Premolar maturity index (IPM) for indicating legal age 12 years in a sample of south Indian children - A digital pantomographic study

Legal age of 12 years has been set as the minimum age of criminal responsibility in many countries. This paper concerned a method for predicting the legal age 12 years based on the maturation of lower first and second premolars. The sample consisted of 900 digital pantomographs of south Indian children (450 males, 450 females) aged between 8 and 16 years. Among them, 580 DPTs were used as test sample and 320 DPTs as validation sample. New cut-offs at the age threshold 12 years were determined by using the measurement of open apices in first premolars (IPM1 < 0.10), second premolars (IPM2 < 0.14) and the combined method (IPM1 + IPM2 < 0.12). The sensitivity (Se), specificity (Sp) and posttest probability (PTP) were established. For IPM1 < 0.10, the Se, Sp and PTP were 92.4 %, 91.3 % and 91.1 % for males and 90.8 %, 87 % and 86.5 % for females. For IPM2 < 0.14, they were 92.6 %, 93.6 % and 93.4 % for males and 91.5 %, 83.1 % and 83.4 % for females. And, for the combined predictor (IPM1 + IPM2 < 0.12), these values were 92.6 %, 94.8 % and 94.6 % and 90.5 %, 84.9 % and 84.7 % in males and females respectively. The best score of positive predictive value and specificity was obtained for males with the combined predictor (IPM1 + IPM2 < 0.12) and with single predictor (IPM1 < 0.10) for females. To conclude, the combined predictor has resulted in better discrimination in males, while in females the single predictor (IMP1 < 0.10) did slightly better. Further studies are warranted to test the combination of dental and skeletal indicators for the prediction of 12 years in the studied population.

Forensic odontology and dental age estimation research: a scoping review a decade after the NAS report on strengthening forensic science

Dental age estimation (DAE) is one of the most reliable and useful scientific methods employed by forensic odontology (FO) for human identification. In 2009, the US National Academy of Sciences (NAS) report highlighted the need to deepen research in many disciplines, among which FO received strong criticism for specific expertise. The aim of this review is to provide a comprehensive overview in order to systematically map the latest original research done in FO, as well as identify DAE within this field. A systematic search was performed from 2014 to 2019. In total, 644 studies were identified for qualitative analysis: DAE was the most studied topic (41.30%). Asia was the most productive continent with 58.27% of the global production on DAE; India was the most productive Asian country, with 32.33% and 55.48% of global and Asian production, respectively. The University of Macerata (Italy), KU Leuven (Belgium), University of Split (Croatia), and University of São Paulo (Brazil) led DAE research. Authors from leading countries on DAE research demonstrated great individual productivity, which is evidence of their scientific efforts, but also possible risks if the continuity of this line of research depends on them. Although FO has significantly focused its research on DAE, the absence of publications on controversial topics but necessary for research according to the NAS report shows the possible lack of interest of authors or journals to address them.

Validation of the Italian, European, North German, Malaysian, and South African black formulas on Cameriere method using panoramic radiographs in Kenyan children

This study aimed to validate the accuracy of five different formulas based on the Cameriere method for age estimation in Kenyan children. We analyzed panoramic radiographs of 350 Kenyan children (184 males and 166 females) aged between 6 and 13 years. The dental development of each child was estimated by the analysis of the first seven left permanent teeth in the left mandible. Dental age was calculated by the Italian, European, North German, Malaysian, and South African black formulas previously published in peer-review journals. The children's mean chronological age (CA) was 9.34 ± 2.02 years and 9.26 ± 2.01 years for males and females. In males, the South-African formula overestimated CA least, by 0.12 years, followed by the Italian formula by 0.22 years, the European formula by 0.37 years, the Malaysian formula by 0.48 years, and the North-German formula overestimated the most, by 0.57 years. In females, the South-African formula underestimated CA by - 0.12 years. The Italian overestimated by 0.12 years, followed by the North-German formula by 0.29 years, the European formula by 0.31 years, and the Malaysian formula by 0.40 years. The Italian formula provided the best accuracy in the absolute difference within ± 1 year, by 75.72% and 75%, following the North-German formula by 66.47% and 70.27% for males and females, respectively. Therefore, the findings suggest that the Italian formula best estimates dental age in Kenyan children.

Quantifying the potential of morphological parameters for human dental identification: part 2-selecting the strongest identifiers in mandibular permanent teeth

The current study aimed to select the best dental morphological identifiers for human identification. Sixty-two panoramic radiographs were collected retrospectively, in which six measurements were performed on all seven mandibular left permanent teeth: tooth length (TL), crown length (CL), root length (RL), crown width (CW), cervical width (CEJW), and root width (RW). Nine length-width ratios were then calculated using these measurements. Three groups of statistics were considered: (1) inter-observer reliability quantified by intra-class correlation (ICC); (2) mean "potential set"; and (3) Spearman correlation. A step-by-step cascade was then established based on selected parameters. In a univariate approach, the following parameters were the best identifiers: TL/CW for tooth 36 (ICC 0.82; mean potential set 13.7%), TL/CEJW for tooth 35 (ICC 0.87; mean potential set 15.2%), and TL/RW for tooth 32 (ICC 0.89; mean potential set 16.0%). The correlations between these three parameters ranged from 0.24 to 0.47. In a multivariate approach, the following parameters had the best identifying capacity: all parameters combined for tooth 31 (mean potential set 8.1%), for tooth 35 (mean potential set 11.9%), and for tooth 32 (mean potential set 16.3%). In conclusion, a single ratio in a specific tooth narrows down the potential set of matches, but the mean potential set remains relatively large. Combining all ratios of a single specific tooth increases the certainty of the match. In particular, tooth 31 was the strongest identifier.

Quantifying the potential of morphological parameters for human dental identification: part 3-selecting the strongest skeletal identifiers in the mandible

The current study aimed to select the best mandibular morphological identifiers. One-hundred eighty-five panoramic radiographs were retrospectively collected, in which four landmarks were located on the mandible: the most superior point of the condyle right/left (CONR/L), of the coronoid right/left (CORR/L), of the mandibular lingula right/left (LINR/L), and the most mesial point of the mental foramen right/left (MMFR/L). Five linear measurements, 6 angles, and 10 ratios were measured bilaterally. Three groups of statistics were considered: (1) mean potential set; (2) inter-observer agreement quantified by intra-class correlation (ICC) and within-subject coefficient of variation (WSCV); and (3) Spearman correlation. Parameters were selected for a step-by-step cascade. In a univariate approach, the following parameters proved to have the best identifying capacity: ratio 3 right (between lines CONR - CORR and LINR - MMFR) with mean potential set 13%, ICC 0.90, and WSCV 4.8%; ratio 4 (between lines CONR/L - CORR/L and MMFR - MMFL) with mean potential set 13%, ICC 0.92, and WSCV 8.9%; and angle 4 left (between landmarks LINL, MMFL, and MMFR) with mean potential set of 18%, ICC 0.91, and WSCV 1.2%. The correlation coefficients ranged from 0.01 to 0.33. In a multivariate approach, the identifying capacity improved drastically, with all ratios combined as the strongest identifier (mean potential set 1.29%). In conclusion, a single ratio or a single angle already narrows down the set of potential matches, but the mean potential set remains relatively large. Combining all ratios drastically increases the certainty of the match.

A disaster victim identification workshop focused on forensic odontology using embalmed human remains

A high number of victims of mass casualty incidences are identified through their teeth. While forensic odontologists need to have a complex skillset during a disaster victim identification (DVI) response, hands-on training opportunities are rare. In countries with very limited forensic casework, such as New Zealand, many forensic odontologists find it difficult to achieve the number of annual forensic dental identifications required to maintain their credentialling. This report details the development of a hands-on forensic odontology-focused DVI workshop using human Crosado-embalmed remains. Anonymous participant evaluations, including five-point Likert and open-ended items, were performed in both years the workshop was held. A total of 10 and 17 participants, predominantly dentists, attended the workshop in 2020 and 2021, respectively. Participant feedback was extremely positive. Likert items were statistically similar between participants in both years. Open-ended items revealed positive feedback regarding the use of cadaveric remains, the gained hands-on experience, or the teamwork aspect. Participants who attended the workshop in both years commented on the positive aspect of repetition to cement their skills. As areas of improvement, participants named (for example) time management and the number of portable X-ray devices, leading to changes that were implemented in 2021. Moreover, the participants expressed interest to further their skills on decomposed, burnt, and fragmented human remains, which for ethical reasons has yet to be implemented. The DVI workshop described here, using embalmed human remains, provides an opportunity to add dental identifications toward annual credentialling requirements for forensic odontologists. Participants rated the course to be excellent overall and highly relevant for their role. For future workshops, there is an interest to include further aspects of the DVI response such as fingerprinting or police work as well as remains, which are altered due to natural or physical reasons.

Accuracy of forensic age estimation using cementum annulation and dentin translucency in adult: a systematic review and meta-analysis

Identification of the living and the dead individual is essential in routine forensic dental examinations. Age determination can be of great value in forensic odontology, not only in identifying bodies but also in relation to crime. When subjects have extensive changes that external features provide no information, teeth are often the only means of identification. Several procedures for age-at-death estimation in adults have been introduced. Two of them, cementum annulation and dentin translucency, are frequently used as a single dental indicator. Cementum annulation refers to an alternating dark and light band; each pair of it represents 1 year. Meanwhile, dentin translucency is the other dental physiological process that begins in the second or third decade of life and progresses with age. There are still few studies that compared both methods and their accuracy in estimating adult age at death. Therefore, this study aims to test and compare cementum annulation and dentin translucency accuracy by performing a systematic search on five online databases (Pubmed, Scopus, Ebsco, ScienceDirect, and Wiley). All the research articles must be published in the last 10 years, and the full paper must be available in English. Out of the total 1178 literature, 28 studies were recruited for qualitative analysis and 23 studies for meta-analysis. The results show that dentin translucency age estimation is more accurate than the cementum annulation method in the entire population. It is recommended to use the cementum annulation method for younger adults (15-44 years) and the dentin translucency method for the older ones (≥ 45 years).

Radiographic evaluation of the mandible to predict age and sex in subadults

OBJECTIVE

Forensic examinations involve the identification of age and sex from living or mortal remains. The mandible comprises several growth parameters and is often recovered intact, making it an important tool for radiological identification. Therefore, the present study was conducted to determine the accuracy of various mandibular measurements on digital panoramic images in indicating sex and age in a subadult population. Methods: Panoramic images from 1,100 individuals (550 males, 550 females) ranging in age between 3 and 13 years were divided into 11 groups according to age. Ten mandibular linear dimensions (ramus height, condylar ramus height, coronoid ramus height, maximum ramus breadth, minimum ramus breadth, bigonial breadth, bicondylar breadth, bimental breadth, lateral length of mental foramen, vertical length of mental foramen) and gonial angle were measured bilaterally. Univariate discriminant and regression analyses were performed to determine the most significant predictors of sex and age.

RESULTS

All linear dimensions were higher for males than females for all age groups. Gonial angle did not vary significantly by gender. Discriminant analysis showed linear measurements and gonial angle exhibited poor accuracy in sex determination. Despite a positive correlation between linear measurements and a negative correlation between gonial angle and age, the discriminant analysis found that age estimations made using all the recorded variables had an accuracy of only 66.72%.

CONCLUSION

In line with previous research on different populations, findings for the selected subadult population sample showed that the growing mandible does not present sufficient sexual dimorphism to be useful for sex and age estimations.

[Automated digital superimposition of the 3D model and archival photographs of full removable dentures in forensic dentistry]

THE AIM THE STUDY

The purpose of the work is to perform automated alignment of two-dimensional archival photographs of the first prosthesis and a digital model of the complete removable prosthesis by superposition in order to determine or deny their possible belonging to one user.

MATERIALS END METHODS

The superposition was carried out in the Exocad program (DentalCAD 3.0 Galway) using the standard 2D-3D alignment algorithm of the «SmileDesign» module; in the same program. In addition, Keynote and Fusion 360, and Autodesk programs were used. Statistical measurements were carried out at the statistically significant level of p<0.05.

RESULTS

A comparison of four different-angle and different-scale photographic images of a removable denture of the upper jaw teeth with a three-dimensional copy of the same version of the prosthesis of the life physician of the royal family E.S. Botkin was made. When superimposing a digital three-dimensional model and a two-dimensional photograph of the original prosthesis with marked anthropometric points (n=51), 21 of them coincided or touched each other (41.2%). Another 26 points were located side by side (distance up to 1.5 mm) (50.9%) and 4 did not coincide (distance >1.5 mm, but no more than 3.5-4 mm) (7.8%). When the reference points were combined, the contours, the configuration of the relief and the peripheral boundaries of all three objects mostly coincided. The linear longitudinal and transverse dimensions of the bases of the prostheses also mostly coincided. The exception was the distal border of the bases, and the level of the cutting edges of the anterior artificial teeth, where complete coincidence was not observed, due to differences in the degree of erasability.

CONCLUSION

Comparison of the original prosthesis from Ipatiev's house and its stereolithographic model was a test for the accuracy of the matching method used. The stereotype of the compared images is proved and the consistency of the possibility of computer combination of three-dimensional and two-dimensional objects is confirmed. The use of traditional methods of forensic identification and evaluation of the results by methods of mathematical statistics allowed us to conclude that the two different complete removable dentures of the upper jaw depicted in the photographs belong to one user.

Concordances and correlations between chronological, dental and bone ages: A retrospective study in French individuals

Bone and dental maturations are subject to physiological, environmental and pathological variables and are unique to each individual. Numerous methods for age estimation appeared to answer a new demand explained by the contemporary migratory movements and the increase of the crime rates. The objective of this study was to observe the relationships between skeletal and dental maturation stages to estimate which methods can be applied to a French population. This retrospective study was based on panoramic and cephalometric radiographs belonging to 192 (101 females and 91 males) orthodontic patients aged between 9 and 19 years, inhabitants of the Provence-Alpes-Côte d'Azur region. The Demirjian method based on dental calcification was used to estimate dental age. For the assessment of skeletal maturity and bone age, the Cervical Vertebral Maturation (CVM) method (Baccetti et al.) and its computerized version (Decocq et al.) were used. Spearman's correlation tests were performed to estimate the correlation between dental calcification stages and those of cervical vertebral maturation among the study population. The methods of Lin's concordance correlation coefficient and Bland and Altman were used to analyze the concordance between bone, dental and chronological ages. A moderate but statistically significant correlation was obtained between dental and skeletal developmental stages (R = 0.383-0.618). The tooth showing the highest correlation with vertebral stages was the second molar for both sexes. Earlier vertebral maturation stage affiliation was observed in girls. The results confirmed that bone and dental maturations can be assessed to estimate relevant biological ages for children in orthodontic or forensic contexts.

Forensic Odontological Parameters as Biometric Tool: A Review

Human identification by virtue of dental identification is on the increase in the past few years and has served as a major adjunct in the identification process. The science associated with the dealing of evidences from dental, oral, and paraoral structures—Forensic Odontology, is a boon in itself. It has been seen that the role of forensic odontology has increased as most of the times teeth and other orally associated structures remain the only means of identification in the worst of scenarios where the conventional biometrics such as fingerprint, iris scan, palm print, etc., may be lost and are therefore not reliable enough to resolve the purpose of identification. There are various important aspects in forensic odontology which are associated with the study of tooth prints, i.e., ameloglyphics, radiographs, the study of palatal rugae patterns, i.e., rugoscopy, cheiloscopy, i.e., the study of lip patterns, tongue prints which can serve as an important biometric tool to aid in the human identification process. Dental biometrics helps to determine several parameters that serve in the interest of forensics such as type of specimen, population affinity, sex, age, stature, race, and various other individualization factors. So, comparative dental identifications with the help of a biometric recognition system will play a major role in identifying deceased individuals in disasters, crimes, or any other mass tragedies.

How to cite this article: Kaul B, Vaid V, Gupta S, et al. Forensic Odontological Parameters as Biometric Tool: A Review. Int J Clin Pediatr Dent 2021;14(3):416–419.

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.

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.

Evaluation of the effect of impaction on the mineralization of mandibular third molars and forensic age estimation in a sample of south Indian children

Assessment of third molar mineralization is a basic forensic odontological method available for age estimation in children and adolescents. Due to their protracted development into the late adolescence, their development has become the subject of interest and acquired great forensic importance. It is clearly evident in the literature that impaction factor has an influence on the rate of maturation of the third molars. In this regard, the present study was undertaken to test the relationship between impaction and its concomitant effect on the mineralization of the third molar and forensic age estimation. A total of 520 digital orthopantomograms (OPG) of 260 males and 260 females of south Indian origin were assessed retrospectively. Maturation of the third molars (I3M) was assessed using the method of Cameriere et al. (Int J Leg Med 122 (6):493-497, 2008). Impaction status was determined according to the position of lower right and left third molars in relation to the long axis of the second molars. Out of the total sample, 68.1% of lower left third molars and 71.2% of lower right molars were impacted. Statistical measures for I3M were calculated in the males and females for both impacted and non-impacted third molars. It was ascertained that the mean age and I3M values were higher in impacted third molars, indicating the slower rate of maturation than non-impacted ones. The sensitivity and specificity of the test (I3M < 0.08) was 96.2% and 72.4% for non-impacted third molars and 46.2% and 87% for impacted third molars, respectively. Our findings indicate that the cut-off value of I3M < 0.08 resulted in greater number of age misclassifications (false negatives) for impacted molars, highlighting the need for new cut-off value of I3M to meet the legal standards. It was concluded that the mineralization of impacted third molars was slower compared to non-impacted ones in south Indian males and females. Further studies are warranted to validate these findings among a larger and more diverse sample.

The biasing impact of irrelevant contextual information on forensic odontology radiograph matching decisions

The potential biasing effect of irrelevant context information on the forensic odontology method of radiograph-based identification has never been empirically investigated despite being a recognized problem in other forensic science disciplines. This study examines the effect of irrelevant context information on the probability judgment of match (JOM) of practicing forensic odontologist and dentist participants who were asked to match pairs of dental radiographs supplemented with irrelevant case information. The irrelevant case information contained domain task-irrelevant context information which varied in strength (strong or weak). It suggested either supportive or contradictory bias relative to the actual match status of the radiograph pairs. The dental radiographs consisted of verified match and non-match radiographs pairs sampled and de-identified from actual forensic cases. Changes in accuracy and JOM between supportive and contradictory contexts conditions revealed a contextual bias. Mixed model analysis showed that strong supportive context increased the odds ratio of correct decisions by a factor of 2.4 [1.23, 4.46]; p = 0.0097. Consistent with the biasing effect, the JOM score differences between strong supportive and contradictory irrelevant context information were 1.03 and 0.43 respectively for the non-match and match decisions. The direction of context suggestion (p = 0.0067), the radiograph match status (p = 0.014), and their interactions (p = 0.0061), were all found to impact the participants' decision. The weak context information was not strong enough to have a significant effect on accuracy or JOM scores. This study demonstrates that radiograph match judgment is affected and can be biased by strong irrelevant contextual information.

Age estimation using third molar maturation based on Demirjian's criteria

Dental age estimation is routinely used in human identification, in both the living and the dead. Teeth follow a predictable pattern of eruption and maturation that can be assessed radiographically in the living, allowing experts to estimate an individual's age. Third molars develop much later than the other permanent teeth, and can be used to estimate age of individuals nearing the age of maturity. Ability of third molar maturation when graded using Demirjian's method in ascertaining whether an individual has attained the medicolegal ages of 16 and 18 years has not yet been verified. The present study involved assessing the third molar maturation of 220 individuals of a training set using Demirjian's scoring system, generating regression models to estimate age using the third molar maturity scores, applying these models on a test set of 40 individuals, and calculating the mean difference (MD) and the mean absolute error (MAE) between the chronological and estimated ages of the test set participants. It was observed that the lowest mean difference and mean absolute error was observed for the maturation of the left mandibular third molar (MD = 1.05 years, MAE = 2.09 years). Boxplots generated in the study report that the third molar maturation stages given by Demirjian can identify whether an individual has attained the medicolegally significant ages of 16 and 18 years of age.

Effect of postmortem interval and conditions of teeth on STR based DNA profiling from unidentified dead bodies

Teeth are important exhibits to establish the identity of unidentified dead bodies by DNA profiling. Tooth acts as a cage to protect DNA from harsh environmental conditions. Unidentified bodies are sometimes found many years after death causing loss of valuable soft tissues which can be used for DNA extraction. Skeletal remains and dental evidence provide the best alternative when decomposed or burnt bodies are examined to establish the identity. In this study, the powder-free method was used to extract DNA from ninety-five teeth of unidentified dead bodies across seven years (2014-2020). Intact and broken dental remains were analyzed majorly from decomposed remains. The present study reports successful STR profiles obtained from dental evidence using powder free method. Complete DNA profiles were obtained from intact teeth while damaged teeth either gave partial profiles or no results. This data suggest that intact teeth are excellent samples for DNA profiling from decomposed unidentified dead bodies even with greater post mortem interval. Findings from this study can hence be useful in establishing the identity in forensic and archeological casework.

A systematic review of 3D scanners and computer assisted analyzes of bite marks: searching for improved analysis methods during the Covid-19 pandemic

The global Covid-19 pandemic has forced forensic dentists to improve infection control methods. This search investigated the practical utilization of different 3D scanners to record and to analyze bite marks in the skin- and inanimate objects with this aim in mind. A systematic review of the literature using keywords like "human bite mark", "bite mark analyzes", "3D analyzes", "3D scanning", "forensic odontology", and "forensic dentistry" was performed in three scientific databases: MEDLINEOvid®, Pubmed® and Google Scholar. The initial search yielded 263 full-text articles, of which 15 were considered eligible and current within the last 10 years. 3D scanners and computer-assisted human bite mark analyzes showed potential advantages and can be effectively used in forensic odontology on skin and inanimate objects. These technologies minimize the number of people being exposed to pathogens, simplify the chain of evidence, facilitate immediate information exchange between the team members and enable the virtual presentation of the expert witnesses in a court of law.

Age estimation based on Willems method versus country specific model in Saudi Arabia children and adolescents

BACKGROUND

The aims of this study were to create a method for estimation of dental age in Saudi children and adolescents based on the Willems model developed using the Belgian Caucasian (BC) reference data and to compare the ability of the two models to predict age in Saudi children.

METHODS

Development of the seven lower left permanent mandibular teeth was staged in 1146 panoramic radiographs from healthy Saudi children (605 male, 541 female) without missing permanent teeth and without all permanent teeth fully developed (except third molars). The data were used to validate the Willems BC model and to construct a Saudi Arabian-specific (Willems SA) model. The mean error, mean absolute error, and root mean square error obtained from both validations were compared to quantify the variance in errors in the sample.

RESULTS

The overall mean error for the Willems SA method was 0.023 years (standard deviation, ± 0.55), indicating no systematic underestimation or overestimation of age. For girls, the error using the Willems SA method was significantly lower but still negligible at 0.06 years. A small but statistically significant difference in total mean absolute error (11 days) was found between the Willems BC and Willems SA models when the data were compared independent of sex. The overall mean absolute error for girls was slightly lower for the Willems BC method than for the Willems SA method (1.33 years vs. 1.37 years).

CONCLUSIONS

The difference in ability to predict dental age between the Willems BC and Willems SA methods is very small, indicating that the data from the BC population can be used as a reference in the Saudi population.

Is third molar development affected by third molar impaction or impaction-related parameters?

OBJECTIVE

To evaluate the effect of third molar impaction and impaction-related parameters on third molar development.

MATERIALS AND METHODS

Panoramic radiographs (N=3972) from 473 males and 558 females between 3.2 and 23.5 years old were analysed. Three parameters of impaction were examined: hindering contact between third and adjacent second molar, retromolar space availability (only in lower third molars), and angulation between the third and adjacent second molar. From the separate parameters, a definition for impaction was derived. Third molars' development was staged according to a modified Köhler et al. staging technique. A linear model was used to compare within-stage and overall age, as a function of hindering contact, retromolar space, and impaction. Furthermore, a quadratic function was used to study the correlation between age and angulation.

RESULTS

Significant differences were found in mean age as a function of hindering contact and retromolar space, depending on third molar location and stage. There was a significant relation between angulation and age, depending on the stage, with all third molars evolving to a more upright position (closer to 0°). Mean ages of subjects with impacted third molars were significantly lower in certain third molar stages, but the differences were clinically small (absolute differences ≤0.65 years). Moreover, after correction for stage differences, no significant differences in age could be demonstrated.

CONCLUSIONS

The development of impacted and non-impacted third molars can be considered clinically equal in our study population.

CLINICAL RELEVANCE

There is no distinction required between impacted and non-impacted third molars for dental age estimation.

iDENTIfyme Informative Campaign: Raising Forensic Dental Identification Awareness in the Community

The identification of human remains can be performed visually through families and next-of-kin, but it is not advisable to rely only on visual recognition; instead, it is preferable to conduct a forensic comparison of antemortem and postmortem data for primary identifiers (fingerprints, DNA, and dental data). A dental autopsy is particularly valuable in the identification process of skeletonized, carbonized, saponified, and fragmented human remains. The principal challenge in the identification process is the search and collection of antemortem data. To this end, all dental information held on a missing person can represent a precious source of individualizing information that families should share with the police or investigating agencies after reporting a disappearance.

Assessing the viability of carious lesions in human identification using STR typing

Human teeth have become a prominent source of DNA for human forensic identification as their biological structure is highly resistant to extreme conditions. Previous forensic identification was mainly dependent on the pulp and the other hard tissues of intact teeth. However, there is high likelihood that only carious teeth can be available for forensic analysis. This study aimed to validate the use of the carious part of the teeth for forensic identification and to compare two DNA extraction methods-the operative technique with the cervical cut technique for human identification using STR typing. The reliability of STR markers in carious part of the teeth was evaluated in 120 carious teeth (60 dental pulp and 60 dentinal carious tissues, respectively) with considerable coverage of gender type and age range to avoid false exclusions. The study was performed on genuine data set where samples have been extracted by proficient dentist during the treatment operation and collected for further analysis. Complete DNA was extracted and the corresponding human identification profile was obtained using the GoldenEye™DNA ID system 20A kit. The operative technique showed a conservative approach to the sampling of carious tissues and allowed safe access to collect carious tissues, whereas the cervical cut technique permitted access to the root canals and complete sampling of the pulp tissues. The findings indicated that there was no significant association between the cervical cut and operative cut techniques (p = 0.165). In addition, there was no statistically significant association between the various teeth types and the obtained profiles observed. The operative technique, by drilling holes on the defected surface of carious human teeth and gentle hand excavation of carious tissues, was indicated to be very efficient, preserving, time-saving, and cost-effective in the recovery of human DNA from carious teeth. The result gives new insights that the carious tissues of human carious teeth might be as valid as the healthy teeth for forensic human identification.

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.

Tooth shade variation in Indian population: An objective guide to age estimation

Introduction

The color of the teeth is affected by chronological age due to the variations of the hard and soft tissue structure of the teeth. There are very few studies have assessed the shade of the Enamel and correlated it with the age changes. Hence the study aimed to assess the enamel shade with the aging in the individual.

Materials and methods

The central incisors of 388 individuals (5-78 years) were assessed for tooth color using a VITA 3D master shade guide and the Hue, Value and Chroma were noted. Mean grey values of the teeth were obtained by image manipulation using Image J software and normalized using the values obtained from the 18% contrast grey card. Chi square tests and linear regression analysis is used to find associations with age and tooth shade variations.Results: The teeth had higher score of Hue, Value and Chroma in older individuals. The tooth shade tended to shift towards redder hue with older age group. Simple linear regression analysis showed a significant correlation of age with normalized grey value in association with the shade parameters. (r = 0.717, SEE = 12.322 years)Conclusion: Tooth color changes with age and the mean age in grey values and shade guides can be a useful tool for age estimation.

Effects of high temperature on dental restorative materials for forensic purposes

This study aimed to observe the effects of high temperature on different restorative dental materials by detecting changes in their microstructural and elemental composition. Disk shaped samples (10 mm diameter, 2 mm depth) were prepared from 8 dental materials (compomer, glass carbomer, ormocer, giomer, zinc reinforced glass ionomer (GI), silver-alloy reinforced GI, zirconia reinforced GI, and conventional GI). Scanning electron microscopy/Energy dispersive X-ray spectroscopy (SEM/EDS) was used to characterize sample surface structures and elemental composition. The same samples were also analyzed using X-ray fluorescence (XRF) to determine the trace element content. Each sample was placed in a porcelain furnace and exposed to 900 °C for 30 min. Observations of macroscopic changes in samples after exposure high temperature were recorded. The microstructural changes in sample surfaces after incineration were detected by SEM. The elemental compositions obtained before and after the incineration were compared after repeating the XRF and EDS analyses. Dental materials demonstrated specific macroscopic changes and microstructural deteriorations detected by SEM images after exposure to high temperature. While several changes occurred in the elemental content of materials in terms of amount, the original elemental composition was preserved. The ability to distinguish dental materials by elemental analyses has had an important impact on the identification process.