Sex Determination Using Tooth Dimensions

Sex determination using maxillary arch width of pediatric population of Namakkal district, India: A forensic study

Aim and Objectives:

The aim of the study is to compute a new formula for sex determination using maxillary arch width of a pediatric population of Namakkal district.

Materials and Methods:

The sample consisted of 146 females and 218 males of South Indian origin aged between 4 and 6 years. Alginate impressions of the upper and lower dental arch were made, and casts were poured immediately. A digital vernier caliper was used to obtain measurements. Arch width at canine, first molar and second molar for both maxilla and mandible were considered for measurement. Statistical analysis was performed using the Statistical Package for the Social Sciences Version 20.0 software.

Results:

The Student's t-test was used to find out the significance between male and female among the different predictor variables at P < 0.05. Significant sexual dimorphism was found in maxillary intercanine width and maxillary first and second intermolar width with conical discriminant function coefficient of 0.732, −0.177 and −0.244, respectively.

Conclusion:

The formula derived from the present study could be of great value in sex determination of pediatric populations of Namakkal district.

Determinación del sexo a través de la métrica dental en cazadores recolectores de la transición pampeano-patagónica oriental / SEX DETERMINATION THROUGH DENTAL METRICS FOR HUNTER-GATHERER GROUPS FROM THE EASTERN PAMPA-PATAGONIAN TRANSITION

<p>El objetivo de este trabajo es evaluar la pertinencia de la métrica dental para obtener información sexual en individuos que habitaron el curso inferior del río Colorado durante el Holoceno tardío (ca. 3000-250 años AP), discutir el grado de dimorfismo sexual e identificar las variables cuantitativas de la dentición que permitan discriminar el sexo de nuevos individuos que se incluyan en futuros análisis. Se estudiaron las medidas máximas bucolinguales y mesiodistales del cuello de los dientes correspondientes a 26 individuos adultos. Las variables más dimórficas corresponden al diámetro bucolingual del canino superior y de ambos segundos molares; en estos casos, las diferencias entre los sexos son estadísticamente significativas. Los resultados obtenidos sobre el dimorfismo sexual se ubican en el extremo superior de los valores correspondientes a diferentes poblaciones humanas. Varios individuos que no contaban con información sexual a través de los métodos tradicionales pudieron ser clasificados desde la métrica dental, lo cual da cuenta del importante potencial de las medidas dentales para contribuir a las caracterizaciones paleodemográficas de conjuntos bioarqueológicos, especialmente en contextos perturbados y con escasa integridad esqueletal.</p><p>Palabras clave: métrica dental; determinación sexual; cazadores-recolectores; curso inferior del río Colorado; Holoceno tardío.</p><p>Abstract<br />The aim of this paper is to evaluate the relevance of dental metrics for obtaining sexual information in individuals who inhabited the lower basin of the Colorado River during the Late Holocene (ca. 3000-250 years BP), to discuss the degree of sexual dimorphism and to identify those quantitative variables adequate for sexual determination of new individuals to be included in future studies. The buccolingual and mesiodistal maximum neck diameters of 26 individual adults were studied. The most dimorphic variables correspond to the buccolingual diameter of the upper canine and both second molars; in these cases, sex differences are statistically significant. The results obtained about sexual dimorphism are located at the upper end of the range for different human populations. Several individuals who had no previous sexual information could be classified using these measurements, which accounts for the significant potential of dental metrics in palaeodemographic characterizations, especially in disturbed bioarchaeological samples.</p><p>Keywords: dental metrics; sexual determination; hunter-gatherers; lower basin of the Colorado River; Late Holocene.</p>

Sex estimation based on deciduous and permanent dentition in a contemporary Spanish population

Sex estimation of skeletal remains with satisfactory allocation accuracy represents an essential step in reconstructing the biological profile of unknown individuals in archaeological research and forensic practice. Teeth are among the most frequently recovered physical elements of an individual that remain after death due to their hardness, durability, and resistance to postmortem insults. This study was based on the deciduous and permanent dentition of 269 individuals (150 males and 119 females) from the Granada osteological collection of identified infants, young children, and adults (Granada, Spain). Mesiodistal, buccolingual, and diagonal crown and cervical diameters of both dentitions were measured, and logistic regression analyses were performed to create equations for sex discrimination. The results show that the first and second deciduous molars and the permanent canines are the teeth with the greatest sexual dimorphism, providing percentages of correct assignment of sex between 78.1 and 93.1% in deciduous dentition and between 79.4 and 92.6% in permanent teeth, depending on the dimensions used. The results indicate that this method may be applicable as an adjunct with other accepted procedures for sex estimation when fragmentary skeletal remains are encountered in archaeological excavations and in forensic contexts.

The metric features of teeth in female-to-male transsexuals

The aim of the study was to evaluate the odontometric characteristics of female-to-male transsexuals (FtM) in comparison to control groups of males and females. A total of 48 FtM, aged 20-28 years, were studied. For each tooth, two standard measurements were taken: the mesiodistal (MD) and the buccolingual (BL) diameter of the crown. Significant differences between males and females were found in BL measures of all maxillary teeth as well as mandibular lateral incisor and canine. Within the MD measures, the most distinguishing were maxillary and mandibular canines and the first molars. For seven teeth, there were a total of 14 comparisons of MD (half for the maxilla and half for the mandible) between the control men and women. Of these, the men had larger diameters for 12, of which four were statistically significant. There were also a total of 14 comparisons of BL diameter; of these, the men had larger diameters for 13, of which nine were statistically significant. For seven teeth, there were a total of 14 comparisons of MD between the control men and the FtM. Of these, the men had larger diameters for 12, of which seven were statistically significant. There were also 14 comparisons of BL; of these, the men had larger diameters for 10, of which six were statistically significant. For seven teeth, there were a total of 14 comparisons of MD between the control women and the FtM. Of these, the women had larger diameters for nine, of which three were statistically significant. There were also a total of 14 comparisons of BL; of these, the FtM had larger diameters for 13, of which five were statistically significant. Our study revealed that the shift of values of metric features in teeth of FtM towards males was more frequent in the more sexually dimorphic BL diameters characterized by significantly greater width of the crown of five teeth: maxillary canine, first and second molars, as well as mandibular incisors. The results showed intermediate status of female-to-male transsexuals' teeth between the males and females, which may suggest a genetic basis of transsexualism.

Matrix decomposition model for investigating prehistoric intracemetery biological variation

A matrix decomposition model for analyzing prehistoric intracemetery biological variability is presented. The model, based on the correlation between interindividual biological and burial distance matrices, provides an estimate of the number of distinct burial populations interred within a single cemetery, which effectively ameliorates identifiability problems typical of general variability analyses (Raemsch [1995] Ph.D. dissertation, SUNY at Albany). Unlike other methods for analyzing intrasite variability analysis (e.g., kinship analysis and microchronology), this method is not reliant on a priori subgroup definition. Assuming a kin-structured burial pattern, a residual matrix is defined based on the raw data matrices; the proportion of negative or zero residuals to the total number of residuals provides an estimate of the number of hidden subgroupings (lineages) within the cemetery. The comparative utility of the model is demonstrated on a series of protohistoric and historic period skeletal samples from the Georgia coast, where it demonstrated that the increase in phenotypic variability during the early mission period is the result of population aggregation at the missions and not necessarily genetic admixture between local and nonlocal groups.