Radiographic morphology of canines tested for sexual dimorphism via convolutional-neural-network-based artificial intelligence

The permanent left mandibular canines have been used for sexual dimorphism when human identification is necessary. Controversy remains whether the morphology of these teeth is actually useful to distinguish males and females. This study aimed to assess the sexual dimorphism of canines by means of a pioneering artificial intelligence approach to this end. A sample of 13,046 teeth radiographically registered from 5838 males and 7208 females between the ages of 6 and 22.99 years was collected. The images were annotated using Darwin V7 software. DenseNet121 was used and tested based on binary answers regarding the sex (male or female) of the individuals for 17 age categories of one year each (i.e. 6-6.99, 7.7.99… 22.22.99). Accuracy rates, receiver operating characteristic (ROC) curves and confusion matrices were used to quantify and express the artificial intelligence's classification performance. The accuracy rates across age categories were between 57-76% (mean: 68%±5%). The area under the curve (AUC) of the ROC analysis was between 0.58 and 0.77. The best performances were observed around the age of 12 years, while the worst were around the age of 7 years. The morphological analysis of canines for sex estimation should be restricted and allowed in practice only when other sources of dimorphic anatomic features are not available.

Identifying teeth and tooth fragments from digital 3D models

Dental anatomy is an essential skill for human identification in forensic odontology. With the advent of technology enabling virtual autopsies, there is scope for virtual consultation by forensic odontologists especially when the expertise is unavailable but needed in zones of conflict or disasters. This study aimed to investigate potential benefits and challenges of identifying intact and damaged teeth from 3D scanned digital models. Ten 3D tooth models - nine permanent and deciduous human teeth and one animal tooth were uploaded on a hosting platform. A 3-part survey was circulated among 60 forensic odontologists with questions about demography (P1), tooth identification of the scanned 3D models (P2) and the perceived usefulness of 3D models for tooth identification (P3). This was the first time that a survey required the identification of individual human teeth (intact or not) and animal tooth combined. The response rate for study participation was 58%. Substantial agreement among participants was seen in the determination of tooth classification (i.e., molars, premolars) or non-human and tooth within the same tooth class (i.e., lateral incisors, second molar) (both k=0.61). The least agreement (k=0.21) was seen in identification of tooth according to the FDI notation with a mean accuracy of 0.34. While most responders correctly identified the animal tooth, most incorrect responses were seen in the identification of the intact third molar. While 3D-scanned teeth have the potential to be identified virtually, forensic odontologists should continuously test their skills in tooth morphology and dental anatomy of humans (damaged or not) and animals.

Dental age estimation methods applied to Indian children and adolescents: A systematic review and meta-analysis

Country-specific systematic reviews and meta-analyses have been proposed to compile the available literature and rank methods based on their performance for a target population. India is a country with a vast scientific literature on dental age estimation. This systematic review aimed to provide evidence to help the decision of experts regarding the method of choice for dental age estimation in India. The research protocol was registered in Open Science Framework. Literature Search was performed in Embase, LILACS, MedLine (via PubMed), SciELO, Scopus and Web of Science. Grey Literature was searched in Google Scholar and ProQuest. Observational cross-sectional studies that compared chronological and estimated ages using Demirjian (original [DEM] and Chaillet's modification [modified-DEM]) and Acharya (ACH) methods were included. JBI tool was used to assess the risk of bias. The search detected 9799 studies, out of which 56 were eligible (n=13,107 panoramic radiographs of Indian individuals). Low risk of bias was registered for 48 studies, while 8 presented a moderate risk of bias. The meta-analysis showed a standardized mean difference between chronological and estimated ages of -0.11 (95%CI: -0.29; 0.07), 0.74 (95%CI: 0.39; 1.09), and -0.01 (95%CI: -0.23; 0.22) years for DEM, modified-DEM and ACH, respectively. High heterogeneity (I2=88-93%) was observed across studies for all the methods, including subgroup analyses based on sex. This study ranked ACH, DEM and modified-DEM (from the best to the worse) performances in the Indian population.

Intersection of forensic odontology and psychology

Forensic odontologists are expected to deal with challenging demands which can affect their mental health while dealing with forensic activities. This study aimed to explore the psychological impacts of forensic activities on forensic odontologists and students undertaking training. Firstly, it of an integrative review (part I) on the psychological effects of forensic odontology practice. The review was performed on Scopus, Medline and Web of Science. Next, an anonymous online survey using JISC Online Surveys tool (part II) was performed to assess the inherent opinions of forensic odontologists from the the International Organization for Forensic Odonto-Stomatology (IOFOS), and Association of Forensic Odontologists for Human Rights (AFOHR), and Dentify.me. Results were quantitatively evaluated by means of descriptive statistics and qualitatively upon reflection using Microsoft Office Excel (2010). Part I, only one full-text article out of 2235 (Webb et al., 2002) was found eligible indicating a low number of eligible studies. Part II, 75 forensic odontologists and 26 students (49.9% male; 50.5% female) from over 35 countries participated. Results showed that forensic dentists are more psychologically or emotionally affected by child abuse cases and least affected by age estimation cases. Most experienced forensic odontologists reported the lowest scores of discomforts. Males were more comfortable than women in dealing with stress. 80.77% (n= 21) of the students have not experienced any behavioural changes following mortuary sessions but 19.2% (n= 5) witnessed stress. All respondents support the inclusion of a module in Psychology or stress management in training programmes in Forensic Odontology. Suggestions to maintain mental health are considered by the respondents and topics to be taught suggested by a psychologist.