Longitudinal analysis of deciduous tooth emergence: III. Sexual dimorphism in Bangladeshi, Guatemalan, Japanese, and Javanese children
ABSTRACT Previous studies, mostly in European populations, found sex differences in the pattern of deciduous tooth emergence. Most studies find that the anterior dentition in males is precocial relative to the female dentition, and the pattern reverses so that females lead males in the emergence of the posterior deciduous dentition. Less is known about sex differences in the dental development and emergence of non-European populations. Here we examine the pattern of sex differences in deciduous tooth emergence in Japanese, Javanese, Guatemalan, and Bangladeshi children. The data come from four longitudinal or mixed longitudinal studies using similar study protocols. Survival analysis was used to estimate parameters of a log-normal distribution of emergence for each of the 10 teeth of the left dentition, and sexual dimorphism was assessed by sex-specific differences in mean emergence times and by Bennett's index. The results support the pattern of developmental cross-over observed in other populations. We conclude that there is little evidence to support the hypothesis of Tanguay et al. ( J. Dent. Res. 63:65-68) that ethnic factors mediate sex differences in the emergence of deciduous teeth.
- SourceAvailable from: Ashley E Stinespring-Harris
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- "Unfortunately , the summary statistics in the Anderson et al.'s publication are of questionable value because the authors used what Smith (1991b) has referred to as ''Method B.'' In ''Method B,'' interval-censored longitudinal data are analyzed by assuming that events occurred at the midpoint of the interval or evenly spaced within the interval if more than one event occurred within an observation window. This approach to analyzing interval-censored data is well known to be problematic (Lindsey and Ryan, 1998), and more appropriate methods are available that have been applied to longitudinal data on dental emergence (Holman and Jones, 1998; Parner et al., 2001; Bogaerts et al., 2002; Holman and Jones, 2003; Leroy et al., 2003; Holman and Yamaguchi, 2005; Yamaguchi and Holman, 2010). "
ABSTRACT: In two historic longitudinal growth studies, Moorrees et al. (Am J Phys Anthropol 21 (1963) 99-108; J Dent Res 42 (1963) 1490-1502) presented the "mean attainment age" for stages of tooth development for 10 permanent tooth types and three deciduous tooth types. These findings were presented graphically to assess the rate of tooth formation in living children and to age immature skeletal remains. Despite being widely cited, these graphical data are difficult to implement because there are no accompanying numerical values for the parameters underlying the growth data. This analysis generates numerical parameters from the data reported by Moorrees et al. by digitizing 358 points from these tooth formation graphs using DataThief III, version 1.5. Following the original methods, the digitized points for each age transition were conception-corrected and converted to the logarithmic scale to determine a median attainment age for each dental formation stage. These values are subsequently used to estimate age-at-death distributions for immature individuals using a single tooth or multiple teeth, including estimates for 41 immature early modern humans and 25 immature Neandertals. Within-tooth variance is calculated for each age estimate based on a single tooth, and a between-tooth component of variance is calculated for age estimates based on two or more teeth to account for the increase in precision that comes from using additional teeth. Finally, we calculate the relative probability of observing a particular dental formation sequence given known-age reference information and demonstrate its value in estimating age for immature fossil specimens.American Journal of Physical Anthropology 02/2012; 147(2):227-53. DOI:10.1002/ajpa.21639 · 2.51 Impact Factor
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- "Variations in the pattern of tooth eruption have also been associated with various socio-demographic variables, one of which is gender; a few studies noted that girls had more erupted teeth than boys (Boas 1927; Magnusson 1982), while some others observed the opposite (Demirjian 1986; Holman & Jones 1998). Other studies had equally shown no gender difference (Enwonwu 1973; Holman & Jones 2003). "
ABSTRACT: The socio-demographic and anthropometric variables could influence the number of teeth present in the child's mouth. To determine the effect of anthropometric and socio-demographic variables on the number of erupted primary teeth, a cross-sectional study was performed involving 1013 children aged between 4 and 36 months who attended the immunization clinics in Ile-Ife, Nigeria. Statistical analyses were performed using STATA. The analyses included frequencies, cross-tabulations, chi squared test and t-test. The number of erupted teeth was modelled as the dependent variable in a multiple regression (Binomial) model, and the socio-demographic (age, gender and socio-economic status) and anthropometric variables, such as weight and height at presentation, as predictor variables. Statistical significance was inferred at P < 0.05. The age and height at presentation had significant association with the number of erupted teeth in this study population (P < 0.001). Also children from high socio-economic class in relation to low socio-economic class had significant larger number of erupted teeth in this study population (P < 0.001). The age and height of the child at presentation were significantly related to the number of erupted teeth. Also children from high socio-economic class had significant lager number of erupted teeth compared with children from low socio-economic class.Maternal and Child Nutrition 01/2009; 5(1):86-92. DOI:10.1111/j.1740-8709.2008.00156.x · 2.97 Impact Factor
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