A new perspective on fluctuating odontometric asymmetry in South African Negroes

Abstract

The present communication introduces a novel statistical method by means of which fluctuating odontometric asymmetry may be broken up into two components: shape and size. This method is then applied to the odontometric data of 106 urban South African Negroes in order to test the postulate that there might be a difference between the levels of shape and size asymmetry. The data show that both components are present. Additionally, it is shown that there are no arcadal differences in the magnitudes of size or shape asymmetry. However, size asymmetry predominates in the anterior dental segment of the maxilla while shape asymmetry predominates in the posterior segment. In contrast, shape is the dominant component of asymmetry in the anterior mandibular teeth while size asymmetry predominates in the postcanine teeth. The present analysis does not show shape to be a superior measure of environmental stress compared to size asymmetry.

Variables affecting dental fluctuating asymmetry in human isolates

“…With regard to the location factor, although the mean asymmetry of the maxillary teeth is greater than that of the mandibular teeth, the differences are not significant. This finding is in concordance with the study of Groeneveld and Kieser (1991) and in contrast with the findings of Garn et al (1966Garn et al ( , 1967, Siege1 and Doyle (19751, Harris and Nweeia (19801, Townsend and Brown (1980), Kieser et al (1986). It therefore seems that the prevailing belief that maxillary teeth are less well canalized and more asymmetric than mandibular teeth needs to be reevaluated.…”

“…No significant differences between the repeat measurements were found by the paired-comparison t-test, and the reliability coefficient was high (0.98). Additionally, the mean absolute error (sum of the absolute differences between the two sets of measurements, divided by the number of teeth measured: Utermohle et al, 1983;Groeneveld and Kieser, 1991), was calculated. The mean absolute error value for BL diameter was 0.0398, a result which is very close to the caliper error and less than that published by Groeneveld and Kieser (BL = 0.083) (1991).…”

“…Recently, Groeneveld and Kieser (1991) examined the presence of size and shape asymmetry in dentition. Their results Since non of the above variables (Type, Dimension, Location) are related to FA, Barlett test and test of homogenity among correlations are expected to be significant to the below subsamples of FA measures PD;DD;UPD;LPD;UDD;LDD.…”

“…The probable causes of and the variables associated with fluctuating asymmetry have been discussed in numerous articles (Townsend and Brown, 1980;Kobyliansky, 1987,1991;Livshits et al, 1988). The majority of the published reports examine the degree of relationship between FA and intrinsic factors (e.g., developmental anomalies, congenital illness) versus extrinsic factors (e.g., temperature, noise), but few papers have dealt with the methodological aspects of FA analysis (Palmer and Strobeck, 1986;Groeneveld and Kieser, 1991).…”

Finger ridge-count asymmetry and diversity in Andean Indians and interpopulation comparisons

“…Bilateral asymmetry has mainly been studied in dental (e.g., Groeneveld and Kieser, 1991;Harris and Nweeia, 1980;Hershkovitz et al, 1987Hershkovitz et al, , 1993Kieser et al, 1986;Townsend and Brown, 1980), anthropometric (Garn et al, 1976;Livshits and Kobyliansky, 1989;Livshits and Smouse, 1993;Malina and Buschang, 1984;Plato et al, 1980;Schell et al, 1985), and dermatoglyphic traits (Jantz, 1975;Karev, 1990;Micle, 1987, 1989;Micle and Kobyliansky, 1987;Roche et al, 1979;Vona and Porcell, 1983). The specific feature of dermatoglyphic characters is that they could not be altered by postnatal environmental influences, in contrast to anthropometric traits.…”