Vertebrate mineralized tissues: A modular structural analysis.

Vertebrate mineralized tissues, present in bones, teeth and scales, have complex 3D hierarchical structures. As more of these tissues are characterized in 3D using mainly FIB SEM at a resolution that reveals the mineralized collagen fibrils and their organization into collagen fibril bundles, highly complex and diverse structures are being revealed. In this perspective we propose an approach to analyzing these tissues based on the presence of modular structures: material textures, pore shapes and sizes, as well as extents of mineralization. This modular approach is complimentary to the widely used hierarchical approach for describing these mineralized tissues. We present a series of case studies that show how some of the same structural modules can be found in different mineralized tissues, including in bone, dentin and scales. The organizations in 3D of the various structural modules in different tissues may differ. This approach facilitates the framing of basic questions such as: are the spatial relations between modular structures the same or similar in different mineralized tissues? Do tissues with similar sets of modules carry out similar functions or can similar functions be carried out using a different set of modular structures? Do mineralized tissues with similar sets of modules have a common developmental or evolutionary pathway? STATEMENT OF SIGNIFICANCE: 3D organization studies of diverse vertebrate mineralized tissues are revealing detailed, but often confusing details about the material textures, the arrangements of pores and differences in the extent of mineralization within a tissue. The widely used hierarchical scheme for describing such organizations does not adequately provide a basis for comparing these tissues, or addressing issues such as structural components thought to be characteristic of bone, being present in dermal tissues and so on. The classification scheme we present is based on identifying structural components within a tissue that can then be systematically compared to other vertebrate mineralized tissues. We anticipate that this classification approach will provide insights into structure-function relations, as well as the evolution of these tissues.

SRY gene isolation from teeth for forensic gender identification-An observational study.

Personal identification in forensics is possible with gender determination using DNA (deoxyribonucleic acid) analysis. DNA isolation from teeth samples subjected to extreme temperatures has been shown to predict the gender of the deceased. However, the literature lacks studies on DNA extracted from tooth samples exposed to freezing temperatures. This study aimed to isolate the SRY gene from the extirpated pulp of teeth that were subjected to varying temperatures for gender identification. Thirty teeth with vital pulps, divided into 3 groups were included in the study. Each group consisted of 5 male and 5 female tooth samples. The groups were exposed to diverse environmental factors for three weeks. Group 1: room temperature (R group); Group 2: high temperature (H group) and Group 3: freezing temperature (F group). Later, DNA was isolated from the pulp tissue, and the SRY gene was amplified using PCR (Polymerase Chain Reaction). The Sensitivity and Specificity of the results were analyzed. SRY gene detected in the study samples identified accurate gender with a 46.70% Sensitivity and 93.30% Specificity. Significant difference was found in the correlation between gene expression and gender among the three groups (p = 1.000). The study validates that dental pulp tissue can be a reliable source for DNA extraction. And SRY gene amplification from teeth exposed to diverse environmental conditions. Further investigations are required to validate its application in forensics.

Extracting the truth through chemical analyses: Early life histories of Victorian-era dental patients in Aotearoa New Zealand.

OBJECTIVES: There are few bioarcheological analyses of life experiences in colonial period Aotearoa New Zealand, despite this being a time of major adaptation and social change. In our study, early life histories are constructed from multi-isotope and enamel peptide analysis of permanent first molars associated with Victorian era dental practices operating between AD 1881 and 1905 in Invercargill. Chemical analyses of the teeth provide insight into the childhood feeding practices, diet, and mobility of the people who had their teeth extracted. MATERIALS AND METHODS: Four permanent left mandibular first molars were analyzed from a cache of teeth discovered at the Leviathan Gift Depot site during excavations in 2019. The methods used were: (1) enamel peptide analysis to assess chromosomal sex; (2) bulk (δ13 Ccarbonate ) and incremental (δ13 Ccollagen and δ15 N) isotope analysis of dentin to assess childhood diet; and (3) strontium (87 Sr/86 Sr) and oxygen (δ18 O) isotope analysis of enamel to assess childhood residency. Two modern permanent first molars from known individuals were analyzed as controls. RESULTS: The archaeological teeth were from three chromosomal males and one female. The protein and whole diets were predominately based on C3 -plants and domestic animal products (meat and milk). A breastfeeding signal was only identified in one historic male. All individuals likely had childhood residences in Aotearoa. DISCUSSION: Unlike most bioarcheological studies that rely on the remains of the dead, the teeth analysed in this study were extracted from living people. We suggest that the dental patients were likely second or third generation colonists to Aotearoa, with fairly similar childhood diets. They were potentially lower-class individuals either living in, or passing through, the growing colonial center of Invercargill.

Performance comparison of four qPCR and three autosomal STR commercial kits from degraded skeletal remains.

This research evaluates the current DNA quantification (Quantifiler™ Trio, PowerQuant®, Investigator® Quantiplex® Pro and InnoQuant® HY Fast) and autosomal STRs amplification kits (GlobalFiler™, PowerPlex® Fusion 6 C, Investigator® 24Plex QS) using 62 degraded skeletal remains from armed conflicts (petrous bone, femur, tibia, and tooth) with several parameters (autosomal small, large, and male target, degradation index, probability of degradation, number of alleles above analytical threshold, number of alleles above stochastic threshold, RFU, peak height ratio, number of reportable loci). The best qPCR/autosomal STRs amplification tandem was determined by comparing quantification results by a DNA quantity estimation based on sample average RFU. InnoQuant® HY Fast was the most sensitive kit, and no significative differences were observed among amplification kits; however, Investigator® 24 Plex QS was found to be the most sensitive in our samples. That is why InnoQuant™ and Investigator® 24Plex QS were determined to be the best tandem.

Isotopic and proteomic evidence for communal stability at Pre-Pottery Neolithic Jericho in the Southern Levant.

As one of the key, long-term occupied sites in the Southern Levant, Jericho was one of the most important early Neolithic centres to witness social and economic changes associated with the domestication of plants and animals. This study applies strontium (87Sr/86Sr), oxygen (δ18O) and carbon (δ13C) isotope analyses to the enamel of 52 human teeth from Pre-Pottery Neolithic (PPN) layers of Jericho to directly study human diet and mobility and investigate the degree of consolidation and the flexibility of social organization of Jericho society in the PPN period. The results indicate only two non-local individuals out of the 44 sampled inhabitants identified by strontium isotope analysis and are consistent with the presence of a largely sedentary community at PPN Jericho with no evidence for large-scale migration. We also construct strontium spatial baselines (87Sr/86Sr map) with local 87Sr/86Sr signatures for the sites across the Southern Levant based on systematic compilation and analysis of available data. In addition, we apply proteomic analysis of sex-specific amelogenin peptides in tooth enamel for sex estimation of the sampled individuals (n = 44), the results of which showed a sex-biased ratio (more male than female detected in this sample pool) in Jericho society during the PPN period, which may be due to the limited sample size or selective ritual practices like particular burial zones used for specific groups. We also pretreated a batch of human bone samples recovered from PPNB Jericho for stable carbon and nitrogen isotope analyses for dietary investigations. However, the extracted collagen showed poor preservation and no valid δ13C or δ15N data were obtained.

Investigating mobility and pastoralism in Kerma-period communities upstream of the fourth cataract, Sudan.

OBJECTIVES: The Kingdom of Kush in today's northern Sudan and southern Egypt (ancient Nubia) is often depicted as a secondary state relative to ancient Egypt. More recent investigations have set aside Egyptocentric and western, colonialist perspectives of state development focused on control of land and agricultural surplus, examining Kushites through the lens of African-based models of mobile pastoralism in which power and authority were achieved through control of herds and alliance-building. Here, analyses of radiogenic strontium isotopes in human dental enamel are used to investigate diachronic shifts in mobility patterns linked to pastoralism and state development during the Kerma period (ca. 2500-1100 BCE). MATERIALS AND METHODS: From five cemetery sites around al Qinifab, Sudan, upstream of the capital at Kerma, we analyzed the strontium isotope ratios of 50 teeth from 27 individuals dating from the Early through Late Kerma phases. RESULTS: Individuals from the Early and Middle Kerma phases demonstrated considerable 87 Sr/86 Sr ratio variability (mean = 0.70835 ± 0.00109), with 50% falling outside the locally bioavailable strontium range. Conversely, most Classic (0.70756 ± 0.00043) and Late Kerma (0.70755 ± 0.00036) individuals exhibited ratios consistent with the local region. DISCUSSION: These changes indicate a potential transformation in subsistence strategies and social organization as early communities engaged in a more mobile lifestyle than later groups, suggesting a greater degree of pastoralism followed by declining mobility with Kushite state coalescence and a shift to agropastoralism. Because 87 Sr/86 Sr ratios from enamel reflect childhood geographic residence, these findings indicate that mobility likely involved extended family groups, and not just transhumant adults.

[Chromatographic analysis of hard tooth tissue to determine the age of personality]. / Khromatograficheskii analiz tverdykh tkanei zuba v tselyakh opredeleniya vozrasta lichnosti.

The biochemical approach for age assessment is most appropriate in forensic medicine, as racemization of aspartic acid in bones and teeth is closely related to human biological age. The aim of the study is to assess the biochemical parameters of aspartic acid in human teeth, which can be implemented into forensic practice in Russia. Samples of dentin in amount of 20, taken from the teeth of subjects aged between 16 and 76, were examined. Chromatographic analysis of the samples was performed on a gas chromatograph using chiral column. Statistical data processing showed that the relative squared peak of D-aspartic acid has a strong correlation with human biological age. Data, obtained from the Russian population study, demonstrate the applicability of chromatography for forensic purposes. It should be noted that the approach to the racemization rate estimation in the hard tooth tissue was performed using standard laboratory equipment, which allows to easily implement this method in forensic medical practice.

Brief Communication: Elemental Models of Primate Nursing and Weaning Revisited.

Objectives: Intra-tooth patterns of trace elements barium (Ba) and strontium (Sr) have been used to infer human and nonhuman primate nursing histories, including australopithecine and Neanderthal juveniles. Here we contrast the two elemental models in first molars (M1s) of four wild baboons and explore the assumptions that underlie each. Materials and Methods: Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was employed to create comprehensive calcium-normalized barium and strontium (Ba/Ca, Sr/Ca) maps of M1 enamel and dentine at 35 micron resolution. Results: Postnatal Ba/Ca values were typically high, peaking ~0.5 years of age and then decreasing throughout M1 crown formation; all four individuals showed minimal Ba/Ca values between ~1.2-1.8 years, consistent with field reports of the cessation of suckling. Enamel Sr/Ca did not support patterns of previous LA-ICP-MS spot sampling as the enamel rarely showed discrete Sr/Ca secretory zonation. Increases in Sr/Ca appeared in coronal dentine beginning ~0.3 years, with varied peak value ages (~0.7-2.7 years) and no evidence of a predicted postweaning decline. Discussion: Inferences of baboon weaning ages from initial Ba/Ca minima are more congruent with behavioral observations than Sr/Ca maxima; this is consistent with studies of captive macaques of known weaning ages. Elemental variation is more apparent in the coronal dentine than the enamel of these baboons, which may relate to its more rapid mineralization and protection from the oral environment. Inferences of nursing histories from enamel Sr/Ca patterns alone should be reconsidered, and elevated values of Ba/Ca and Sr/Ca in teeth formed after weaning require further study.

Diagnostic models to predict nuclear DNA and mitochondrial DNA recovery from incinerated teeth.

Teeth are frequently used for human identification from burnt remains, as the structure of a tooth is resilient against heat exposure. The intricate composition of hydroxyapatite (HA) mineral and collagen in teeth favours DNA preservation compared to soft tissues. Regardless of the durability, the integrity of the DNA structure in teeth can still be disrupted when exposed to heat. Poor DNA quality can negatively affect the success of DNA analysis towards human identification. The process of isolating DNA from biological samples is arduous and costly. Thus, an informative pre-screening method that could aid in selecting samples that can potentially yield amplifiable DNA would be of excellent value. A multiple linear regression model to predict the DNA content in incinerated pig teeth was developed based on the colourimetry, HA crystallite size and quantified nuclear and mitochondrial DNA. The chromaticity a* was found to be a significant predictor of the regression model. This study outlines a method to predict the viability of extracting nuclear and mitochondrial DNA from pig teeth that were exposed to a wide range of temperatures (27 to 1000 °C) with high accuracy (99.5-99.7%).

Reconstructing Middle and Upper Paleolithic human mobility in Portuguese Estremadura through laser ablation strontium isotope analysis.

Understanding mobility and landscape use is important in reconstructing subsistence behavior, range, and group size, and it may contribute to our understanding of phenomena such as the dynamics of biological and cultural interactions between distinct populations of Upper Pleistocene humans. However, studies using traditional strontium isotope analysis are generally limited to identifying locations of childhood residence or nonlocal individuals and lack the sampling resolution to detect movement over short timescales. Here, using an optimized methodology, we present highly spatially resolved 87Sr/86Sr measurements made by laser ablation multicollector inductively coupled plasma mass spectrometry along the growth axis of the enamel of two marine isotope stage 5b, Middle Paleolithic Neanderthal teeth (Gruta da Oliveira), a Tardiglacial, Late Magdalenian human tooth (Galeria da Cisterna), and associated contemporaneous fauna from the Almonda karst system, Torres Novas, Portugal. Strontium isotope mapping of the region shows extreme variation in 87Sr/86Sr, with values ranging from 0.7080 to 0.7160 over a distance of c. 50 km, allowing short-distance (and arguably short-duration) movement to be detected. We find that the early Middle Paleolithic individuals roamed across a subsistence territory of approximately 600 km2, while the Late Magdalenian individual parsimoniously fits a pattern of limited, probably seasonal movement along the right bank of the 20-km-long Almonda River valley, between mouth and spring, exploiting a smaller territory of approximately 300 km2. We argue that the differences in territory size are due to an increase in population density during the Late Upper Paleolithic.

Testosterone histories from tusks reveal woolly mammoth musth episodes.

Hormones in biological media reveal endocrine activity related to development, reproduction, disease and stress on different timescales1. Serum provides immediate circulating concentrations2, whereas various tissues record steroid hormones accumulated over time3,4. Hormones have been studied in keratin, bones and teeth in modern5-8 and ancient contexts9-12; however, the biological significance of such records is subject to ongoing debate10,13-16, and the utility of tooth-associated hormones has not previously been demonstrated. Here we use liquid chromatography with tandem mass spectrometry paired with fine-scale serial sampling to measure steroid hormone concentrations in modern and fossil tusk dentin. An adult male African elephant (Loxodonta africana) tusk shows periodic increases in testosterone that reveal episodes of musth17-19, an annually recurring period of behavioural and physiological changes that enhance mating success20-23. Parallel assessments of a male woolly mammoth (Mammuthus primigenius) tusk show that mammoths also experienced musth. These results set the stage for wide-ranging studies using steroids preserved in dentin to investigate development, reproduction and stress in modern and extinct mammals. Because dentin grows by apposition, resists degradation, and often contains growth lines, teeth have advantages over other tissues that are used as records of endocrine data. Given the low mass of dentin powder required for analytical precision, we anticipate dentin-hormone studies to extend to smaller animals. Thus, in addition to broad applications in zoology and palaeontology, tooth hormone records could support medical, forensic, veterinary and archaeological studies.

Ancient human DNA recovered from a Palaeolithic pendant.

Artefacts made from stones, bones and teeth are fundamental to our understanding of human subsistence strategies, behaviour and culture in the Pleistocene. Although these resources are plentiful, it is impossible to associate artefacts to specific human individuals1 who can be morphologically or genetically characterized, unless they are found within burials, which are rare in this time period. Thus, our ability to discern the societal roles of Pleistocene individuals based on their biological sex or genetic ancestry is limited2-5. Here we report the development of a non-destructive method for the gradual release of DNA trapped in ancient bone and tooth artefacts. Application of the method to an Upper Palaeolithic deer tooth pendant from Denisova Cave, Russia, resulted in the recovery of ancient human and deer mitochondrial genomes, which allowed us to estimate the age of the pendant at approximately 19,000-25,000 years. Nuclear DNA analysis identifies the presumed maker or wearer of the pendant as a female individual with strong genetic affinities to a group of Ancient North Eurasian individuals who lived around the same time but were previously found only further east in Siberia. Our work redefines how cultural and genetic records can be linked in prehistoric archaeology.

Stress exposure histories revealed by biochemical changes along accentuated lines in teeth.

The regular incremental secretion of enamel and dentine can be interrupted during periods of stress resulting in accentuated growth lines. These accentuated lines, visible under light microscopy, provide a chronology of an individual's stress exposure. Previously, we showed that small biochemical changes along accentuated growth lines detected by Raman spectroscopy, coincided with the timing of medical history events and disruptions of weight trajectory in teeth from captive macaques. Here, we translate those techniques to study biochemical changes related to illness and prolonged medical treatment during early infancy in humans. Chemometric analysis revealed biochemical changes related to known stress-induced changes in circulating phenylalanine as well as other biomolecules. Changes in phenylalanine are also known to affect biomineralization which is reflected in changes in the wavenumbers of hydroxyapatite phosphate bands associated with stress in the crystal lattice. Raman spectroscopy mapping of teeth is an objective, minimally-destructive technique that can aid in the reconstruction of an individual's stress response history and provide important information on the mixture of circulating biochemicals associated with medical conditions, as applied in epidemiological and clinical samples.

Small-scale mobility fostering the interaction networks of Patagonian (Argentina) hunter-gatherers during the Late Holocene: Perspectives from strontium isotopes and exotic items.

During the Late Holocene, hunter-gatherer interaction networks significantly grew in intensity and extension across Patagonia. Although this growth is evidenced by the increased flow of exotic items across the region, the mechanisms behind these strengthening social networks remain unclear. Since evidence suggests that some individuals might have performed long-distance trips, this article aims to address the potential relationship between these individuals and the flows of exotic items in North Patagonia. We analyzed 54 enamel teeth for strontium isotopes and reconstructed their probable mobility using mixed-effect models and isotope-based geographic assignments. We inferred population and individual mobility trends and compared them against the flow of exotic items built from a standardized compilation. Our results indicate that most individuals have isotopic composition compatible with residence within their burial and surrounding areas. However, a few individuals show isotopic composition incompatible with their burial areas, which suggests axes -from the burial location to the most likely isotope integration area- of extraordinary mobility. At the same time, the flows of exotic items overlap with these axes around the eastern sector of the study area suggesting that this location could have been a central point of convergence for people and items. We argue that small-scale socially driven mobility could have played a relevant role as a general mechanism of interaction that fostered and materialized Patagonian interaction networks during the Late Holocene.

Distribution of Elements in Beaver (Castor fiber) Tooth Enamel as a Sign of Environmental Adaptation: the Special Role of Fe, Co, Mg, and Fluorides (F-).

The aim of the study was to investigate the distribution of elements (Ca, Mg, Fe, P, Zn, Na, K, Cu, Cr, Mo, Co, Se) analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES) and fluorides (F-) determined potentiometrically using an ion-selective electrode in the enamel of European beaver (Castor fiber) teeth. Material for the study was tooth enamel collected from lower jaws from the skulls of the animals borrowed from museum collections (animals inhabited north-western Poland). The results of our study indicate the important role of F- as an element that can affect the hardness and strength of beaver tooth enamel. Critical to the function of beaver teeth (i.e., shearing and crushing wood) is the presence of elements such as Fe in the central incisor labial aspect (orange layer of the incisor enamel), Mg in the inner side of the incisor enamel, and Co and F- in the enamel of the molars. Thanks to the high content of these elements, the enamel is durable and the teeth are adapted to the nutritional and ecological characteristics of this mammalian species. Our study on the distribution of elements in the enamel of beaver teeth may also be important for the understanding of the enamel mineralization processes, determining how elements change the properties of the materials, and exploring the relationship between the environment and life history of the beaver.

Combining δ13C and δ15N from bone and dentine in marine mammal palaeoecological research: insights from toothed whales.

Stable carbon (δ13C) and nitrogen (δ15N) isotopic compositions of bone and dentine collagen extracted from museum specimens have been widely used to study the paleoecology of past populations. Due to possible systematic differences in stable isotope values between bone and dentine, dentine values need to be transformed into bone-collagen equivalent using a correction factor to allow comparisons between the two collagen sources. Here, we provide correction factors to transform dentine δ13C and δ15N values into bone-collagen equivalent for two toothed whales: narwhal and beluga. We sampled bone and dentine from the skulls of 11 narwhals and 26 belugas. In narwhals, dentine was sampled from tusk and embedded tooth; in belugas, dentine was sampled from tooth. δ13C and δ15N were measured, and intra-individual bone and dentine isotopic compositions were used to calculate correction factors for each species. We detected differences in δ13C and δ15N. In both narwhals and belugas, we found lower average δ13C and δ15N in bone compared with dentine. The correction factors provided by the study enable the combined analysis of stable isotope data from bone and dentine in these species.

A Neandertal dietary conundrum: Insights provided by tooth enamel Zn isotopes from Gabasa, Spain.

The characterization of Neandertals' diets has mostly relied on nitrogen isotope analyses of bone and tooth collagen. However, few nitrogen isotope data have been recovered from bones or teeth from Iberia due to poor collagen preservation at Paleolithic sites in the region. Zinc isotopes have been shown to be a reliable method for reconstructing trophic levels in the absence of organic matter preservation. Here, we present the results of zinc (Zn), strontium (Sr), carbon (C), and oxygen (O) isotope and trace element ratio analysis measured in dental enamel on a Pleistocene food web in Gabasa, Spain, to characterize the diet and ecology of a Middle Paleolithic Neandertal individual. Based on the extremely low δ66Zn value observed in the Neandertal's tooth enamel, our results support the interpretation of Neandertals as carnivores as already suggested by δ15N isotope values of specimens from other regions. Further work could help identify if such isotopic peculiarities (lowest δ66Zn and highest δ15N of the food web) are due to a metabolic and/or dietary specificity of the Neandertals.

Micro-punches versus micro-slices for serial sampling of human dentine: Striking a balance between improved temporal resolution and measuring additional isotope systems.

RATIONALE: The last decade has seen a dramatic increase in the application of serial sampling of human dentine in archaeology. Rapid development in the field has provided many improvements in the methodology, in terms of both time resolution as well as the ability to integrate more isotope systems in the analysis. This study provides a comparison of two common sampling approaches, allowing researchers to select the most suitable approach for addressing specific research questions. METHODS: Two common approaches for sequential sampling of human dentine (micro-punches and micro-slices) are compared in terms of viability and efficacy. Using archaeological deciduous second molars and permanent first molars, this study demonstrates how the two approaches capture aspects of the weaning process in different ways. In addition, different aspects related to the extraction protocols, such as the thickness of the central slide and the solubilisation step, are also evaluated. RESULTS: While both approaches show similar intra-tooth isotopic patterns, the micro-punches approach is preferable for research that requires a very fine temporal resolution, while the micro-slices approach is best for research where δ34 S values are needed, or when the samples are poorly preserved. In addition, the solubilisation step has a large effect on collagen yield, and, to a lesser extent, on isotopic compositions. Therefore, it is important to ensure that only samples that have undergone the same pre-treatment protocol are directly compared. CONCLUSIONS: We present the pros and cons of the two micro-sampling approaches and offer possible mitigation strategies to address some of the most important issues related to each approach.

Micro-cracks and micro-fractures reveal radular tooth architecture and its functional significance in the paludomid gastropod Lavigeria grandis.

Most molluscan taxa forage with their radula, a chitinous membrane with embedded teeth. The teeth are the actual interfaces between the animal and its ingesta and serve as load-transmitting regions. During foraging, these structures have to withstand high stresses without structural failure and without a high degree of wear. Mechanisms contributing to this failure- and wear-resistance were well studied in the heavily mineralized teeth of Polyplacophora and Patellogastropoda, but for the rather chitinous teeth of non-limpet snails, we are confronted with a large gap in data. The work presented here on the paludomid gastropod Lavigeria grandis aims to shed some light on radular tooth composition and its contribution to failure- and wear-prevention in this type of radula. The teeth were fractured and the micro-cracks studied in detail by scanning electron microscopy, revealing layers within the teeth. Two layers of distinct fibre densities and orientations were detected, covered by a thin layer containing high proportions of calcium and silicon, as determined by elemental dispersive X-ray spectroscopy. Our results clearly demonstrate the presence of failure- and wear-prevention mechanisms in snail radulae without the involvement of heavy mineralization-rendering this an example of a highly functional biological lightweight structure. This article is part of the theme issue 'Nanocracks in nature and industry'.

Dental Anomalies as Identification Strategies for Unknown Human Remains: Literature Review and Applications.

The unique hard and resilient nature of human teeth makes them useful for various forensic odontological examinations. Structural alterations, cultural modifications, pathological variations, and restorative material make them excellent forensic indicators about biological identity of the unknown deceased or living individuals. Variations in the anatomical details of teeth may be imprinted by defective dental development, traumatic damages, pathologies, and nonmasticatory or weaponry use of teeth during an individual's lifetime. Such imprints can be used for comparisons and identification in forensic anthropology. Deliberate dental alterations/modifications and mutilations practiced due to cultural or esthetic purposes have been reported from some contemporary human population groups as well as from some ancient documented skeletal collections. Willful dental modifications have been most commonly done by filling, drilling, grooving, grinding, staining, and chipping. These dental features may be useful only for differentiation of varied anthropological populations, but their forensic utility cannot be ignored, particularly when antemortem dental records are available for comparisons. Various dental developmental anomalies and defects, restorations, pathological signatures, and occupational markers definitely corroborate other methods of forensic identifications, but cannot be used as sole criteria for individualization of unknown human remains retrieved in medicolegal scenarios. This review article attempts to glean information about various characteristic features of teeth and their forensic significance to aid identification of unknown human dental remains found in forensic contexts; its concluding emphasis focuses on the role of such dental individualities in identification strategies for human remains excavated from an abandoned ancient well situated underneath a religious structure at Ajnala (Amritsar), India. The unique dental features, extrinsic staining of anterior teeth, low frequency of dental pathologies, and notched incisors of those excavated remains were suggestive of them belonging to slain sepoy from an historic military regiment.