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The dental prosthesis
Published in Marshall Joseph Becker, Jean MacIntosh Turfa, The Etruscans and the History of Dentistry, 2017
Marshall Joseph Becker, Jean MacIntosh Turfa
Sexual dimorphism, size variation by sex, within any specific population has long been recognized as an important feature of human diversity parallel to that seen in other species. Sex variation has been recognized in Paleolithic Homo sapiens at least since the Middle Pleistocene (Arsuaga et al. 1997). Some scholars (Enachesco et al. 1962) believe that size and sex differences can be detected even in neonates. The use of odontometrics to determine sex had its beginnings in England (Goose 1963; Kieser 1990), also in America (Garn et al. 1967). Ditch and Rose (1972) expanded on the work of Goose (1963) by demonstrating that differences in human tooth size provide 93 percent accuracy in the evaluation of sex. They found incisors less diagnostic than molars, with canines showing the least dimorphism (also Kieser 1990: 67–70). Kieser (1990) indicates how chromosomal effects influence the transmission of these differences. Other scholars were less successful in recognizing human sexual dimorphism in teeth, but did have some success using discriminant function analysis with molars. Rösing et al. (1995) have perfected their original research. Improved statistical techniques have enhanced predictability and now almost all teeth can be successfully used to evaluate sex. Stermer Beyer-Olsen and Alexandersen (1995) found, for a medieval Norwegian population, that the “left maxillary first molar facio-lingual dimension, was not only the best discriminator in sex assessment but also the tooth most often available for study.” Maxillary first molars are the tooth preferred by Becker for evaluating sex, but are not always available.
Morphological variations and prevalence of aberrant traits of primary molars
Published in Annals of Human Biology, 2021
P. Sujitha, R. Bhavyaa, M. S Muthu, M. Kirthiga
Odontometrics is the measurement and study of tooth size. Crown dimensions consist of mesiodistal and buccolingual measurements. Studies on metric traits among various populations and ethnicities show that Western Eurasian populations appear to have smaller teeth (Hanihara and Ishida 2005), while the Indigenous Australian Aboriginals, Melanesians, Micronesians, Sub-Saharan Africans and Native Americans tend to have larger teeth (Hanihara and Ishida 2005). East and Southeast Asian populations were found to be intermediate in tooth size between these groups (Barberia et al. 2009). Modern humans are characterised by the extent of tooth size and pattern variations among different ethnicities (Barrett et al. 1963). It is also said that the association of teeth with respect to crown dimensions appears to be high in both the primary and permanent dentitions (Moorrees and Chadha 1962). Numerous studies (Moorrees and Chadha 1962; Moorrees and Reed 1964; Garn et al. 1966; Brown et al. 1980; Lysell and Myrberg 1982; Axelsson and Kirveskari 1983; Yuen et al. 1997; Kondo and Townsend 2004) have been conducted to determine the metric dimensions of the permanent dentition. These studies put forward the assertion that males of East Asian populations (Yuen et al. 1997; Kondo and Townsend 2004) have larger size teeth than females in all or most teeth when compared to Caucasians (Lysell and Myrberg 1982; Axelsson and Kirveskari 1983). Sexual dimorphism in tooth size is more pronounced in the permanent than in the deciduous dentition especially in populations like Great Britain (Garn et al. 1966), White Americans (Moorrees and Chadha 1962) and Indigenous Australians (Brown et al. 1980). However, studies performed in the primary dentition with regard to odontometrics are scarce and based primarily on geographic and racial variables. Upon comparison among the various geographic areas, both the mesio-distal and bucco-lingual dimensions are suggested to be larger among East Asian populations, namely the Indigenous Australians (Margetts and Brown 1978) and Chinese populations (Yuen et al. 1997). Caucasians tend to have smaller dimensions, particularly White Americans (Moorrees and Chadha 1962), people of Sweden (Lysell and Myrberg 1982), and populations of Great Britain (Garn et al. 1966).