones cervicales no cariosas y su probable relación con factores oclusales: perspectiva histórico-evolutiva / Non-carious cervical lesions and its probable relationship to occlusal factors: historical and evolutionary perspective

La pérdida de sustrato dentario de origen no bacteriano ubicada en la región cervical, alrededor del límite amelo-cementario, comúnmente llamada lesión por abfracción es una de las patologías dentarias más frecuentes en la actualidad. Diseminada mundialmente, no respeta género, sociedades ni, en ocasiones, grupos etarios. Lógicamente, la mayoría de las veces, es relacionada con la parafunción; sin embargo, no ha podido establecerse hasta el momento de modo certero, ni comprobado científicamente, que ésta sea un factor determinante en su origen y desarrollo. Una perspectiva antropológica en cuanto a la evolución y modificación del sistema estomatognático podría evidenciar elementos que pueden colaborar a establecer un probable origen de este tipo de lesiones...

The cervical loss of dental substrate other than a bacterial origin located at the enamel-cementum junction commonly called abfraction is one of the most frequent pathologies nowadays. Disseminated worldwide, does not respect gender, communities or sometimes age groups. Naturally, most of the time, related to parafunction, it could not be established until now an accurate source not scientifically proven that this factor is decisive in developing such lesions. An anthropological perspective regarding the evolution and modification of the stomatognathic system could demonstrate elements that can collaborate to establish a probable origin of this lesions...

Eighteenth and nineteenth century dental restoration, treatment and consequences in a British nobleman.

This paper examines unusual eighteenth and nineteenth century dental treatment and its consequences, in a nobleman excavated from beneath St. Nicholas' Church, Sevenoaks, Kent, UK in the early 1990s. This rare archaeological case exhibits erosion of dental enamel on the labial surface of all the anterior dentition. A programme of historical research suggests that this might be attributed to the application of an acid-based dental tincture or the use of an abrasive substance to whiten the teeth. Palliative treatment for the consequence of this application was prescribed by Dr Robert Blake of Dublin. Further, it bears witness to three dental restorations, two of gold and one tin. The two gold (foil) fillings are an occlusal in the upper-right second molar and a cervical on the labial surface of the upper left canine. The tin filling is an occlusal in the upper left second molar. Excavation of the carious tissue appears to have been undertaken using a spoon shaped implement.

Human dental microwear caused by calcium oxalate phytoliths in prehistoric diet of the lower Pecos region, Texas.

Recent research demonstrates that silica phytoliths of dietary origin are associated with microwear of human teeth. Previous research has shown that severe enamel microwear and dental wear characterizes Archaic hunter-gatherers in the lower Pecos region of west Texas. Calcium oxalate crystals are especially common in Archaic coprolites. The vast majority are derived from prickly pear and agave, which were the dietary staples in west Texas for 6,000 years. The calcium oxalate phytoliths are harder than enamel. Therefore, calcium oxalate crystals are the most likely source of previously documented dental microwear and wear in the lower Pecos region.

Subvertical grooves of interproximal facets in Neandertal posterior teeth.

Subvertical grooves, located on the interproximal facets of most Neandertal posterior teeth, are less frequently noted on the teeth of other hominids, including modern humans. These grooves, 0.1-0.5 mm in width, are strictly localized within the facet area. Scanning electron microscopic (SEM) examination of grooves present on Neandertal teeth from Caverna delle Fate (Liguria, Italy) and Genay (Côte d'Or, France) demonstrated that they were produced during the life of these individuals. Characteristics of the groove surface suggest an erosion-abrasion mechanism of formation. These grooves, which developed in parts of the dentition exposed to marked stress, originated in areas characterized by changes in the orientation of enamel prism bundles (i.e., Hunter-Schreger bands). Observations carried out on modern human molars showed a subvertical disposition of these bands near interproximal ridges facilitating subvertical microfractures. Possible correlations between enamel structure, masticatory stress, and interproximal groove formation in Neandertals are discussed.

Regurgitation erosion as a possible cause of tooth wear in ancient British populations.

Clinically, in modern populations, tooth wear can be differentiated into three main types--attrition, abrasion and erosion, acting either separately or together. Anthropologists generally have not recognized erosion as a factor affecting the teeth of past populations. This study compares the patterns of wear known to be associated with erosion in present-day dental patients with those found in some British, pre-Conquest, skeletons. It is concluded that erosion may have been a major factor causing the extensive tooth wear in some 20 of 151 individuals.

Tooth wear in Australian aboriginal populations from the River Murray Valley.

The study of tooth wear among prehistoric and recent populations has frequently been concerned with the rate and pattern of wear over the dental arches. In this report we considered the question of tooth wear variation among collections of Australian Aboriginal crania recovered from several sites along the Murray River in Southeastern Australia. These crania represent the remains of relatively recent populations from about 2,000 years ago until the early 19th century. The degree of tooth wear for each dental arch was recorded by an established method of determining the ratio of exposed dentin. The pattern or distribution of wear over each arch was summarized by principal component analysis. The mean wear degree and pattern were compared among four geographical grouping of crania separated by up to 700 miles of river frontage. Our results showed, as expected, a significant difference between the well-defined population at the Lower Murray site (Swanport) and the three upriver groups. However, there were significant differences among these three collections as well. Sexual dimorphism was noted but was only significant in the Lower Murray group; the mean wear was greater and also more variable among the males. At the second of the Middle Murray sites the pattern of wear was different and the degree of wear was significantly less than in the other groups. A possible explanation for this diversity may be environmental and subsistence base differences. The evidence from the Lower Murray supports this possibility, but the differences among the other three groups are not as clearly established. However, our results do suggest that the Murray Black collection, from which these crania were obtained, may not be as homogeneous a group as previously believed.