The evolutionary history of dogs in the Americas.

Dogs were present in the Americas before the arrival of European colonists, but the origin and fate of these precontact dogs are largely unknown. We sequenced 71 mitochondrial and 7 nuclear genomes from ancient North American and Siberian dogs from time frames spanning ~9000 years. Our analysis indicates that American dogs were not derived from North American wolves. Instead, American dogs form a monophyletic lineage that likely originated in Siberia and dispersed into the Americas alongside people. After the arrival of Europeans, native American dogs almost completely disappeared, leaving a minimal genetic legacy in modern dog populations. The closest detectable extant lineage to precontact American dogs is the canine transmissible venereal tumor, a contagious cancer clone derived from an individual dog that lived up to 8000 years ago.

Variability of in vivo linear microcrack accumulation in the cortex of elderly human ribs.

Excessive accumulation of microdamage in the skeleton in vivo is believed to contribute to fragility and risk of fracture, particularly in the elderly. Current knowledge of how much in vivo damage accrual varies between individuals, if at all, is lacking. In this study, paired sixth ribs from five male and five female elderly individuals (76-92 years, mean age = 84.7 years) were examined using en bloc staining and fluorescent microcopy to quantify linear microcracks present at the time of death (i.e. in vivo microdamage). Crack number, crack length, crack density, and crack surface density were measured for each complete cross-section, with densities calculated using the variable of bone area (which accounts for the influence of porosity on the cortex, unlike the more frequently used cortical area), and analyzed using a two-way mixed model analysis of variance. Results indicate that while microcracks between individuals differ significantly, differences between the left and right corresponding pairs within individuals and the pleural and cutaneous cortices within each rib did not. These results suggest that systemic influences, such as differential metabolic activity, affect the accumulation of linear microcracks. Furthermore, variation in remodeling rates between individuals may be a major factor contributing to differential fracture risk in the elderly. Future work should expand to include a wider age range to examine differences in in vivo microdamage accumulation across the lifespan, as well as considering the influence of bisphosphonates on microdamage accumulation in the context of compromised remodeling rates in the elderly.

Intracemetery biological variation at the fort ancient sunwatch village.

OBJECTIVES: We investigate intracemetery biological variation at the Fort Ancient SunWatch village (800-500 BP.) to test the hypothesis that the SunWatch population consisted of spatially structured biologically differentiated kin groups consisting of distinct local Late Woodland and non-local Mississippian biological populations. MATERIAL AND METHODS: The SunWatch sample contains 166 individuals: 63 adults and 103 subadults. We analyze intracemetery biological variation using two feature sets: the buccolingual diameters of the polar teeth in the permanent (n = 37) and deciduous (n = 26) dentitions. We apply matrix correlation models to biodistance and grave distance matrices in both data sets, evaluate burial outliers and individuals exhibiting a rare dental feature with interindividual biological distances, and evaluate potential cultural subgroups with Mahalanobis' distance. RESULTS: Matrix correlation analyses for both feature sets as well as interindividual and subgroup distances indicate the SunWatch village cemetery was kin structured, contained a single primary biological population, and also contained a small number of non-local individuals most of whom were from closely related populations. We thus reject the hypothesis that the SunWatch population consisted of biologically distinct Late Woodland and Mississippian biological populations. DISCUSSION: Although SunWatch village exhibited cultural attributes characteristic of both local Late Woodland and non-local Mississippian groups, biologically the village was composed of one primary population. The lack of evidence for marked biological differentiation in the SunWatch village area at about 800-500 BP. suggests diffusion and acculturation may account for Mississippian cultural characteristics in southwestern Ohio Fort Ancient villages. If gene flow or migrations from biologically distinct Mississippian populations into southwestern Ohio occurred, either or both likely occurred well before 800 BP. This would have allowed the process of admixture time to produce a relatively homogeneous, nondifferentiated population. The latter alternative is consistent with the appearance in southwestern Ohio of non-local individuals at one site linked to surrounding Mississippian regions at about 950 BP. Am J Phys Anthropol 160:719-728, 2016. © 2016 Wiley Periodicals, Inc.

Testing the applicability of six macroscopic skeletal aging techniques on a modern Southeast Asian sample.

Most macroscopic skeletal aging techniques used by forensic anthropologists have been developed and tested only on reference material from western populations. This study examined the performance of six aging techniques on a known age sample of 88 Southeast Asian individuals. Methods examined included the Suchey-Brooks method of aging the symphyseal face of the os pubis (Brooks and Suchey, Hum. Evol. 5 (1990) 227), Buckberry and Chamberlain's, Am. J. Phys. Anthropol. 119 (2002) 231 and Osborne et al.'s, J. Forensic Sci. 49 (2004) 1 revisions of the Lovejoy et al., Am. J. Phys. Anthropol. 68 (1985) 15 method of aging the auricular surface of the ilium, Iscan et al.'s, J. Forensic Sci. 29 (1984) 1094, Iscan et al.'s, J. Forensic Sci. 30 (1985) 853 method of aging the sternal end of the fourth rib, and Meindl and Lovejoy's, Am. J. Phys. Anthropol. 68 (1985) 57 methods for aging both lateral-anterior and vault sutures on the cranium. The results of this study indicate that application of aging techniques commonly used in forensic anthropology to individuals identified as Asian, and more specifically Southeast Asian, should not be undertaken injudiciously. Of the six individual methods tested here, the Suchey-Brooks pubic symphysis aging method performs best, though average age estimates were still off by nearly 10 years or greater. Methods for aging the auricular surface perform next best, though the Osborne et al. method works better for individuals below 50 years and the Buckberry and Chamberlain method works better for those above 50 years. Methods for age estimation from the sternal ends of the fourth rib and vault and lateral-anterior cranial sutures perform poorly and are not recommended for use on remains of Southeast Asian ancestry. Combining age estimates from multiple indicators, specifically the pubic symphysis and one auricular surface method, was superior to individual methods. Data and a worked example are provided for calculating the conditional probability that an individual belongs to a particular age decade, though overall age estimates may still be broad.

Exploring the multidimensionality of stature variation in the past through comparisons of archaeological and living populations.

Adult stature variation is commonly attributed to differential stress-levels during development. However, due to selective mortality and heterogeneous frailty, a population's tall stature may be more indicative of high selective pressures than of positive life conditions. This article examines stature in a biocultural context and draws parallels between bioarchaeological and living populations to explore the multidimensionality of stature variation in the past. This study investigates: 1) stature differences between archaeological populations exposed to low or high stress (inferred from skeletal indicators); 2) similarities in growth retardation patterns between archaeological and living groups; and 3) the apportionment of variance in growth outcomes at the regional level in archaeological and living populations. Anatomical stature estimates were examined in relation to skeletal stress indicators (cribra orbitalia, porotic hyperostosis, linear enamel hypoplasia) in two medieval bioarchaeological populations. Stature and biocultural information were gathered for comparative living samples from South America. Results indicate 1) significant (P < 0.01) differences in stature between groups exposed to different levels of skeletal stress; 2) greater prevalence of stunting among living groups, with similar patterns in socially stratified archaeological and modern groups; and 3) a degree of regional variance in growth outcomes consistent with that observed for highly selected traits. The relationship between early stress and growth is confounded by several factors-including catch-up growth, cultural buffering, and social inequality. The interpretations of early life conditions based on the relationship between stress and stature should be advanced with caution.

Evidence for long-term migration on the Balkan Peninsula using dental and cranial nonmetric data: Early interaction between corinth (Greece) and its colony at Apollonia (Albania).

This article seeks to identify "Greeks" and "non-Greeks" in "mixed" mortuary contexts in a Greek colony. Specifically, we test the hypothesis that Illyrian and Greek individuals lived and were buried together at the Corinthian colony of Apollonia, Albania (established ca. 600 BC). The pattern of human biological interaction at Apollonia is tested by identifying variation in genetic relatedness using biodistance analysis of dental and cranial nonmetric traits for three sites: Apollonia (n = 116), its founder-city Corinth (n = 69), and Lofkënd (n = 108), an inland site near Apollonia pre-dating colonization. Logistic regression analysis estimates that individuals from colonial Apollonia are most closely related to prehistoric Illyrian populations (from Lofkënd and prehistoric Apollonia), rather than Greeks (from Corinth). The phenotypic similarity between colonial Apollonia and prehistoric Illyria suggests that there was a large Illyrian contribution to the gene pool at the colony of Apollonia. However, some trait combinations show low biological distances among all groups, suggesting homogeneity among Illyrian and Greek populations (assessed through pseudo-Mahalanobis' D(2) ). The degree of phenotypic similarity suggests shared ancestry and long-term migration throughout these regions. The impacts of missing data and small sample sizes are also considered.

A comparison of histomorphometric data collection methods.

Although many variables that skeletal biologists examine have been standardized, the actual techniques used to collect these data from bone thin sections vary. This project compares different methods of obtaining data (relative cortical area values) for histomorphometric research. One visual and three digital methods of histomorphometric data collection are compared: (i) Merz microscopic eyepiece counting reticule, (ii) flatbed scanner, (iii) overlaying multiple images of a thin section, and (iv) digital SLR camera with macro settings. The discussion includes a comparison of usability factors such as cost, time, user-experience, and ease-of-use, which vary for each method. Values from the different methods are compared using ANOVA tests to evaluate inter-method, inter-observer, and intra-observer variability. Intra-observer error was greater for the microscopic method, although the error values are concomitant with experience. We found no statistically significant differences between the four methods examined, but certain caveats must be addressed when these methods are used.

Revisiting dental fluctuating asymmetry in neandertals and modern humans.

Previous studies have suggested that Neandertals experienced greater physiological stress and/or were less capable of mitigating stress than most prehistoric modern human populations. The current study compares estimates of dental fluctuating asymmetry (DFA) for prehistoric Inupiat from Point Hope Alaska, the Late Archaic, and Protohistoric periods from Ohio and West Virginia, and a modern sample from Ohio to Neandertals from Europe and Southwest Asia. DFA results from developmental perturbation during crown formation and is thus an indicator of developmental stress, which previous studies have found to be higher in Neandertals than in several modern human populations. Here, we use recent methodological improvements in the analysis of fluctuating asymmetry suggested by Palmer and Strobeck (Annu Rev Ecol Syst 17 (1986) 391-421, Developmental instability: causes and consequences (2003a) v.1-v.36, Developmental instability: causes and consequences (2003b) 279-319) and compare the fit of Neandertal DFA Index values with those of modern humans. DFA estimates for each of the modern population samples exceeded measurement error, with the Inupiat exhibiting the highest levels of DFA for most tooth positions. All significant Neandertal z-scores were positive, exceeding the estimates for each of the modern prehistoric groups. Neandertals exhibited the fewest significant differences from the Inupiat (9.2% of values are significant at P < 0.05), while for the other modern prehistoric groups more than 10% of the Neandertal z-scores are significant at P < 0.05, more than 90% of these significant scores at P < 0.01. These results suggest that the Inupiat experienced greater developmental stress than the other prehistoric population samples, and that Neandertals were under greater developmental stress than all other prehistoric modern human samples.

Intrapopulation variation in stature and body proportions: social status and sex differences in an Italian medieval population (Trino Vercellese, VC).

The phenotypic expression of adult body size and shape results from synergistic interactions between hereditary factors and environmental conditions experienced during growth. Variation in body size and shape occurs even in genetically relatively homogeneous groups, due to different occurrence, duration, and timing of growth insults. Understanding the causes and patterns of intrapopulation variation can foster meaningful information on early life conditions in living and past populations. This study assesses the pattern of biological variation in body size and shape attributable to sex and social status in a medieval Italian population. The sample includes 52 (20 female, 32 male) adult individuals from the medieval population of Trino Vercellese, Italy. Differences in element size and overall body size (skeletal height and body mass) were assessed through Monte Carlo methods, while univariate non-parametric tests and Principal Component Analysis (PCA) were employed to examine segmental and overall body proportions. Discriminant Analysis was employed to determine the predictive value of individual skeletal elements for social status in the population. Our results highlight a distinct pattern in body size and shape variation in relation to status and sex. Male subsamples exhibit significant postcranial variation in body size, while female subsamples express smaller, nonsignificant differences. The analysis of segmental proportions highlighted differences in trunk/lower limb proportions between different status samples, and PCA indicated that in terms of purely morphological variation high status males were distinct from all other groups. The pattern observed likely resulted from a combination of biological factors and cultural practices.

Estimating body mass in subadult human skeletons.

Methods for estimating body mass from the human skeleton are often required for research in biological or forensic anthropology. There are currently only two methods for estimating body mass in subadults: the width of the distal femur metaphysis is useful for individuals 1-12 years of age and the femoral head is useful for older subadults. This article provides age-structured formulas for estimating subadult body mass using midshaft femur cross-sectional geometry (polar second moments of area). The formulas were developed using data from the Denver Growth Study and their accuracy was examined using an independent sample from Franklin County, Ohio. Body mass estimates from the midshaft were compared with estimates from the width of the distal metaphysis of the femur. Results indicate that accuracy and bias of estimates from the midshaft and the distal end of the femur are similar for this contemporary cadaver sample. While clinical research has demonstrated that body mass is one principle factor shaping cross-sectional geometry of the subadult midshaft femur, clearly other biomechanical forces, such as activity level, also play a role. Thus formulas for estimating body mass from femoral measurements should be tested on subadult populations from diverse ecological and cultural circumstances to better understand the relationship between body mass, activity, diet, and morphology during ontogeny.

Stature estimation in an early medieval (XI-XII c.) Polish population: testing the accuracy of regression equations in a bioarcheological sample.

Accurate stature estimation from skeletal remains can foster useful information on health and microevolutionary trends in past human populations. Stature can be estimated through the anatomical method and regression equations. The anatomical method (Fully: Ann Med Leg 36 [1956] 266-273; Raxter et al.: Am J Phys Anthropol 130 [2006] 374-384) is preferable because it takes into account total skeletal height and thus provides more accurate estimates, but it cannot be applied to incomplete remains. In such circumstances, regression equations allow estimates of living stature from the length of one or few skeletal elements. However, the accuracy of stature estimates from regression equations depends on similarity in body proportions between the population under examination and those used to calibrate the equations. Since genetic affinity and body proportions similarity are not always clearly known in bioarcheological populations, the criteria for selection of appropriate formulae are not always straightforward. This may lead to inaccurate stature estimates and imprecise accounts of past life conditions. Prompted by such practical and theoretical concerns this study aimed at (1) estimating living stature in an early medieval (XI-XII c.) Polish sample (40 male; 20 female) through the anatomical method and developing population-specific regression formulae; and (2) evaluating the accuracy of estimates obtained with regression methods commonly employed in European populations. Results indicate that when applied to the skeletal remains from Giecz, our formulae provide accurate estimates, with non-age-corrected formulae performing better than age-corrected ones. Our formulae provide better estimates than those calibrated on recent populations and their use in medieval Polish populations is preferable.

Under restrictive conditions, can the widths of linear enamel hypoplasias be used as relative indicators of stress episode duration?

Linear enamel hypoplasia (LEH), a type of enamel defect reflecting nonspecific physiological stress, has traditionally been used by bioarchaeologists to assess human health. Initially, measurements of defect width were used to estimate the duration of stress episodes. More recently, methods of counting within-defect perikymata (enamel growth increments) were developed to more accurately assess duration. Because perikymata are often not continuously visible within defects, while widths can usually be measured, the primary purpose of this article was to determine if, under restrictive conditions, the widths of LEH defects might be used as relative indicators of stress episode duration. Using a set of dental replicas from the prehistoric Irene Mound (1150-1400 A.D.), this study also investigated potential sources of variation in defect widths and how often defect widths could be measured and within-defect perikymata counted. Of 120 defects, only 47 contained both measurable defect widths and total within-defect perikymata, while 79 had measurable defect widths. Regression analysis revealed that, for these 47 defects, defect widths were more strongly related to the total number of within-defect perikymata than they were to crown region or tooth type. Although wide prediction intervals indicated that a defect's width could not be used to predict the number of within-defect perikymata for an individual, narrower confidence intervals associated with hypothetical mean population widths suggested that mean defect widths might be used to rank populations in terms of relative average stress episode duration.

The History of European Health Project: a history of health in Europe from the late Paleolithic era to the present.

The United States National Science Foundation has recently funded a large collaborative project on "A History of Health in Europe from the Late Paleolithic Era to the Present," whose goal is to measure and analyzes the evolution of skeletal health by combining data from human remains with information gathered from sources in archaeology, climate history, geography, and history. The goal of this international collaborative project is to create a series of database that will allow researchers to reinterpret the history of human health in Europe from the late Paleolithic era to the early twentieth century. During this period, human health and welfare were transformed enormously by the transition from foraging to farming; the rise of cities and complex forms of social and political organization; European colonization; and industrialization. With a trans-Atlantic network of collaborators, we will undertake large-scale comparative studies of the causes and health consequences of these and other dramatic changes in arrangements for work, living, and human interaction.

Dental crown size and sex hormone concentrations: another look at the development of sexual dimorphism.

Previous researchers hypothesized that tooth types forming during early childhood should be less sexually dimorphic than those forming during later childhood, if sex hormone concentration differences between males and females increase progressively throughout childhood and can affect tooth size. Descriptive tooth size data have recently been cited in support of this hypothesis, particularly with respect to differences in sexual dimorphism among the tooth types of tooth classes. The present study tests this hypothesis for the mesiodistal dimension of human permanent teeth using published data for incisor, premolar, and molar tooth classes from seven diverse populations. The sample size for each tooth type per population was at least 50. This study also tests a modification of this hypothesis which takes into account the postnatal testosterone surge in males and the low levels of sex hormones in both sexes prior to puberty. Predictions are developed for both the original and modified hypotheses. The "D" statistic, the total area of nonoverlap between the phenotypic distributions of males and females, is used to quantify sexual dimorphism. Comparison of D values for different tooth types within tooth classes across these seven populations does not strongly support either hypothesis. These results suggest that gross changes in sex hormone concentrations during development are not related to population-wide patterns of sexual dimorphism among the tooth types of human permanent tooth classes, as recent studies indicate. This finding is consistent with other studies which suggest that sex hormones have only a minor role in generating crown size sexual dimorphism.

Variation in limb proportions between Jomon foragers and Yayoi agriculturalists from prehistoric Japan.

Variation in limb proportions between prehistoric Jomon and Yayoi people of Japan are explored by this study. Jomon people were the descendents of Pleistocene nomads who migrated to the Japanese Islands around 30,000 yBP. Phenotypic and genotypic evidence indicates that Yayoi people were recent migrants to Japan from continental Northeast Asia who likely interbred with Jomon foragers. Limb proportions of Jomon and Yayoi people were compared using RMA regression and "Quick-Test" calculations to investigate relative variability between these two groups. Cluster and principal components analyses were performed on size-standardized limb lengths and used to compare Jomon and Yayoi people with other groups from various climatic zones. Elongated distal relative to proximal limb lengths were observed among Jomon compared to Yayoi people. Jomon limb proportions were similar to human groups from temperate/tropical climates at lower latitudes, while Yayoi limb proportions more closely resemble groups from colder climates at higher latitudes. Limb proportional similarities with groups from warmer environments among Jomon foragers likely reflect morphological changes following Pleistocene colonization of the Japanese Islands. Cold-derived limb proportions among the Yayoi people likely indicate retention of these traits following comparatively recent migrations to the Japanese Islands. Changes in limb proportions experienced by Jomon foragers and retention of cold-derived limb proportions among Yayoi people conform to previous findings that report changes in these proportions following long-standing evolution in a specific environment.

Evaluation of juvenile stature and body mass prediction.

This investigation evaluates the performance of juvenile stature (from tibia and radius lengths) and body mass (from breadth of the femoral distal metaphysis) prediction equations based on the Denver Growth Study sample (Ruff C. 2007. Am J Phys Anthropol 133 698-716). The sample used here for evaluation is an independent sample of juveniles brought to the Franklin County (Ohio) Coroner in 1990-1991. The Ohio sample differs somewhat from the Denver reference sample: it includes approximately 25% African-Americans (rather than all European-Americans), a significant number of right limb bones were measured (rather than all left side), it includes a wider range of economic statuses and it includes individuals who died from disease and trauma. As such the composition and measures of the Ohio sample correspond more generally to that seen in skeletal samples so that the accuracy of the estimates from the present sample should approach those found in practical applications of these methods. Results indicate that both juvenile body mass and stature are estimated relatively accurately. Accuracy of body mass estimates for 1-13-year-old juveniles is similar for African-American and European-American males and females. The least accurate estimates are for individuals in the 8-13 years age class (excluding individuals with body mass indices greater than the age specific 95th percentile): n = 9, +/- 2.9 kg, 95% confidence interval 1.4-4.4 kg. Accuracy of stature estimates for 1-17-year-old juveniles is comparable for the tibia and radius and, as with body mass estimates, are similar for African-American and European-American males and females. For combined age, sex, and ancestry groups average accuracies are in the +/-3.5 to +/-6.5 cm range. Some limitations of the methods are discussed.

Brief communication: Comparison of methods for estimating chronological age at linear enamel formation on anterior dentition.

Linear enamel hypoplasia (LEH) is an enamel defect that records the effects of physiological stress on tooth formation. Estimating the age at which LEH defects form is integral to the reconstruction of population health in bioarcheological studies. Two principal methods for aging LEH defects have been introduced in the literature. The conventional approach employs regression equations based on a linear model of tooth growth. The newer, Reid and Dean [Am J Phys Anthropol 113 (2000) 135-139] approach, is based upon a histologically derived curvilinear model of enamel development and therefore likely provides more accurate age estimates. However, the extent to which the Reid and Dean method produces estimated ages at defect formation differing from those of the regression equations has not, until now, been determined. This study quantifies the differences between these two methods. Evaluating the degree to which these methods differ is essential for interpreting the accuracy of LEH age estimates given in previous bioarcheological studies. Age estimates of LEH defects on 338 anterior teeth from the Hamann-Todd osteological sample were calculated using both methods. The resulting estimated ages were compared through a randomized block ANOVA. However, the mean differences between the estimated ages yielded by both methods range from 4 months or less depending on the tooth type with an overall average of 2.63 months. The discussion focuses on the degree to which this difference affects answers to bioarcheological questions.

Relative dental maturity and associated skeletal maturity in prehistoric native Americans of the Ohio valley area.

Estimation of age-at-death of subadults in prehistoric skeletal samples based on modern reference standards rests on a number of assumptions of which many are untestable. If these assumptions are not met error of unknown magnitude and direction will be introduced to the subadult age estimates. This situation suggests that an independent estimate or estimates of age-related features, free of most of the assumptions made when using modern reference standards may be useful supplements in evaluating the age of subadults in prehistoric samples. The present study provides an internally consistent, population-specific measure of maturity for prehistoric Ohio valley Native Americans based on the seriation of dental development that may be used as a supplement to age-estimation. The developing dentition of 581 subadults from eight Ohio valley prehistoric-protohistoric groups was seriated within and among individuals resulting in a sequence of tooth development and a sequence of individuals from least to most mature. Dental maturity stages or sorting categories were then defined based on exclusive, easily observable, and highly repeatable tooth-formation stages. Tooth eruption (into occlusion), bone lengths, and fusion of skeletal elements are summarized by dental maturity stage. This procedure provides maturity estimates for skeletal features ordered by dental maturity stages derived from the same sample thus making explicit the relationship between dental and skeletal maturity.

Dental fluctuating asymmetry in the Gullah: tests of hypotheses regarding developmental stability in deciduous vs. permanent and male vs. female teeth.

In this investigation, deciduous teeth (canines, c; first molars, m1; second molars, m2) and their permanent successors (canines, C; first premolars, P1; second premolars, P2) were used to test two related hypotheses about fluctuating asymmetry (FA). First, based on the biology of the developing dentition, it was predicted that deciduous teeth would be more developmentally stable and thus exhibit less dimensional FA than their permanent successors. Second, based on sex differences in tooth development, it was predicted that female canines would have greater developmental stability (less FA) than male canines. Bucco-lingual measurements were made on dental casts from a single Gullah population. Using a repeated-measures study design (n = 3 repeated measures), we tested these hypotheses on sample sizes ranging from 63-82 antimeric pairs. Neither hypothesis was supported by our data. In most cases, Gullah deciduous teeth did not exhibit statistically significantly less FA than their permanent successors; indeed, statistically significant differences were found for only 3 of 12 deciduous vs. permanent contrasts, and in two cases, the deciduous tooth had greater FA. Female mandibular canines exhibited statistically significantly greater FA than those of males, while there was no statistically significant sex difference in FA for the maxillary canine. FA in these Gullah samples is high when compared to Archaic and late prehistoric Ohio Valley Native Americans, consistent with historical and archaeological evidence that environmental stress was relatively higher in the Gullah population. We suggest that when environmental stress in a population is high, the impact of differences in tooth formation time spans and developmental buffering upon FA may be minor relative to the effect of developmental noise.

Brief communication: discrimination between European-American and African-American children based on deciduous dental metrics and morphology.

This study employs metric and morphological features of the deciduous dentition for discriminating between European-American and African-American children and providing allocation rules (regression equations). Five logistic regression equations are presented, with the percentage of correct allocation to group of between 90.1-92.6%. All five equations employ three metric traits (the mesiodistal diameters of the mandibular deciduous canines and anterior and posterior deciduous premolars) and one morphological feature (cusp number of the maxillary deciduous anterior premolar). In addition to these four variables, only two or three additional morphological features are added in carious combinations in the final equations. Correct allocation to group is 4-12% greater when combining metric and morphological features compared to using the features separately.