A correlation of tooth wear and age among modern Igloolik Eskimos

Abstract

The level of molar wear can be estimated reliably by measuring the cusp height. A correlation between age and the level of molar wear, expressed by a normalizing index (TWI) of cusp height, was found to exist in a sample of modern Igloolik Northwest Territories Eskimos. Not only was it possible to derive linear regression models to test the degree of correlation in the sample of 46 female and 39 male maxillary casts of Igloolik Eskimos, but the models were capable of accurately predicting the age of natives of the neighboring Hall Beach community. Sexual dimorphism in molar wear, perhaps attributable to differential bruxism, was demonstrated for the Igloolik sample. Based on the combined estimate of slopes for each maxillary molar pair for females and males, it was discovered that the male maxillary molars are worn approximately 30% more rapidly than female maxillary molars.

Changes in the pattern of tooth wear from prehistoric to recent periods in Japan

“…Among the quantification methods of occlusal wear applicable to a cross-sectional study are qualitative ones which give a score following subjective criteria (e.g., Murphy, 1959;Molnar, 1971), and quantitative ones such as crown height (Tomenchuk and Mayhall, 1979;Kieser et al, 1985;Walker et al, 1991), ratio of area of exposed dentin to that of occlusal surface (Behrend, 1977;Walker, 1978;Richards, 1984;Richards and Miller, 1991), and ratio of worn area to that of occlusal surface (Molnar et al, 1983). Although the methods utilizing area have an advantage in accuracy, they can evaluate only a part of the entire wear process, depending on the subject to be measured.…”

First molar size and wear within and among modern hunter-gatherers and agricultural populations

“…Molnar (1971) suggested that differences in roles between the sexes conditioned the types of food consumed, with women consuming greater amounts of fibrous plants and abrasive roots they collect. Nonetheless, Tomenchuk and Mayhall (1979) reported that Canadian Igloolik Eskimo men exhibited greater wear rates in maxillary teeth than did women, likely caused by prolonged or heavier mastication. However, another study on the same population, based on the quantitative analysis of the percentage of dentin exposure , reported that the wear of anterior teeth in females highly exceeded that in males, up to the first premolar, and the differences were more pronounced in the maxillary dentition.…”

“…Diet: meat-based. Sexual division of labor: strong but not focused on subsistence (men are the only food providers; Costa, 1977;Tomenchuk and Mayhall, 1979). M a n u s c r i p t 7 Dietary differences: low (Costa, 1977).…”

“…Agta are the indigenous inhabitants of the Philippine islands and are typical representatives of the hunting-gathering lifestyle, with a diet based on hunted meat and gathered wild fruits and other plants (Estiko-Griffin and Griffin, 1981;Minter, 2010). Inuit are arctic hunters, basing their subsistence exclusively on sea mammals' meat eaten raw, A c c e p t e d M a n u s c r i p t 15 frozen, or dry (Costa, 1977;Larsen and Rainey, 1948;Tomenchuk and Mayhall, 1979).…”

“…We can therefore assume that the diet types of the Inuit, Batéké-Balali, and Navajo are more abrasive than that of the typical hunting and gathering diet of Agta. Frozen or dried meat stored underground is difficult to chew, which implies prolonged mastication that increases the masticatory loadings (Holmes and Ruff, 2011;Waugh, 1937) and results in greater enamel loss (Tomenchuk and Mayhall, 1979). Additionally, the underground storage of dried and frozen meat (Brubaker et al, 2009;El-Zaatari, 2008;Larsen and Rainey, 1948) results in the incorporation of a significant amount of sand grains and gritty contaminants to the diet, which have been shown to cause extensive dental wear (Davies and Pedersen, 1955).…”