Dental identification by comparison of antemortem and postmortem dental radiographs: Influence of operator qualifications and cognitive bias

[Forensic dentistry for identity verification. A survey at the state police level]

BACKGROUND

In Germany, the identification of unknown dead persons is the responsibility of the police. According to INTERPOL standards, primary (e.g., DNA, fingerprints, and teeth) and secondary (e.g., tattoos) characteristics are examined. Forensic dentistry is already used internationally as an efficient method. In this study, the approach of state police in Germany was analyzed. The methods used for identification, the role of forensic dentistry, the cooperation with dentists, and possible optimization approaches are investigated.

METHODS

By means of a digital questionnaire, police officers competent in all federal states for the discovery of unknown dead bodies were asked about identification methods and specifically about the use of forensic dentistry.

RESULTS

Eighty-five officers from at least 11 federal states participated in the survey. The procedure turned out to be department specific. In 72.6% of the cases, different characteristics are combined in the identification process, most frequently DNA with dental status (37.1%). DNA analysis is used most frequently. Of the respondents, 62.9% agreed that dental identification is used "often." The percentage of identifications using dental status is estimated to be 1.6-8.1%. For forensic dentistry, 19.4% have a fixed point of contact. A digital platform to contact dentists was estimated to be helpful by 56.5%.

DISCUSSION

Forensic dentistry is currently still lagging behind DNA analysis, which could change through increasing digitalization if, for example, ante-mortem data are more reliably available and platforms for interdisciplinary exchange are created.

Undergraduate dental students and their potential role in disaster victim identification procedures: A scoping review under a Chilean perspective

BACKGROUND

A mass fatality incident is an unexpected event that can cause the death of many people, which has motivated careful analysis and development of appropriate strategies for planning and response with all available resources. As these events involve multiple victims, their identities must be confirmed using the highest possible quality standards. Forensic Odontology (FO) has proven to be a scientific resource for disaster victim identification (DVI) procedures; however, it is highly dependent on the proper management not only of material resources but also of human resources. Chile is a country recognised as prone to natural disasters, but an insufficient number of forensic odontologists has been reported. The aim of the study was to review the literature on a dental undergraduate (UG) student's potential value in a DVI process.

METHODOLOGY

A scoping review was performed using a specific search strategy in PubMed/Medline, Web of Science, Scopus, SciELO and EBSCO databases.

RESULTS

The search identified 27 articles in which the basic dental degree, the necessary training and the need for human resources are variables considered in different priorities by those articles.

DISCUSSION

It is vital to assess the local needs of Chile based on its UGs, considering that FO is an underestimated resource that should be included early on in dental curriculums. Furthermore, it should align with public policies to ensure viability and inclusion in standardised protocols.

CONCLUSION

Although there is "potential" usage of UG dental students in DVI is not ideal, circumstances will dictate their use. The better trained they are as students, the more valuable their "potential" contribution will be.

Implementation of a personal identification system using alveolar bone images

OBJECTIVE

In recent years, personal identification has been performed using antemortem panoramic X-ray images and postmortem-CT images. Using these, we have developed a personal identification method that focuses on the alveolar bone. This study examined the effectiveness of this method and aimed to implement a reproducible system.

MATERIALS AND METHODS

For personal identification, a total of 633 CT images and panoramic X-ray images belonging to three groups with different conditions were used.　These images were 160 sets in the same person group and 96,820 in the other groups. The similarity of alveolar bone images was calculated using the landmark method of Procrustes analysis. The processes were system implemented and the methodology was validated.

RESULTS

The ability to identify between the same person group and other person groups showed 0.9769 as the area under the curve (AUC: ROC curve). At the cutoff value of 4.978, there was no false rejection rate, but false acceptance rate was slightly higher.

CONCLUSION

This method was useful as a screening method for personal identification. In addition, system implementation was efficient and reduced human error. In the future, we aim to realize a more efficient personal identification method using distortion-corrected images and including auto-detective landmarks using deep learning.

Dental hygiene students' matching accuracy when comparing antemortem dental radiographs and oral photographs to simulated postmortem WinID3® odontograms

Matching dental antemortem (AM) and postmortem (PM) data for human identification is especially challenging when the workforce is limited. Dental hygienists have served mass fatality incidents (MFIs) due to dental-related expertise. However, forensics within dental hygiene education and research on transferable skills is limited. This qualitative balance design study assessed senior dental hygiene students' match accuracy of simulated cases varying in dental identifiers based on AM full mouth series (FMS) radiographs and oral photographs to PM WinID3^® odontograms to demonstrate possible disaster victim identification (DVI) transferable skills gained during formal education. A convenience sample of senior dental hygiene students (n = 31) was presented information on WinID3^® interpretation, then presented with 5 mismatched cases and asked to visually interpret each to make 10 total matches; five based on AM FMS with simulated PM WinID3^® odontograms and five based on AM photographs with PM WinID3^® odontograms. Match accuracy scores ranged from 41.9% to 58.1% for cases with 1-10 identifiers, and 77.4% to 93.5% for cases with 11-40 identifiers. Accuracy when matching AM radiographs to PM odontograms versus AM photographs to PM odontograms was compared and revealed no statistical differences in match accuracy depending on image type (p = 0.388 to 1.000). Results of this pilot study suggests transferable match accuracy skills resulted from the participants' dental hygiene formal education. These baseline skills with additional specialized training support the rationale for dental hygienists serving on DVI teams. More research is needed in education and practice when preparing dental hygienists for forensic-based service.

Human Remains Identification Using Micro-CT, Chemometric and AI Methods in Forensic Experimental Reconstruction of Dental Patterns after Concentrated Sulphuric Acid Significant Impact

(1) Teeth, in humans, represent the most resilient tissues. However, exposure to concentrated acids might lead to their dissolving, thus making human identification difficult. Teeth often contain dental restorations from materials that are even more resilient to acid impact. This paper aims to introduce a novel method for the 3D reconstruction of dental patterns as a crucial step for the digital identification of dental records. (2) With a combination of modern methods, including micro-computed tomography, cone-beam computer tomography, and attenuated total reflection, in conjunction with Fourier transform infrared spectroscopy and artificial intelligence convolutional neural network algorithms, this paper presents a method for 3D-dental-pattern reconstruction, and human remains identification. Our research studies the morphology of teeth, bone, and dental materials (amalgam, composite, glass-ionomer cement) under different periods of exposure to 75% sulfuric acid. (3) Our results reveal a significant volume loss in bone, enamel, dentine, as well as glass-ionomer cement. The results also reveal a significant resistance by the composite and amalgam dental materials to the impact of sulfuric acid, thus serving as strong parts in the dental-pattern mosaic. This paper also probably introduces the first successful artificial intelligence application in automated-forensic-CBCT segmentation. (4) Interdisciplinary cooperation, utilizing the mentioned technologies, can solve the problem of human remains identification with a 3D reconstruction of dental patterns and their 2D projections over existing ante-mortem records.

A fully automated method of human identification based on dental panoramic radiographs using a convolutional neural network

OBJECTIVES

This study aimed to develop a fully automated human identification method based on a convolutional neural network (CNN) with a large-scale dental panoramic radiograph (DPR) data set.

METHODS

In total, 2760 DPRs from 746 subjects who had 2-17 DPRs with various changes in image characteristics due to various dental treatments (tooth extraction, oral surgery, prosthetics, orthodontics, or tooth development) were collected. The test data set included the latest DPR of each subject (746 images) and the other DPRs (2014 images) were used for model training. A modified VGG16 model with two fully connected layers was applied for human identification. The proposed model was evaluated with rank-1, -3, and -5 accuracies, running time, and gradient-weighted class activation mapping (Grad-CAM)-applied images.

RESULTS

This model had rank-1, -3, and -5 accuracies of 82.84%, 89.14%, and 92.23%, respectively. All rank-1 accuracy values of the proposed model were above 80% regardless of changes in image characteristics. The average running time to train the proposed model was 60.9 s per epoch, and the prediction time for 746 test DPRs was short (3.2 s/image). The Grad-CAM technique verified that the model automatically identified humans by focusing on identifiable dental information.

CONCLUSION

The proposed model showed good performance in fully automatic human identification despite differing image characteristics of DPRs acquired from the same patients. Our model is expected to assist in the fast and accurate identification by experts by comparing large amounts of images and proposing identification candidates at high speed.

Use of Advanced Artificial Intelligence in Forensic Medicine, Forensic Anthropology and Clinical Anatomy

Three-dimensional convolutional neural networks (3D CNN) of artificial intelligence (AI) are potent in image processing and recognition using deep learning to perform generative and descriptive tasks. Compared to its predecessor, the advantage of CNN is that it automatically detects the important features without any human supervision. 3D CNN is used to extract features in three dimensions where input is a 3D volume or a sequence of 2D pictures, e.g., slices in a cone-beam computer tomography scan (CBCT). The main aim was to bridge interdisciplinary cooperation between forensic medical experts and deep learning engineers, emphasizing activating clinical forensic experts in the field with possibly basic knowledge of advanced artificial intelligence techniques with interest in its implementation in their efforts to advance forensic research further. This paper introduces a novel workflow of 3D CNN analysis of full-head CBCT scans. Authors explore the current and design customized 3D CNN application methods for particular forensic research in five perspectives: (1) sex determination, (2) biological age estimation, (3) 3D cephalometric landmark annotation, (4) growth vectors prediction, (5) facial soft-tissue estimation from the skull and vice versa. In conclusion, 3D CNN application can be a watershed moment in forensic medicine, leading to unprecedented improvement of forensic analysis workflows based on 3D neural networks.

Quantitative and qualitative evaluation on the accuracy of three intraoral scanners for human identification in forensic odontology

The purpose of this study was to analyze the accuracy of intra oral scanner (IOS) to confirm the applicability of IOS for the recording and analysis of tooth morphology in forensics. The less damaged mandible specimen with many teeth remaining was scanned three times using three types of intraoral scanners (CS3600, i500, and Trios3). For quantitative comparisons of the scanned images produced by these intraoral scanners, root mean square (RMS) values were computed using a three-dimensional analysis program and a one-way ANOVA was conducted with Tukey HSD (honestly significant difference) as a post-hoc analysis (α=0.05). The repeatability of the full scan data was highest with the i500 (0.14±0.03 mm), and the post-hoc analysis confirmed significant differences between the CS3600 and the i500 outcomes (P-value=0.003). The repeatability of the partial scan data for the teeth in the mandible was highest with the i500 (0.08±0.02 mm), and the post-hoc analysis confirmed significant differences between the CS3600 and the i500 (P-value=0.016). The precision of the full scan data was highest with the i500 (0.16±0.01 mm) but the differences were not statistically significant (P-value=0.091). Meanwhile, the precision of the partial scan data for the teeth in the mandible was highest with the Trios3 (0.22±0.02 mm), but the differences were not statistically significant (P-value=0.762). Considering that the scanning of other areas of the oral cavity in addition to the teeth is important in forensic odontology, the i500 scanner appears to be the most appropriate intraoral scanner for human identification. However, as the scope of oral scanning is generally limited to teeth in the practice of dentistry, additional discussions of how to apply the IOS in forensic odontology are needed. Ultimately, the results here can contribute to the overall discussion of the forensic applicability dental data produced by intraoral scanners.

Interpretation, confidence and application of the standardised terms: Identified, Probable, Possible, Exclude and Insufficient in forensic odontology identification

Forensic odontology identification scales are used to express certainty of identifications of deceased persons. These standardized scales are assumed to convey unambiguous expert opinions and facilitate communication between forensic odontologists and end users. However, to date no studies have investigated how the experts interpret and use these scales. Forensic odontology identification scales are used to express certainty of identifications of deceased persons. These standardized scales are assumed to convey unambiguous expert opinions and facilitate communication between forensic odontologists and end users. However, to date no studies have investigated how the experts interpret and use these scales. This paper aims to examine the interpretation of the DVISYS forensic identification scale and choices of the levels in the scale subsequent to, and derived from, comparison of pairs of dental radiographs by extending the analysis of the data collected in the study by Page and Lain et. al. 2017. The studied variables: self-reported confidence, forced binary decision of match and non-match, choice of level in the DVISYS scale (Identified, Probable, Possible, Insufficient and Exclude) were further analysed in this study using mixed models for relationships between the choices of level in the identification scale and the fundamental beliefs of likelihood of identification. The results of this further analysis showed that the reported confidence of the decisions was correlated to the difficulty of cases, and as confidence decreased the use of less definitive terms ('Probable', 'Possible' and 'Insufficient') increased. 'Probable' and 'Possible' were used mainly in underlying beliefs below that of 'Identified' whereas 'Insufficient' was used mainly to convey a sublevel of 'Exclude'. The use of 'Insufficient' in this study was not consistent with the prescribed definition of the term. The participants of the original study were not aware of the difficulty grading of the cases nor were required to grade them, however the reported confidence was systematically correlated to difficulty. Furthermore, indicated confidence level was correlated with choice of level on the scale in general, but the interpretation of the definition and application of the terms varied. The findings reported here contribute to the foundational knowledge of factors governing the interpretation and application of the DVISYS forensic odontology identification scale and suggest that this scale may need to be modified.

Intraoral Scanners in Personal Identification of Corpses: Usefulness and Reliability of 3D Technologies in Modern Forensic Dentistry

Aims:

This study aims to verify the applicability of modern dental technologies and their related principles of use to the forensic sciences in the field of personal identification.

Background:

Personal identification has always had a major role in many legal and administrative actions regarding both living and death beings. The techniques used are much less advanced than the technologies potentially available.

Objective:

Modern technologies, available to the daily dental clinic practice, as intraoral scanners, combined in particular to the specialist skill in orthodontics, can help redefine the methods of personal identification according to the levels of accuracy, trueness and feasibility greater than those applied in traditional forensic dentistry.

Methods:

23 corpses (12F;11M) have been selected for intraoral scanning with the Carestream 3500® digital device. The superimposition of initial and late digital models, digital models and radiographs (orthopantomography and full mouth periapical films) has been evaluated to verify the stability of some structures as palatal rugae after death and to assess intraoral scanning as a successful comparative method between antemortem and post-mortem records (digital models or radiographs). Obtained results were subjected to statistical analysis by the t-student test and X-square test with Yates correction (p<0.05).

Results:

After death, palatal rugae significatively change especially in mouths with restorations/prosthesis/missing teeth. The percentages of correct matching between scans and radiographs are very higher (up 90%; p<0.05).

Conclusion:

This study has been set up to study and develop new, reliable and fast methods of personal identification that can surpass many of the issues seen with the other techniques by a modern rugoscopy, a modern radiographic-digital comparison and virtual oral autopsy.

Intraoral Scanners in Personal Identification of Corpses: Usefulness and Reliability of 3D Technologies in Modern Forensic Dentistry

Aims:

This study aims to verify the applicability of modern dental technologies and their related principles of use to the forensic sciences in the field of personal identification.

Background:

Personal identification has always had a major role in many legal and administrative actions regarding both living and death beings. The techniques used are much less advanced than the technologies potentially available.

Objective:

Modern technologies, available to the daily dental clinic practice, as intraoral scanners, combined in particular to the specialist skill in orthodontics, can help redefine the methods of personal identification according to the levels of accuracy, trueness and feasibility greater than those applied in traditional forensic dentistry.

Methods:

23 corpses (12F;11M) have been selected for intraoral scanning with the Carestream 3500® digital device. The superimposition of initial and late digital models, digital models and radiographs (orthopantomography and full mouth periapical films) has been evaluated to verify the stability of some structures as palatal rugae after death and to assess intraoral scanning as a successful comparative method between antemortem and post-mortem records (digital models or radiographs). Obtained results were subjected to statistical analysis by the t-student test and X-square test with Yates correction (p<0.05).

Results:

After death, palatal rugae significatively change especially in mouths with restorations/prosthesis/missing teeth. The percentages of correct matching between scans and radiographs are very higher (up 90%; p<0.05).

Conclusion:

This study has been set up to study and develop new, reliable and fast methods of personal identification that can surpass many of the issues seen with the other techniques by a modern rugoscopy, a modern radiographic-digital comparison and virtual oral autopsy.

Forensic age estimation based on development of third molars: a staging technique for magnetic resonance imaging

BACKGROUND

The development of third molars can be evaluated with medical imaging to estimate age in subadults. The appearance of third molars on magnetic resonance imaging (MRI) differs greatly from that on radiographs. Therefore a specific staging technique is necessary to classify third molar development on MRI and to apply it for age estimation.

AIM

To develop a specific staging technique to register third molar development on MRI and to evaluate its performance for age estimation in subadults.

MATERIALS AND METHODS

Using 3T MRI in three planes, all third molars were evaluated in 309 healthy Caucasian participants from 14 to 26 years old. According to the appearance of the developing third molars on MRI, descriptive criteria and schematic representations were established to define a specific staging technique. Two observers, with different levels of experience, staged all third molars independently with the developed technique. Intra- and inter-observer agreement were calculated. The data were imported in a Bayesian model for age estimation as described by Fieuws et al. (2016). This approach adequately handles correlation between age indicators and missing age indicators. It was used to calculate a point estimate and a prediction interval of the estimated age. Observed age minus predicted age was calculated, reflecting the error of the estimate.

RESULTS

One-hundred and sixty-six third molars were agenetic. Five percent (51/1096) of upper third molars and 7% (70/1044) of lower third molars were not assessable. Kappa for inter-observer agreement ranged from 0.76 to 0.80. For intra-observer agreement kappa ranged from 0.80 to 0.89. However, two stage differences between observers or between staging sessions occurred in up to 2.2% (20/899) of assessments, probably due to a learning effect. Using the Bayesian model for age estimation, a mean absolute error of 2.0 years in females and 1.7 years in males was obtained. Root mean squared error equalled 2.38 years and 2.06 years respectively. The performance to discern minors from adults was better for males than for females, with specificities of 96% and 73% respectively.

CONCLUSION

Age estimations based on the proposed staging method for third molars on MRI showed comparable reproducibility and performance as the established methods based on radiographs.

The iliac crest in forensic age estimation: evaluation of three methods in pelvis X-rays

Age assessment in children and young adults is a relevant forensic issue. It is requested not only in evaluating criminal responsibility in youths without proper identification documents, often in relation to age thresholds, but also for release of a residency permit, and asylum seekers of minors. The analysis of the Risser sign and the iliac crest ossification process has been proposed as a useful tool for forensic age estimation. We evaluated the applicability of three different age estimation methods on a sample of 497 pelvic radiographs of Italian individuals between 10 and 25 years of age. Each method showed high reliability for both reproducibility and repeatability. The staging technique inspired by Kreitner and Kellinghaus methods (KK-MS) is easier than the Risser method in applicability, as it is not affected by the variations of ossification. We observed that all subjects who attained stage 3c of KK-MS and 5 of Risser Fr were >14 years, suggesting the benefits of these methods for that age threshold. The applicability of the area measurement method, inspired by Cameriere's approach, ranged between 12 and 20 years, but the statistical analysis showed only a moderate correlation with age. In order to evaluate the possible use of this approach it is therefore necessary to clarify and exclude external factors influencing the parameter. In conclusion, the iliac crest ossification is of interest in age estimation for forensic purposes. The evaluation of the pelvis X-ray, in addition to the other common dental and skeletal methods, could become a useful supplementary tool in age estimation for the 14 year threshold in order to fulfill forensic-level requirements.

Multiple deaths caused by a fire in a factory: identification and investigative issues

The article presents a case of multiple casualties following a textile factory fire. The incident required a full DVI team similar to large mass-disaster because of the specific operational aspects and identification difficulties. The autopsy results were consistent with death by fire and the toxicological investigations revealed carbon monoxide poisoning in four cases (HbCO% ranging between 88,05 and 95,77), two deaths by cyanide intoxication (with concentrations between 5,17 and 8,85 mcg/ml), and in one case there was a synergistic effect of the two substances (carbon monoxide and cyanide). The identification, carried out in accordance with INTERPOL protocols, encountered serious difficulties in the AM phase primarily due to a language barrier and the lack of any dental or medical information relating to the victims. Secondary identifiers proved to be very useful in corroborating possible identities. As a result of the combined efforts of a team of experts the identity of each victim was determined and in all cases at least one primary identifier was used in the identification process. The deployment of DVI teams composed of forensic experts from different fields of expertise and well acquainted with DVI procedures, is essential in events involving multiple casualties that may also include foreign victims. The DVI team should intervene not only in PM examinations but also in the collection of AM data for those individuals not accounted for and by helping police in contacting families of missing people.

Dental Evidence in Forensic Identification - An Overview, Methodology and Present Status

Forensic odontology is primarily concerned with the use of teeth and oral structures for identification in a legal context. Various forensic odontology techniques help in the identification of the human remains in incidents such as terrorists’ attacks, airplane, train and road accidents, fires, mass murders, and natural disasters such as tsunamis, earth quakes and floods, etc. (Disaster Victim Identification-DVI). Dental structures are the hardest and well protected structures in the body. These structures resist decomposition and high temperatures and are among the last ones to disintegrate after death. The principal basis of the dental identification lies in the fact that no two oral cavities are alike and the teeth are unique to an individual. The dental evidence of the deceased recovered from the scene of crime/occurrence is compared with the ante-mortem records for identification. Dental features such as tooth morphology, variations in shape and size, restorations, pathologies, missing tooth, wear patterns, crowding of the teeth, colour and position of the tooth, rotations and other peculiar dental anomalies give every individual a unique identity. In absence of ante-mortem dental records for comparison, the teeth can help in the determination of age, sex, race/ethnicity, habits, occupations, etc. which can give further clues regarding the identity of the individuals. This piece of writing gives an overview of dental evidence, its use in forensic identification and its limitations.

Evaluation of dental expertise with intra-oral peri-apical view radiographs for forensic identification

Background:

Identification of a dead person is important in starting the investigation into the circumstances of death. In the absence of forensic odontologist, it is vital that general dentists are able to compare the ante mortem-post mortem (AM-PM) records and with their ability, correctly interpret the individuality of the person.

Aims:

This study wascarried out to find out the accuracy with which undergraduate, graduate and post-graduate dentists can do this comparison, using the simulated AM-PM intra-oral peri-apical (IOPA) view radiographs.

Setting and Design:

A total of 60 investigators of which 20 undergraduate students, 20 general dentists, 20 post-graduate dentists viewed 10 pairs of simulated AM and PM radiographs and recorded their findings.

Materials and Methods:

Ten pairs of simulated AM-PM IOPA view radiographs were given to 60 dentists to investigate their discriminatory potential for dental identification purposes. The results were statistically analyzed.

Statistical Analysis:

χ² -test and Mann-Whitney U-test were carried out to compare the sensitivity, specificity and accuracy of the three types of examiners (UG, G, PG).

Results:

The results showed sensitivity of 59.8%, specificity of 62.6%, accuracy of 61% for undergraduate students, sensitivity of 86.6%, specificity of 87.5%, accuracy of 87% for graduate doctors, sensitivity of 89.3%, specificity of 92.3% and accuracy of 90.5% for post-graduate doctors respectively.

Conclusion:

Inexperienced investigators in forensic identification showed fairly acceptable results, therefore, introduction of forensic odontology in an undergraduate course may help general dentists to provide better service, if required, in the absence of a forensic odontologist.

Age estimation for forensic purposes in Italy: ethical issues

Age assessment in children and young adults is a relevant medicolegal issue due to the gradual increase of persons devoid of proper identification documents in European countries. Because of the illegal immigration and growing crime rates among children and adolescents, age estimation for forensic purposes is often required. The scientific research and the extensive experience of forensic experts in the last decades focused on the use of radiographic methods addressed to evaluate the degree of skeletal or dental development as the most accurate parameters to estimate the chronological age of children and adolescents. This paper analyzes the ethical issues related to age estimation procedures based on radiographic methods, showing how the ethical principles of beneficence, nonmalevolence, justice, and autonomy may be guaranteed during the execution of the age assessment in forensic practice. The procedure might be conducted in accordance with international guidelines and protocols, though they need a higher homogenization and standardization. A strong collaboration between various scientific societies of professionals (forensic odontologists, forensic pathologists, forensic anthropologist, radiologists, pediatricians, and psychologists), who have been involved in age estimation for years, is needed to reach this goal.

Influence of the examiner's qualification and sources of error during stage determination of the medial clavicular epiphysis by means of computed tomography

Computed tomography (CT) of the medial clavicular epiphysis has been well established in forensic age estimations of living individuals undergoing criminal proceedings. The present study examines the influence of the examiner's qualification on the determination of the clavicular ossification stage. Additionally, the most frequent sources of error made during the stage assessment process should be uncovered. To this end, thin-slice CT scans of 1,420 clavicles were evaluated by one inexperienced and two experienced examiners. The latter did the evaluations in consensus. Two classification systems, a five-stage system and a substaging system for the main stages 2 and 3, were used. Prior to three of his six assessment sessions, the inexperienced examiner was specifically taught staging of clavicles. Comparison of the examiners' results revealed increasing inter- and intraobserver agreements with increasing state of qualification of the inexperienced examiner (from κ= 0.494 to 0.674 and from κ= 0.634 to 0.783, respectively). The attribution of a not-assessable anatomic shape variant to an ossification stage was identified as the most frequent error during stage determination (n= 349), followed by the overlooking of the epiphyseal scar defining stage 4 (n= 144). As to the clavicular substages, classifying substage 3a instead of 3b was found to be the most frequent error (n= 69). The data of this study indicate that κ values must not be considered as objective measures for inter- and intraobserver agreements. Furthermore, a high degree of specific qualification, particularly the knowledge about the diversity of anatomic shape variants, appears to be mandatory and indispensable for reliable evaluation of the medial clavicular epiphysis.

Comparison of the applicability of four odontological methods for age estimation of the 14 years legal threshold in a sample of Italian adolescents

The 14-years age threshold is especially important in Italy for criminal, civil and administrative laws. Several methods relying on dental calcification of the teeth, up to the second molar, are used for the evaluation of age in childhood. The objective of the research was to compare the inter-rater agreement and accuracy of four common methods for the dental age estimation - Demirjian (D), Willems (W), Cameriere (C) and Haavikko (H) - in a sample of Italian adolescents between 11 and 16 years. The sensitivity and specificity, and the different level of probability, according to the peculiarities of Italian criminal and civil law, were compared for the methods examined, considering the threshold of 14 years. The sample was composed of 501 digital OPGs of Italian children (257 females and 244 males), aged from 11 years and 0 days to 15 years and 364 days. The maturation stage of the teeth was evaluated according to D, W, H and C methods by three independent examiners. Mixed statistical models were applied to compare the accuracy and the errors of each method. The inter-rater agreement was high for the four methods and the intraclass correlation coefficients were all ≥ 0.81. Methods H and C showed a general tendency to underestimate the age in the considered sample while the methods D and W tended to overestimate the child's age. In females, D and W were more accurate than C, which is more accurate than H. In the males, W is the most accurate method even though it over-estimated age. Considering the 14-years threshold, the sensitivity of D and W methods is quite high (range 0.80; 0.95) and specificity is low (range 0.61; 0.86). The principal findings of the research are: the W and D methods are much more accurate than C and H, but they tend to overestimate the age. The C method largely underestimates the age (by ~1 year) for both genders and for all operators. H is unsuitable for dental age estimation in the Italian population, while W and D yielded high sensitivity but low specificity, thus producing high rates of false positive results. The choice of method to estimate if an Italian child has reached the 14-years legal threshold should mainly be chosen according to the different legal milieu (if civil or criminal) and the gender of the examined individual. The age assessment in criminal case must be prudently managed.