Akiko Kumagai

Dental age estimation (DAE) is a well-established procedure in current practice, and it is frequently required in forensic and legal investigations. This study aimed to evaluate the intra- and inter-observer reliability of dental development staging among forensic practitioners using two widely applied staging systems, according to Demirjian et al. 1973 and Moorrees et al. 1963. The study included 250 anonymized panoramic radiographs of individuals between 6 and 14 years (median age, 10 years), comprising 51.2% males and 48.8% females. Eighteen observers with prior training in DAE independently assessed tooth development on panoramic radiographs using the Demirjian and Moorrees methods, with each method evaluated in two separate rounds. Intra-observer reliability was evaluated using weighted and unweighted Cohen’s Kappa, while inter-observer agreement was assessed using Gwet’s AC1 and AC2 coefficients. Weighted analyses accounted for the ordinal structure of developmental stages, whereas unweighted analyses reflected exact agreement. Intra-observer reliability was consistently high across both systems, with median weighted Cohen’s Kappa values ranging from 0.897 to 0.957 and median unweighted Cohen’s Kappa values ranging from 0.836 to 0.944. Inter-observer agreement values averaged across rounds assessed with Gwet’s AC2 ranged from 0.914 to 0.987, whereas mean Gwet’s AC1 ranged from 0.306 to 0.908, indicating that disagreement was primarily due to adjacent-stage differences. Moorrees staging showed slightly higher reliability under weighted conditions, while Demirjian demonstrated higher exact agreement under unweighted conditions. Agreement increased with the number of observers but reached a plateau at approximately 8–10 observers, suggesting an optimal number of observers for forensic consensus. The results indicated that difficulty in distinguishing adjacent stages, unclear stage boundaries, and overlapping anatomical structures were the main sources of uncertainty. The Moorrees system was perceived as more complex, while Demirjian showed difficulty focused on the root development stages. These findings highlight the importance of methodological considerations in dental age estimation and suggest that refinement of staging systems may further improve the reliability of expert assessment.

In forensic contexts, age assessments constitute matters of substantial legal consequence, particularly in proceedings involving children and young adolescents. Dental age estimation (DAE) techniques are widely used for this purpose, especially in cases involving undocumented minors. This study assesses intra- and inter-observer reliability across four well established radiographic systems for dental analysis.: Gleiser and Hunt Modified by Köhler (GHK), Demirjian (DEM), Kullman (KUL), and Cameriere’s Third Molar Maturity Index (I3M). A total of 50 panoramic radiographs from individuals aged 14-23.99 years were analyzed by nine qualified forensic experts. The observers assessed the development stages of third molars using the three staging methods (GHK, DEM, KUL) and measured the I3M using Cameriere's metric approach. Primarily, the quantitative assessment for analyzing the agreement was Cohen’s Kappa, Gwet’s Agreement Coefficient (AC1) and (AC2), and Intraclass Correlation Coefficient (ICC). Statistical analysis revealed high intra-observer reliability for all methods, with coefficient values indicating strong agreement among individual observers. In terms of inter-observer reliability, the I3M achieved the highest agreement (ICC 0.986), followed by DEM (AC2 0.918), GHK (AC2 0.914), and KUL (AC2 0.868). Notably, maxillary third molars consistently showed lower inter-observer agreement than mandibular third molars, particularly when assessed using the DEM and GHK methods. The highest inter-observer agreement in cases where a tooth could not be staged or measured was observed for the KUL method (AC1 0.993), followed by I3M (AC1 0.988), with DEM and GHK, demonstrating equivalent levels of agreement (AC1 0.954). All of the tested methods yielded highly reliable results, especially DEM and GHK. The choice of a staging method should be guided by the specific objectives of each study. Moreover, while the I3M method demonstrated high reliability values, obtaining identical repeated measurements was nearly impossible due to its metric approach.

Assigning a developmental stage is the most subjective step in dental age estimation. Therefore, clear stage definitions and proper observer calibrations are essential or high reliability and reproducibility. In this study, the reliability of the Demirjian method was assessed among 8 experts in DAE. The sample used were panoramic radiographs consisting of 50 healthy patients aged between 15 and 13.99 years old. Seven permanent teeth on the left side in both maxilla and mandible were selected to be examined. Further reference to both reliability and reproducibility will be referred as “reliability”. The intra- and inter-rater reliability was assessed using Cohen’s Kappa and Gwet’s AC1/AC2 value for the overall tooth type, and specific tooth reliability. The intra-rater reliability gives an excellent reliability within observers ranging from 0.86 to 1. The inter-rater reliability was 0.962, with no difference between maxilla (0.950) and mandible region (0.954). Additionally, it was observed that canines and premolars have a lower agreement (0.934) compared to incisors and molars. Further detailed analysis for each tooth gives the lowest reliability to FDI 32 (0.868). Although the Demirjian staging method offers robust reliability for DAE with an emphasis on standardized protocols and examiner calibration, the performance of staging varies across different tooth types.

Despite recent technological and methodological progress in the field of forensic sciences, their application is often rendered impossible in the context of humanitarian crises due to insufficient infrastructure, time and trained personnel, among other factors. Based on the account of a forensic odontologist and an interdisciplinary study combining forensic and social anthropology, this article describes the way in which the victims of the 2011 Great Eastern Japan Earthquake and tsunami were managed and identified. The article exposes various challenges and issues that were encountered by professionals and non-professionals who managed the deceased. Additionally, this research highlights the importance of adjusting international forensic protocols to meet local needs, allowing affected communities to mourn their losses and reduce psychological stress for those handling the bodies. Overall, this study demonstrates the importance of an interdisciplinary approach that includes social anthropological expertise at the beginning of disaster victim identification operations and humanitarian forensic action.

Forensic odontology (FO) plays a crucial role in legal and humanitarian investigations, providing expert testimony and contributing to disaster victim identification (DVI). However, comprehensive global data on the demographics, distribution, and professional activities of forensic odontologists (FOs) remain limited. This pilot study aimed to explore the global landscape of FO by examining the demographic profiles, geographic distribution, professional engagement, and career trajectories of practitioners in the field. A descriptive cross-sectional design was employed, utilizing a 26-item self-administered online questionnaire developed via Microsoft Forms. The survey, comprising both open-ended and multiple-choice questions, was disseminated globally to FOs and FO students through WhatsApp®, LinkedIn®, ResearchGate®, and professional associations' email lists. A total of 206 qualified FOs and students participated in the study. The results indicated that 40.3% of respondents practice in regions where FO is formally recognized as a specialty, with notable regional disparities. Although a significant proportion reported involvement in forensic casework, 27.7% expressed dissatisfaction with the level of support and professional recognition. One of the most pressing barriers identified was the absence of FO in undergraduate dental curricula and the limited availability of specialized training programs. The survey also underscored the diverse professional roles of FOs, including participation in court proceedings, mass disaster response, and forensic research. Key challenges reported by respondents included limited recognition of the field (21.8%), restricted career opportunities (18.4%), and inadequate access to training resources (13.1%). Additionally, specific technical challenges—such as bite mark analysis and dental age estimation—were highlighted as areas requiring further attention. This study offers valuable insights into the geographic distribution and professional scope of FOs, providing a foundation for future research with expanded outreach to ensure a more globally representative sample.

This study attempts to classify ear morphology for human identification in forensic investigations by distinguishing between the upper auricle and lobule areas. A three-dimensional homologous model of the ear was created using 414 ear images of males aged 17–93 years reconstructed from computed tomography scans of forensic autopsy cases. Morphological changes were visualized using principal component analysis and areas of significant individual differences within the entire ear were identified. The classification criterion images for the upper auricle (ten images) and lobule (12 images) were developed by combining multiple principal component values: components 1–5 for the upper auricle and 1–6 for the lobule. Three-dimensional ear images of the upper auricle and lobule areas from 414 subjects were categorized using a measurement method based on the minimum distance between 5,507 corresponding points. The results indicate the applicability of the criterion images for the morphological classification of ears in this study.

Harin Cheong, Akiko Kumagai, Sehyun Oh, Sang-Seob Lee. Anat Cell Biol 2023;56:474-81. https://doi.org/10.5115/acb.23.140