Application of Trace Elemental Profile of Known Teeth for Sex and Age Estimation of Ajnala Skeletal Remains: a Forensic Anthropological Cross-Validation Study

Body Height Estimation According to Deciduous Dental Crown Height in a Peruvian Sample of Preschool Children

Introduction

Odontometry and body height are distinctive biological traits, making their relationship relevant in the identification of individuals. The objective of this study was to estimate body height according to the height of the crown of deciduous teeth in Peruvian preschool children.

Materials and Methods

This analytical study was applied to a calculated sample of 204 preschoolers between 3 and 5 years of age (34 per sex/age group) with fully erupted upper anterior deciduous teeth (from #53 to #63). Measurements included body height with a stadiometer (106 ± 6.56 cm; 94-123 cm) and crown height from canine to canine (3.06 mm in #62 to 8.13 mm in #53) in models with digital vernier (intraclass correlation coefficient ≥ 0.781). Linear regression models included calculation of the regression coefficient (β) to predict height based on crown height for each deciduous tooth at a significance level of P < 0.05.

Results

There was no correlation between body height and crown height by tooth type in the total sample (P ≥ 0.05), but there was in a 3-year-old female in #52 (r = 0.4: moderate) and a 5-year-old female in #53 and #63 (r = 0.36-0.38: low) (P < 0.05). Body height prediction equations are shown according to crown height per tooth and sex/age groups. The regressions were significant, explaining 13%-18% of 3-year-old females in #53 and #52 (1.85-1.86 cm error) and 5-year-old females in #53, #51, and #63 (4.61 at 4.63 cm error) (P < 0.05).

Conclusions

The odontology method using crown height of the upper anterior deciduous teeth estimated body height in Peruvian girls of 3 and 5 years of age. The teeth are resistant to traumatic forces so these could be used as a body height estimation parameter for forensic human identification.

How teeth can be used to estimate sexual dimorphism? A scoping review

INTRODUCTION

Teeth are biological structures with a high degree of hardness, density, calcification, and capacity to adapt to extrinsic factors at physical, biological, and physiological levels. Subsequently, they resist for a longer period in deteriorating environmental conditions. With dental analysis, it is possible to acquire biographical data about a person. The aim of this scoping review was to identify publications using human teeth tissues to estimate sexual dimorphism.

METHODS

The scoping review was carried out in the following databases: Jstor, Scielo, Science Direct, PubMed, and Scopus, using ten search strategies in English and guaranteeing completeness and reproducibility of the phases stipulated in the PRISMA guide.

RESULTS

143 studies on sexual dimorphism based on dental tissue traits were included, of which 40.6% (n = 58) were done in Asia and 27.2% (n = 39) in America. 80% of the studies (equivalent to 114 articles) focused their observations and measurements on the dental crown; 4.2% in enamel, dentin, and pulp together; 3.5% in dental pulp; 2.1% in the entire tooth; 2.8% in enamel, root, and the enamel-cementum junction, and only 0.7% in dentin and pulp. In addition, 92.3% of the studies used metric methods, while only 4.9% and 2.8% used biochemical and non-metric method respectively.

CONCLUSION

For sexual dimorphism establishment, enamel has been the most analyzed dental tissue in permanent canines and molars mainly. Likewise, the most widely and accurately used methods for this purpose are the metrics, with the odontometry as the most implemented (intraoral or by using dental plaster models, digital scanning or software) with prediction percentages ranging from 51% to 95.9%. In contrast to biochemical methods, that can achieve the highest precision (up to 100%), the non-metric methods, to a less extent, reported prediction percentages of 58%.

Carbon (δ13C) and nitrogen (δ15N) isotope ratios reveal geographic affinity and dietary status of Ajnala skeletal remains: A forensic anthropological study

Stable isotope analysis from bones and teeth has been widely used to estimate the likely geographic locations and dietary status of individuals whose osseous remains have been retrieved from some forensic or bio-archaeological contexts. The carbon and nitrogen stable isotope signatures can provide insights into geographic affinity and dietary habits. Ajnala skeletal remains represent a serious crime against humanity committed in past by colonial rulers and by amateur archaeologists of modern times. In present study, isotopic concentrations of carbon (δ13C) and nitrogen (δ15N) estimated from 21 mandibular molars have been used to estimate the local or non-local status of badly damaged skeletal remains retrieved from an abandoned well at Ajnala (India). The collagen samples having C/N ratio within range of 2.8-3.6 were considered as well-preserved and non-contaminated ones. The isotope concentrations of carbon and nitrogen varied from -18.7‰ to -22.9‰ and +7.6‰ to +11.7‰, with an average of -20.49 ± 1.2‰ and +9.31 ± 1.1‰, respectively. The analysis of the obtained isotope values reflected the consumption of C3/C4 mixed diet by majority of the individuals, and such type of dietary habits are mainly restricted to the reported Indo-Gangatic plain of India to which slain soldiers reportedly belonged to. These observations corroborated the previous observations about the geographic affinity and dietary status of Ajnala individuals. Though C and N isotopes are by and large not the confirmed/direct indicators of geographic origin, they can provide corroboratory information to support other observations narrowing down the dietary habits of individuals of certain specific geographical regions.

Aging and trace elements in human coronal tooth dentine

Teeth are a fundamental tool in forensic odontology for identification in a legal context of those individuals who cannot be identified visually or by other means. Dentine presents physiological exchanges of in trace elements after a period of mineralization and several factors can affect its concentration. The aim of this study was to investigate the concentration of 25 trace elements in the coronal dentine according to sex and type of tooth to determine their relationship with age. A total of 25 trace elements were analyzed in 150 human coronal dentine. Teeth were classified into three age groups, sex and tooth type. The trace elements were grouped as potentially toxic or essential. Inductively Coupled Plasma-Mass Spectrometry and Atomic Emission Spectroscopy were used. The toxic and essential elements were detected in the following order of concentration: Al > Pb > Sn > Li > As > Cd and Ca > P > Mg > Na > S > K > Sr > Zn > Ba > Fe > B > Ti > Mn > Cr > Ni > Cu > Co > Se > V. Our findings show an increase in the concentration of toxic (Pb, Li and Sn) and essential (B, Ba, K, Sr, S and Mg) elements in coronal dentin related to the age of the teeth, regardless of sex. The concentrations of Pb and K in dentin of molars and premolars are the elements that best relate their variations with age. In view of our results, the analysis of these trace elements in dentin in combination with other types of techniques could be established as an element to consider in age dating studies in different forensic situations.