Reliability of aspartic acid racemization rate for chronological age estimation-a systematic review and meta-analysis.

OBJECTIVE: The biochemical approach of dental age using aspartic acid racemization has been widely reported. The aim of this systematic review was to determine the reliability and accuracy of dental age estimation using aspartic acid racemization rate analysis. DESIGN: Eight research databases (PubMed, Google Scholar, Embase, Cochrane, MEDLINE, TRIP, Web of Science, and Scopus) were utilised to gather and assess published literatures in compliance with the PRISMA 2020 guidelines and reported in PROSPERO (CRD42020208877). This systematic review and meta-analysis focused solely on cross-sectional studies. The quality evaluation was performed using the GRADE system. The standardized mean difference between estimated and chronological age was meta-analyzed using the random effects model. RESULT: The literature review yielded 213 studies, of which 26 were considered acceptable for inclusion in this report. Out of 26 studies, 19 presented sufficient evidence for meta-analysis and the remaining 7 were used to construct a qualitative review. According to the meta-analysis, premolar-related studies had the least variability (Tau2 = 0.23; I2 = 72%) among other tooth groups. CONCLUSION: A substantial degree of heterogeneity was found in every type of tooth. Only the premolar teeth had lower degree variability; thus, it is safe to believe that the premolar tooth is the best for this type of age estimation. It is recommended to develop population-specific mathematical equations to improve the accuracy of this age estimation approach.

Digital reconstruction of fragmented tooth remains in forensic context.

Forensic odontology majorly focuses on the identification of victims through the analyses of oral and para-oral structures. Exposure to high temperatures and trauma can occur in mass disasters and may lead to the fracturing and fragmentation of teeth. These fragments may become very fragile and easily damaged while handling. Conventional methodologies such as the use of transparent nail polish, hair spray, cyanoacrylate or adhesives have been used to stabilize the fragmented pieces. This study introduces a new and innovative digital technique that utilizes three-dimensional surface scanning (3DSS) and rapid prototyping techniques to reconstruct fractured portions of the teeth. The results of qualitative congruency analysis suggest that over all variance of morphological error (0.0526 ± 0.05) mm. These results imply that the reconstructed 3D model can be used for various morphometric analyses.

Virtual reality and its transformation in forensic education and research practices.

Documentation and evidence analysis are major components in forensic investigation; hence two-dimensional (2D) photographs along with three-dimensional (3D) models and data are used to accomplish this task. Data generated through 3D scanning and photogrammetry are generally visualised on a computer screen. However, spatial details are lost on the visualisation of 3D data on 2D computer screens. Virtual reality (VR) is an immersive technology that allows a user to visualise 3D information by immersing oneself into the scene. In forensics, VR was particularly introduced for the visualising and plotting distances of crime scenes; however, this technology has wider applications in the field of forensics and for court presentation. This short communication outlines the concept of VR and its potential in the field of forensics.

Assessment of the accuracy of 3D printed teeth by various 3D printers in forensic odontology.

Additive manufacturing technology has benefited many sectors, and its use in forensic sciences has opened up a variety of new opportunities for analysing and exhibiting forensic materials. However, to perform analytical procedures on 3D printed bones and teeth in forensic odontology, the metric and morphological precision of the printed replicas must first be validated. To address this, the present study was undertaken using 12 extracted human teeth that were 3D printed using five different techniques. Manual measurements and a digital mesh comparison were used to evaluate the metric precision of all samples. The findings showed that the printed replicas were accurate to within 0.5 mm of the actual teeth. It was suggested that Digital Light Processing (DLP) prints be used for potential forensic odontology applications based on measurements, digital comparison, and ease of use.

Geometric morphometric analysis for sex determination using lateral cephalograms in Indian population: A preliminary study.

BACKGROUND: Orthodontic science centers primarily on the growth, development and advancement of the craniofacial structures. Geometric morphometrics (GMM) is a new approach for shape identification in forensic sciences. PURPOSE: The aim of this study was to examine the shape variation in the Indian sample in order to assess sexual dimorphism by application of two-dimensional GMM. MATERIALS AND METHODS: The sample comprised a total of 105 lateral cephalograms (54 males-51 females) of Angle's Class I malocclusion patients that were later subjected to principal component (PC) analysis and discriminant analysis. RESULTS: The PC analysis showed over 96% of shape variation. The initial three PCs were statistically significant that depicted as 58.37% of total shape variability, with PC1 represent for the most significant variance 28.48%, PC2 described 18.83% and PC3 11.06%. CONCLUSION: Sex of an individual was clearly associated with occlusion of teeth and showed considerable variation. GMM is an alternative research tool and can be utilized for diagnosing individual characterization and classification of malocclusion.

A literature review on dental autopsy - an invaluable investigative technique in forensics.

Forensic odontology is a specialty of dental sciences that deals with dental evidence in the interest of the justice system. The science of autopsy has been developing from the ancient times even before the popularization of general medicine. The objective of a medico-legal autopsy is to identify significant clues for an ongoing forensic investigation. However, in certain circumstances, it is difficult to conduct an oral examination owing to the anatomic location of the oral cavity. The onset of rigor mortis after death poses further complications. Thus, skillful and sequential dissections of the oral and para-oral structures are required to expose the dentition. Dental autopsy includes incisions and resection of the jaw for the detailed examination of the oral cavity. The procedure involves various modes of examination, including visual and radiographic, which help in human identification in forensic investigation. The present paper provides an overview of the various methods of dental autopsy.

A preliminary study to quantify the efficacy of 3D data acquisition for human bone replication.

BACKGROUND: Three-dimensional imaging is a rapidly growing technology that has revealed exciting insights in disparate fields of research, especially in medicine, forensics, and archaeology. Recent advancements in this technology have also made a remarkable impact in the field of anthropology and odontology. A major benefit of this technology is that they offer effective methods of creating digital records that can aid in physical documentation and can be digitally stored for later assessment and research. AIM: The aim of the current study is to evaluate the metric accuracy of 3D models generated using three different 3D acquisition techniques for performing metric analytical procedures. MATERIALS AND METHOD: Twenty standard craniometric linear measurements (using both sliding and spreading callipers) were taken on two craniums and eight standard measurements were taken on 2 mandibles (using sliding callipers and a mandibulometer); these measurements were then replicated on 3D digital models. RESULTS: Statistical analysis of these dataset using Analysis of Variance (ANOVA) and post hoc Bonferroni test suggested that the physical and virtual measurements were accurate, comparable, and concordant (p > 0.05). CONCLUSION: These findings open up numerous avenues for future study, especially in the fields of forensics and clinical studies. However, in order to overcome the limitations faced in using the digital method certain standardised protocols and guidelines must be established to record these data.

A detailed review of forensic facial reconstruction techniques.

Facial reconstruction is an effective forensic technique that can help recreate a victim's facial appearance from the skull. It is typically used to assist law enforcement agencies to identify missing deceased persons. Reconstruction techniques are usually based on the relationship between the underlying hard tissues, such as bone structure, and soft tissues such as the facial muscles and facial features. Facial reconstruction can be a feasible alternative to identify the remains from a decomposed, mutilated, or skeletonised corpse. It is important to remember that although the outcomes are empirical in nature, the technique has been applied widely in many situations. Recent advancements in technology and computer-based techniques have increased the accuracy and validity of this forensic discipline. We consider the most commonly used facial reconstruction techniques in this paper, with a detailed description of manual 3D techniques.

Mental health of forensic odontologists in Covid-19: An Indian perspective.

Forensic autopsies provided guidance and clarification on the transmission of and the safety of working with Covid-19. However, the outbreak induced not just a socio-economic crisis, but a fast-paced psychological distress worldwide. Various psychological and mental health problems, including stress, anxiety, depression, frustration and uncertainty, have gradually emerged. This article brings attention to the mental health of forensic odontologists during the pandemic.

Forensic Identification of Endodontically Treated Teeth after Heat-Induced Alterations: An In Vitro Study.

OBJECTIVE: The study aimed to highlight the relationship between forensic science and endodontics by illustrating CBCT records can be used as legal evidence for forensic analysis and evaluate the effect of elevated temperature on the endodontically treated teeth. METHODS: The present study was conducted on 40 extracted permanent mandibular premolars, which were divided into two groups based on predetermined incineration temperature: Group I - 400°C & Group II - 800°C subjected for 15 minutes holding time in a digital burnout furnace. The root canal treatment was performed for both the groups and a Pre-incineration CBCT scan was taken for both the groups as an ante-mortem data. Following heating analysis, root canal treated teeth were examined using a stereomicroscope at 20x resolution to evaluate the morphological changes. The post-incineration CBCT scan was taken as the post-mortem record for each group. Both ante-mortem records and post-mortem records were compared for the forensic analysis. RESULTS: The endodontically treated teeth display a series of macroscopic and stereo-microscopic changes for each temperature scale. The CBCT records identify the thermal stress-induced 3D alterations in the gutta-percha filled teeth. CONCLUSION: Knowledge of changes in human dentition and traces of the endodontically treated teeth can help forensic experts for the identification of the fire victims.

Tattoo in forensic science: An Indian perspective.

BACKGROUND: - Tattoos refer to various skin markings done by impregnating the skin's epidermis with varied pigments. In forensic science, tattoos are considered as secondary identification markers and can be used for positive identification. Indian society is a unique blend of traditional and modern religious and social practices. Thus, traditional tattoos are still prevalent among various tribal societies and scheduled castes spread throughout various parts of India. The tribal tattoos can be used to determine tribal affiliations, that can aid in the process of forensic identification. On the other hand, tattoos comprising Western-influenced designs as well as individuals co-opting traditional designs gradually are becoming more popular in urbanized India. Understanding and documenting the various tattoo patterns prevalent throughout the tribal population and the modern metropolitan cities can help create a reference base line data for future forensic identification.

Effective approaches to three-dimensional digital reconstruction of fragmented human skeletal remains using laser surface scanning.

The preservation and reconstruction of anthropological and archaeological remains has been given considerable attention in recent years, particularly within the fields of forensic science and palaeoanthropology. However, few studies have tapped the potential of using 3D technology to reconstruct, remodel and recontour remains and artefacts for the purpose of human identification. The aim of this study was to use 3D technology for the reconstruction and remodelling of fragmented and missing elements of skeletal remains. This project presents the application of three dimensional (3D) modalities to two different simulated forensic case scenarios where an attempt was made to remodel the missing element of the human cranium and reconstruction of fragmented replicated human mandible was performed. The accuracy of the reconstructed model was affirmed based on the anatomical features and digital analysis and methods for use in forensic practice are recommended.

Qualitative assessment of the dental groove pattern and its uniqueness for forensic identification.

INTRODUCTION: Teeth are invaluable in both the living and the deceased for forensic identification and profiling purposes. The occlusal surface patterns in the molars of an individual depend on both intrinsic and extrinsic factors. The individualistic nature of the groove pattern can be used to determine the identity of an individual by the process of comparative identification. AIM AND OBJECTIVE: The objective of this study is to determine the uniqueness of the groove pattern among individuals by the means of digital analysis. MATERIALS AND METHODS: An experimental study was conducted on 80 dental casts where the occlusal groove patterns of 1st and 2nd molars from each cast were traced digitally using image analysis software GIMP (v 2.10.6). The traced patterns were then examined to determine their uniqueness. RESULTS: The most common groove patterns for the maxillary 1st and 2nd molars were found to resemble "Branched H" and "H", respectively. "Y" pattern was observed to be the most common in mandibular 1st molar, whereas mandibular 2nd molar most commonly exhibited "+" pattern. No two groove patterns were similar in the analysis. CONCLUSION: Digital method of analysis is preferable over conventional manual methods as it is noninvasive and precise. The individualistic nature of occlusal groove patterns may play an important role in comparative forensic identification.

Tooth reconstruction in forensic situations through dental materials: An anatomical art.

INTRODUCTION: Dental identification is a frequently applied method of forensic investigation, in mass disasters, accidents, and criminal investigations, where the human remains are decomposed, charred, or skeletonized. However, in such events, teeth may dislodge due to postmortem loss or mishandling during transporting and packaging which may further hamper with the identification of an individual. AIM: To investigate the potential for reconstruction of missing teeth utilizing dental materials. SUBJECTS AND METHODS: Impressions of the intra-alveolar morphology of the empty sockets of a mandible were taken utilizing different impression materials. Positive replicas were prepared, and the profile of the missing/absent dental roots and crowns was constructed. Standardized radiographs were taken to assess the reliability of the method. RESULTS: Based on the subjective observation, the combination of light body and heavy body (Putty)-addition silicone (for negative replica), self-cure (pink-colored) resin (for positive replica), and flowable composite resin (for reconstruction) gave the best outcome among the materials used. CONCLUSION: Tooth reconstruction utilizing dental materials that may help in comparative identification.