Evaluation of the radiographic visibility of the root pulp in the lower third molars for the purpose of forensic age estimation in living individuals

Insights into dental age estimation: introducing multiple regression data from a Black South African population on modified gustafson's criteria

Dental Age Estimation (DAE) is an effective instrument of the rule of law for verifying dubious age claims in living individuals. Once tooth development is complete, only degenerative dental characteristics can be used for this purpose. The influence of ethnicity on these degenerative dental characteristics has not been clarified.Degenerative changes were examined using modified Gustafson's criteria including secondary dentin formation, cementum apposition, periodontal recession and attrition using the Olze et al. (2012) staging scales. Orthopantomograms of 1882 black South Africans, consisting of 934 females and 948 males, from 12.00 to 40.96 years of chronological age were utilized. Two independent examiners performed the evaluations, with one of the two evaluating all radiographs twice.The relationship between individual characteristics and chronological age was analyzed using multiple regression analysis with chronological age as the dependent variable. The resulting R2 values ranged from 0.22 to 0.35, and the standard error of estimate were between 6.6 and 7.3 years. The correlation with age was consistently lower for females compared to males. The characteristic of cementum apposition emerged as critical in this population, due to a particularly low correlation with age and observer agreements partly in the "slight" range. The formula's values for the correlation with age were in general below the literature values for other populations. Overall, the limited precision of the age estimation by the formulae presented, especially for females, must be emphasized. The question of whether ethnicity per se exerts an influence on the characteristics in question, or whether the different socio-economic status, which encompasses factors such as nutrition and healthcare, is the determining factor, needs to be assessed in future studies.

Root canal widths of mandibular molars in predicting the legal age threshold 18 years in a sample of juveniles and sub-adults of south-indian origin: an orthopantomographic study

Pursuing a proficient age estimation methodology introducing novel radiographic methods remains an ongoing and demanding aspect of forensic and medicolegal research. In 2017, Roberts GJ et al. (J Forensic Sci 62(2):351-4, 2017) described a new radiographic method, i.e., root canal width (RCW) patterns to assign a subject to above 18-year-age threshold. Since then, few researchers have investigated the validity of this radiographic method in other populations. The present study aimed to test the usefulness of these RCW patterns in predicting 18 years in a sample of South Indian juveniles and sub-adults aged between 16 and 23. Descriptive analysis revealed that pattern-A was initially observed at a minimum age of 16.08 and 16.22 years in males and females. Pattern-B at 16.31 years in males and 16.22 years in females, while pattern-C was initially recorded at 18.73 years in males and 19.01 years in females, respectively. In summary, if an individual, regardless of sex, exhibits a fully-formed (apex closed) mandibular first, second, and third molars and concurrently displays RCW-C, there is a strong likelihood that the person has exceeded the legally relevant age of 18 years. However, due to higher rate of technically unacceptable errors (adults wrongly identified as individuals below 18 years), reliance on this method alone should be restricted, and it is advisable to combine it with other methods.

Radiological assessment of periodontal ligament space visibility on third molars for forensic age assessment - a comparison study of three different staging scales

Various staging scales have been proposed for the assessment of the visibility of the periodontal ligament space of mandibular third molars on dental panoramic radiographs (PANs) for forensic age assessment in living individuals. However, up to now, there has been no systematic comparison between these staging scales available. We directly compared the 2010 staging scale proposed by Olze et al. with the 2017 staging by Lucas et al. and the 2020 staging by Guo et al. in a German study population. We evaluated 233 PANs from 115 females and 118 males aged 20.0 to 40.9 years using three independent examiners, with one examiner conducting two assessments. We examined the correlation between age and stage, as well as the inter- and intra-rater reliabilities. While the point estimates for the correlation coefficient and the reliability measures were lowest for the Guo scale and highest for the Olze scale, confidence intervals showed a large overlap, particularly for the scales of Olze et al. and Lucas et al. The correlation coefficients between stage and age were consistently lower in females than in males across all methods. In summary, we showed that the staging scales of Olze et al. and Lucas et al. were very similar. The Olze method showed higher point estimates across all analyses, and because there are more reference data available for this method, we argue that it should be preferred as the method of choice for further studies in the field. However, Guo method could be considered for instances, in which the inter-radicular periodontal ligament is not evaluable.

Dental age assessment in the living: a comparison of two common stage classifications for assessing radiographic visibility of the root canals in mandibular third molars

After dentition is complete, degenerative tooth characteristics can be used for dental age assessment. Radiological assessment of the visibility of the root canals of the mandibular third molars in dental panoramic radiographs (DPRs) is known to be one such suitable feature. Essentially, two different stage classifications are available for evaluating the visibility of the root canals of mandibular third molars in the DPR. The aim of this study was to determine if one method outperforms the other. Therefore, the 2010 method of Olze et al. was directly compared to the 2017 method of Lucas et al. in the 2020 modification of Al Qattan et al. To this end, 233 DPRs from 116 females and 117 males aged 20.0 to 40.9 years were evaluated by three independent experienced examiners. In addition, one examiner ran two independent evaluations. Correlation between age and stage was investigated, and the inter- and intra-rater reliability was estimated for both methods. Correlation between age and stage was higher with the Olze method (Spearman rho 0.388 [95% CI 0.309, 0.462], males and 0.283 [95% CI 0.216, 0.357], females) than the Lucas method (0.212 [95% CI 0.141, 0.284], males and 0.265 [95% CI 0.193, 0.340], females). The intra-rater repeatability of the Olze method (Krippendorff's α = 0.576 [95% CI 0.508, 0.644], males and α = 0.592 [95% CI 0.523, 0.661], females) was greater than that for the Lucas method (intra-rater α = 0.422 [95% CI 0.382, 0.502], males and α = 0.516 [95% CI 0.523, 0.661], females). Inter-rater reproducibility was also greater for the Olze method (α = 0.542 [95% CI 0.463, 0.620], males and α = 0.533 [95% CI 0.451, 0.615], females) compared to the Lucas method (α = 0.374 [95% CI 0.304, 0.443], males and α = 0.432 [95% CI 0.359, 0.505], females). The method of Olze et al. was found to present marginal advantages to the Lucas et al. method across all examinations and may be a more appropriate method for application in future studies.

Evaluation of radiographic visibility of root pulp in mandibular second molars using cone beam computed tomography images for age estimation

The purpose of this study is to estimate chronological age and determine whether individuals were aged under or over 18 years using root pulp visibility (RPV) in cone-beam computed tomography (CBCT) images. The study included CBCT images of 699 individuals aged between 15 and 75 years. One thousand twenty-three mandibular second molar (2M) teeth were evaluated using Olze's RPV method in four stages. Descriptive statistics of the stages and the relationship between the stages and the chronological age were assessed. The distribution of the stages was analyzed according to the 18-year age threshold. There was a positive correlation between RPV stages and chronological ages in both sexes. For females and males, the mean ages of stage 0, stage 1, and stage 2, for females and males, were found as 27.21, 28.93, and 33.68 years, and 37.69, 40.9, and 44.88 years, respectively. Stage 0 and stage 1 were found both in individuals aged under and over 18 years, and stage 2 and stage 3 were not observed in individuals aged under 18 years. The presence of stage 2 and stage 3 may be an indication that an individual is aged over 18 years according to Olze's RPV age estimation method. For more reliable results, 2M teeth should be examined bilaterally in forensic science.

Forensic Diagnostics of the Skeletal Age in the Living - Backgrounds and Methodology

BACKGROUND

The expert opinions on forensic age diagnostics requested by state institutions are used to show the exceeding of legally relevant age thresholds, especially the completed 18th year of life. According to the recommendations of the Study Group on Forensic Age Diagnostics (AGFAD), this requires - among other things - a determination of skeletal age.

METHOD

Considering recent scientific knowledge, the current conditions and established skeletal age diagnostics methods are presented. Additionally, this review article sheds light on the influence of ethnicity and socioeconomic status, questions regarding indication, as well as alternative and future developments.

RESULTS AND CONCLUSION

In forensic age diagnostics, particularly hand radiography and thin-slice CT of the medial clavicular epiphysis are relevant for determining skeletal age. The Atlas method of Greulich and Pyle (1959) and the clavicular stages by Schmeling et al. (2004) and Kellinghaus et al. (2010) are primarily used for this. This spectrum of methods, which is based on a very solid database, might be supplemented by MRI studies of the knee joint in the near future.

KEY POINTS

· Determining skeletal age is an essential part of forensic age diagnostics commissioned by state authorities and courts.. · Hand radiography and CT of the medial clavicular epiphysis form the core of the spectrum of methods recommended by the Study Group of Forensic Age Diagnostics (AGFAD).. · Since the radiological studies required for forensic age diagnostics are not medically indicated, it must be ensured that the legal basis is specifically named in each case when commissioning expert opinions.. · MRI studies of the knee joint might increase the spectrum of methods in the near future..

CITATION FORMAT

· Wittschieber D, Hahnemann ML, Mentzel H. Forensic Diagnostics of the Skeletal Age in the Living - Backgrounds and Methodology. Fortschr Röntgenstr 2024; 196: 254 - 261.

A systematic overview of dental methods for age assessment in living individuals: from traditional to artificial intelligence-based approaches

Dental radiographies have been used for many decades for estimating the chronological age, with a view to forensic identification, migration flow control, or assessment of dental development, among others. This study aims to analyse the current application of chronological age estimation methods from dental X-ray images in the last 6 years, involving a search for works in the Scopus and PubMed databases. Exclusion criteria were applied to discard off-topic studies and experiments which are not compliant with a minimum quality standard. The studies were grouped according to the applied methodology, the estimation target, and the age cohort used to evaluate the estimation performance. A set of performance metrics was used to ensure good comparability between the different proposed methodologies. A total of 613 unique studies were retrieved, of which 286 were selected according to the inclusion criteria. Notable tendencies to overestimation and underestimation were observed in some manual approaches for numeric age estimation, being especially notable in the case of Demirjian (overestimation) and Cameriere (underestimation). On the other hand, the automatic approaches based on deep learning techniques are scarcer, with only 17 studies published in this regard, but they showed a more balanced behaviour, with no tendency to overestimation or underestimation. From the analysis of the results, it can be concluded that traditional methods have been evaluated in a wide variety of population samples, ensuring good applicability in different ethnicities. On the other hand, fully automated methods were a turning point in terms of performance, cost, and adaptability to new populations.

Evaluation of distal tibial epiphysis and calcaneal epiphysis according to the Vieth method in 3.0 T magnetic resonance images: a pilot study

In forensic medicine practice, age estimation-both in living and deceased individuals-can be requested due to legal requirements. Radiologic methods, such as X-rays, for the estimation of bone age have been discussed, and ethical concerns have been raised. Given these factors, radiologic methods that reduce radiation exposure have gained importance and have become one of the research topics in forensic medicine. In this study, the MR images of the ankles of patients aged between 8 and 25 years, obtained with a 3.0 T MR scanner, were evaluated retrospectively according to the staging method defined by Vieth et al. In the study, the ankle MR images of 201 cases (83 females and 118 males) with sagittal T1-weighted turbo spin echo and T2-weighted short tau inversion recovery sequences were evaluated independently by two observers. According to the results of our study, the intra- and inter-observer agreements are at a very good level for both the distal tibial and calcaneal epiphyses. All the cases detected as stages 2, 3, and 4 in both sexes for both the distal tibial and the calcaneal epiphyses have been determined to be under the age of 18 years. According to the data obtained from our study, we consider that stage 5 for males and stage 6 for both sexes in the distal tibial epiphysis and stage 6 for males in the calcaneal epiphysis can be used to estimate the age of 15 years. As far as we know, our study is the first to evaluate ankle MR images with the method defined by Vieth et al. Further studies should be conducted to evaluate the validity of the procedure.

Age Group Classification of Dental Radiography without Precise Age Information Using Convolutional Neural Networks

Automatic age estimation using panoramic dental radiographic images is an important procedure for forensics and personal oral healthcare. The accuracies of the age estimation have increased recently with the advances in deep neural networks (DNN), but DNN requires large sizes of the labeled dataset which is not always available. This study examined whether a deep neural network is able to estimate tooth ages when precise age information is not given. A deep neural network model was developed and applied to age estimation using an image augmentation technique. A total of 10,023 original images were classified according to age groups (in decades, from the 10s to the 70s). The proposed model was validated using a 10-fold cross-validation technique for precise evaluation, and the accuracies of the predicted tooth ages were calculated by varying the tolerance. The accuracies were 53.846% with a tolerance of ±5 years, 95.121% with ±15 years, and 99.581% with ±25 years, which means the probability for the estimation error to be larger than one age group is 0.419%. The results indicate that artificial intelligence has potential not only in the forensic aspect but also in the clinical aspect of oral care.

[Radiological methods for age diagnostics : Clinical and forensic aspects]

Age diagnostics play an increasing role in radiology. Medical and forensic questions are indications for the application of age diagnostics. In addition to X‑rays of the hand in childhood, panoramic tomography and computed tomography are currently the standard procedures. Alternative modalities without ionizing radiation (sonography, magnetic resonance imaging) have not (yet) been established. The purpose of this article is to present the indications and methods of age diagnostics in the clinical and forensic contexts and to familiarize you with their advantages and disadvantages as well as the possibility of determining the final length.

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.

Root canal width as a mandibular maturity marker at the 18-year threshold in the Maltese population

INTRODUCTION

The determination of age of majority (the 18-year-old threshold) using the popular Demirjian tooth staging method is unreliable, so other maturity markers are required. This study examines whether the ratio of the root canal widths (RCW) of the mandibular first, second and third molars is a useful indicator of age.

METHODS

Nine hundred eighteen dental panoramic radiographs (DPT) were examined and the ratio of the mid-points of the distal roots of the left mandibular first, second and third molars assessed according to the RCW stages as described by Roberts (J Forensic Sci 62:351-354, 2017).

RESULTS

Individuals who had reached stages RCW-A and RCW-B were represented in a wide range of ages spanning the 18-year-old threshold. Individuals who had reached Stage RCW-C were all above the 18-year-old threshold. It was not possible to analyse a large number of DPTs for various reasons.

DISCUSSION

Individuals categorised as stage RCW-C may be deemed to have reached the 18-year-old threshold. These results are consistent with other published studies. Variation in root morphology and in the rate of development of the third molar limits the applicability of this method.

CONCLUSIONS

RCW staging is an accurate method of determining the 18-year-old threshold. Its limited applicability requires the use of substitute markers in a large number of cases.

Three-dimensional verification of the radiographic visibility of the root pulp used for forensic age estimation in mandibular third molars

OBJECTIVES

The aim of this study was to assess the reliability of panoramic radiography (OPG) using age estimation method using cone beam computed tomography (CBCT) verification in the evaluation of radiographic visibility of root pulp (RPV) of mandibular third molars for age estimation.

METHODS

CBCT and OPG images of 429 mandibular third molars from 290 patients were evaluated. RPV of fully mineralized mandibular third molars was evaluated as stages 0, 1, 2, and 3 for both imaging methods. Descriptive statistics were performed separately for stages by age for both genders. The consistency of these scores with chronological age was evaluated for both imaging methods. The reliability of OPG evaluation was also analyzed with CBCT scores.Results Spearman's rho correlation demonstrated a positive correlation between RPV and chronological age for both genders and for OPG and CBCT evaluation. Considering the minimum ages of both imaging methods, all stages were above the age of 18 except for the female group of Stage 2 and all Stage 0. For the comparison of OPG and CBCT RPV Staging scores, the κ score was found to be 0.312 (p < 0.001), indicating a fair agreement.

CONCLUSION

In conclusion, the absence of Stage 3 at age of 18 and under might have a forensic value for RPV age estimation method. Considering the fair agreement in the verification of OPG scores, it is not possible to determine the exact age with the RPV detected in OPG images, the use of CBCT for the RPV evaluation is recommended to available cases.

Chronological Age Assessment Based on the Root Pulp Visibility in Lower Third Molars in a Group of Thai Population: Panoramic Radiographic Study

Background:

Radiographic visibility of the root pulp in lower third molars is one of the reliable methodologies for chronological age estimation.

Objective:

To evaluate the radiographic visibility of the lower third molar root pulp using digital panoramic radiographs of the Thai population, and determine the appropriation of this technique in age assessment, especially at the age of 18 years.

Methods:

A total of 746 digital panoramic radiographs of the Thai population aged from 16 to 26 years were recruited for the present study. The visibility of root pulp of lower third molars with completed root formation was recorded in the four stages. Descriptive statistics were performed for each stage in both males and females.

Results:

The first appearance of stage 0 is 16.71 years in males and 17.00 years in females. The minimum age of stage 1 was found at 17.08 years in males and 17.18 years in females. The beginning of stage 2 was 18.33 years in males and 18.17 years in females. For stage 3, the earliest presence was started at 18.58 years in males and 18.83 years in females.

Conclusion:

The occurrence of stages 2 or 3 in both males and females indicated that the subject is over 18 years of age. Further study on the Thai population should be conducted to confirm the results of the present study.

Zur Anwendbarkeit der dentalen Methode von Roberts et al. aus dem Jahr 2016 zum Nachweis der Vollendung des 18. Lebensjahres lebender Personen

Es sollte die Methode von Roberts et al. aus dem Jahr 2016 zum Nachweis der Vollendung des 18. Lebensjahres überprüft werden.

Dazu wurden 603 Orthopantomogramme (OPG) von 300 Frauen und 303 Männern im Alter von 16,01 bis 25,99 Jahren von 3 Untersuchern ausgewertet, wobei ein Hauptuntersucher alle OPGs zweimal begutachtet hat. Durch die 3 Untersucher wurde eine konsensuale Bestimmung für die Fälle vorgenommen, bei denen mindestens ein Untersucher ein Stadium zugeordnet hatte.

In 31 Fällen (11 Frauen, 20 Männer) konnte konsensuell ein Stadium bestimmt werden. Hauptursache für die Nichtauswertbarkeit war die nicht abgeschlossene Entwicklung des Zahnes 38 [FDI] (30,18 %), gefolgt von Karies, Restaurationen oder anderen Pathologien (20,56 %) und dem Fehlen des Zahnes 38 (19,57 %). Das Stadium „RCW‑C“ konnte bei den Frauen konsensual nicht, die Stadien „RCW‑B“ und „RCW‑C“ konnten bei den Männern nur 4‑mal (3x „RCW-C“, 1x „RCW-B“) bestimmt werden. Der Cohen’s-Kappa-Wert für die Binnenbeobachterübereinstimmung für die 47 Fälle, in denen der Hauptuntersucher in mindestens einem Durchgang ein Stadium zugeordnet hatte, lag im moderaten bzw. guten Bereich (Frauen: 0,44; Männer: 0,62). Der Fleiss’-Kappa-Wert für die Zwischenbeobachterübereinstimmung der 3 Untersucher für die 69 Fälle, bei denen mindestens ein Untersucher ein Stadium zugeordnet hatte, lag im mangelhaften Bereich (Frauen: 0,07; Männer: 0,11), wobei die 95%-Konfidenzintervalle für den Kappa-Wert auch die „0“ einschlossen.

Alle Personen, bei denen ein Stadium zugeordnet wurde, waren über 18 Jahre alt. Aktuell kann eine Anwendung der Methode nicht empfohlen werden. Es wird die Frage aufgeworfen, ob den Stadien eine allgemeingültige Entwicklungsabfolge zu Grunde zu liegt, da bei 30 Fällen der Befund nicht mit den Stadien in Deckung zu bringen war.

Accurate age classification using manual method and deep convolutional neural network based on orthopantomogram images

Age estimation is an important challenge in many fields, including immigrant identification, legal requirements, and clinical treatments. Deep learning techniques have been applied for age estimation recently but lacking performance comparison between manual and machine learning methods based on a large sample of dental orthopantomograms (OPGs). In total, we collected 10,257 orthopantomograms for the study. We derived logistic regression linear models for each legal age threshold (14, 16, and 18 years old) for manual method and developed the end-to-end convolutional neural network (CNN) which classified the dental age directly to compare with the manual method. Both methods are based on left mandibular eight permanent teeth or the third molar separately. Our results show that compared with the manual methods (92.5%, 91.3%, and 91.8% for age thresholds of 14, 16, and 18, respectively), the end-to-end CNN models perform better (95.9%, 95.4%, and 92.3% for age thresholds of 14, 16, and 18, respectively). This work proves that CNN models can surpass humans in age classification, and the features extracted by machines may be different from that defined by human.

Validation of Roberts' method using root canal width patterns as a mandibular maturity marker in determining the 18-year threshold

The South African Bill of Rights and the Children's Act define a 'child' as a person under the age of 18 years. The age of 18 years is therefore significant for legal purposes in South Africa. The third molar is an important indicator in determining the 18-year threshold. Human biological growth markers are accepted indicators of a subject attaining the age of 18 years. A recent study by Roberts et al. suggested that the relative width of the distal root canals (RCW) of the lower left permanent molars (Fédération Dentaire Internationale notation 36, 37 and 38) as visualised on dental panoramic radiographs can be used as such a growth marker. This study aimed to validate this human biological growth marker in both black and white populations living in South Africa according to Roberts' method. The findings of this validation study were in agreement with this method which showed that individuals with Demirjian stage H left molars and category RCW-C were indeed over the 18-year threshold. Important aspects regarding the rationality and application of Roberts' method are discussed. The authors conclude that this method should not be used in isolation but as an adjunct with other age estimation methods.

Dental and Skeletal Imaging in Forensic Age Estimation: Disparities in Current Approaches and the Continuing Search for Optimization

Medical imaging for forensic age estimation in living adolescents and young adults continues to be controversial and a subject of discussion. Because age estimation based on medical imaging is well studied, it is the current gold standard. However, large disparities exist between the centers conducting age estimation, both between and within countries. This review provides an overview of the most common approaches applied in Europe, with case examples illustrating the differences in imaging modalities, in staging of development, and in statistical processing of the age data. Additionally, the review looks toward the future because several European research groups have intensified studies on age estimation, exploring four strategies for optimization: (1) increasing sample sizes of the reference populations, (2) combining single-site information into multifactorial information, (3) avoiding ionizing radiation, and (4) conducting a fully automated analysis.

Evaluation of secondary dentin deposition in lower first molars to indicate a legal age threshold of 14 years using receiver operating characteristic curves

The age threshold of 14 years has become vital in proving legal violations involving children, particularly in cases of suspected child labour, child pornography and the minimum age of criminal responsibility. In recent years, there has been great interest in the evaluation of age in children and sub-adults using analysis of regressive changes in teeth, with a particular focus on age thresholds that are of medico-legal importance. This research aimed to compare the sensitivity and specificity of stages of root pulp visibility by Olze et al. in a sample of South Indian children aged between 12 and 16 years, with an age threshold of 14 years, using receiver operating characteristic curves and the area under the curve (AUC). Among the four stages of root pulp visibility, stage 2 showed the highest AUC in both female and male cohorts. For stage 2, lower sensitivity and higher specificity values were recorded, indicating the possibility of type II errors (i.e. false negatives). In both sexes, stage 2 had a higher AUC (i.e. 0.696 in females and 0.706 in males, respectively). Based on our findings, it can be concluded that this staging method in lower first molars is of limited value in indicating the legal age threshold of 14 years. Future research should validate the proposed approach in a larger sample and consider how to improve predictions in this area.

Examination of the radiographic visibility of the root pulp of the mandibular second molars as an age marker

Forensic odontologists often confront with conceptually simple medicolegal question of whether an individual is a juvenile or an adult. The demand for additional research into extending dental age estimation methods in late adolescence is never the less, especially in those who have passed 15 years and are suspected older than 18 years. The present research investigated the regressive dental characteristic, i.e. radiographic visibility of the root pulp in mandibular second molars for the purpose of age assessment, especially for determining the age over 18 years. Nine hundred thirty-six orthopantomograms comprised of 436 males and 500 females aged from 14 to 22 years were examined. Descriptive statistics were performed for each stage in both sexes. The correlation statistics revealed that there is a strong, positive correlation between the chronological age and root pulp visibility stages. The analysis revealed that stage 0 occurred first at the age of 14 years in both sexes. Stage 1 first occurred at the age of 14.26 years in females and 14.74 years in males. Stage 2 was first achieved at the age of 18.6 and 15.2 years in males and females, respectively. The suitability of the studied characteristics in mandibular second molars for age estimation could be confirmed but of limited value. The presence of this stage 2 root pulp visibility in male subjects represents a potential criterion for indicating the age over 18 years. In future studies, the pattern of secondary dentin formation in other tooth types should be investigated.

Preliminary analysis testing the accuracy of radiographic visibility of root pulp in the mandibular first molars as a maturity marker at age threshold of 18 years

Forensic age estimation, after completion of third molar mineralization, regressive features such as apposition of secondary dentin, which is seen as narrowing of the pulp space in the radiographs, can be used as an alternative. In the present study, we explored the radiographic visibility of the root pulp of mandibular first molars using stage classification of Olze et al. (Int J Legal Med 124(3):183-186, 2010) in a sample of 901 orthopantomograms (404 males and 497 females) of south Indian origin with age ranging from 14 to 22 years. Descriptive statistics for the stages according to age was performed for both sexes separately. The strength and direction of the relationship between the chronological age and pulp visualization stages was tested using spearman's rho correlation statistics. The relationship between age and stage attainment showed statistical significance for both sexes. A strong, positive correlation was seen between the stage and chronological age. All males and females presenting stage 0 of root pulp visibility were younger than 18 years. If stage 1 is determined, it is highly possible that an individual regardless of sex is younger than 18 years. Stage 2 was attained in 79.6% males and 83.1% females who were at least 18 years. One hundred percent males and 92.8% females with stage 3 were at least 18 years. The accuracy of this method in mandibular first molars for estimating age threshold of 18 years ranged from moderate to high. However, it is recommended to use this method in conjunction with other age estimation methods.

Olze et al. stages of radiographic visibility of root pulp and cameriere's third molar maturity index to estimate legal adult age in Hyderabad population

Context:

Predicting one's attainment of age of majority is a controversial issue and considered as important aspect in medicolegal cases. In India, individuals older than 18 years of age have full capacity regarding civil conduct and are tried as adults for criminal charges.

Aims and Objective:

To compare the accuracy of Olze et al., stages of radiographic visibility of root pulp, and Cameriere's third molar maturity index (I_3M < 0.08) to estimate the age of majority.

Materials and Methods:

A total of 615 digital orthopantomographs of children aged between 15 and 22 years. The lower left third molars were evaluated using ImageJ computer software. The effectiveness of both methods was evaluated using sensitivity, specificity, positive likelihood ratios (LR+), and LR negative (LR−).

Results:

For I_3M < 0.08, the sensitivity, specificity, LR+, LR− were 0.76, 0.72, 2.79, 0.32 and 0.67, 0.76, 2.83, 0.43 in males and females respectively. For Stage 0, the sensitivity, specificity, LR+, LR− were 0.68, 0.86, 5.18, 0.36 and 0.72, 0.91, 8.63, 0.31, respectively.

Conclusion:

Stage 0 of Olze's radiographic root pulp visibility showed to be more accurate than cutoff value of I_3M< 0.08 in discriminating adults and minors of Hyderabad sample when a test of high sensitivity and specificity is required.

Validation of the third molar maturity index cut-off value of <0.08 for indicating legal age of 18 years in Eastern Chinese region

Having a reliable, inexpensive and simple method to estimate 18 years of age would be of help in the forensic field. This study aimed to test the accuracy of the third molar maturity index (I_3M) in indicating the legal adult age of 18 years. This retrospective cross-sectional study analysed 450 digital panoramic images of Eastern Chinese children and young adults (226 females and 224 males) aged between 14 and 22 years. A cut-off value of I_3M < 0.08 was tested in discriminating adults from minors for both sex. For females, the sensitivity of the test (Se) was 75.0%, with a 95% confidence interval (95%CI) of 67.5% to 82.5%. The specificity of the test (Sp) was 100%. The proportion accurately classified (Ac) individuals was 85.8% (95%CI, 81.3% to 90.4%). The Bayes post-test probability was 100% (93.6% to 100%). For males, Se, Sp and Ac were 91.9% (95%CI, 87.1% to 96.7%), 92.0%(95%CI, 86.7% to 97.3%) and 92% (95%CI, 88.4% to 95.5%), respectively. The Bayes post-test probabilities was 92% (95%CI, 88.4% to 95.5%). Males were ahead in the development of third molars comparing to females according to I_3M. A stepwise logistic regression analysis showed that both I_3M and sex contribute to the regression model to discriminate adults (≥18 years) from minors (<18 years), while a receiver operating curve (ROC) analysis indicated some better accuracy of I_3M < 0.12 in females, without statistically significant difference when compared to I_3M < 0.08. The results of this study show that the cut-off value of I_3M < 0.08 may help to discriminate Eastern Chinese adults from minors. However, further study should evaluate the usefulness and possible variability of I_3M cut-off value in a specific population before used for legal and forensic procedures.

Usability of dental pulp visibility and tooth coronal index in digital panoramic radiography in age estimation in the forensic medicine

Age estimation has a great importance due to legal requirements. The aim of our study was to determine the applicability of two different methods in age estimation; one of them based on the calculation of the visibility of the root pulp of mandibular third molar teeth and the other based on the calculation of the tooth coronal index (TCI) in the mandibular first and second molar teeth in the 9059 digital orthopantomogram of people aged between 15 and 40 in Bursa. In the first method in which the visibility of the fully mineralized root pulp of the mandibular third molar teeth was evaluated in 4 stages; the stages 0, 1, 2, and 3 were observed regardless of sex at the earliest 17.2; 19.1; 20.1, and 25.1 years, respectively. In the second method in which TCI was regressed on chronological age using measuring crown and coronal pulp cavity heights, the most accurate age estimation model based on simple linear regression for all cases without any sex difference was found to be with right first molar tooth (SEE ±7304 years) and the most accurate age model based on multiple regression model was found to be with bilateral first molar teeth (SEE ±7413 years). In conclusion, we believe that the root pulp visibility of the third molar teeth can be applied safely for stages 1, 2, and 3 at 16, 17, and 21 years of ages, respectively. A correlation was also found between TCI and age, and our findings have shown that both methods are available for forensic purposes.

Dental age estimation based on the radiographic visibility of the periodontal ligament in the lower third molars: application of a new stage classification

The purpose of the present study was to test whether a new stage classification based on radiographic visibility of the periodontal ligament in lower third molars in a Chinese population can be used for the 18- and 21-year thresholds. A total of 1300 orthopantomograms, including equal numbers of northern Chinese males and females evenly distributed between the ages of 15 and 40 years, were analyzed. The stages were defined according to the visibility of periodontal ligament for the outer parts of lower third molar roots because the visibility status of the periodontal ligament between the roots of lower third molars is none valuable in many Chinese individuals. Stage 0 was first achieved at the age of 17.05 years in males and 17.46 years in females. The earliest appearance of stage 1 was 17.47 years in males and 17.86 years in females. Stage 2 was first observed in males at the age of 21.43 years and in females at the age of 21.96 years. The onset of stage 3 was first observed at the age of 25.83 years in males and 23.14 years in females. Compared with the stage classification of Olze et al., which also considers the mesial parts of the roots, the number of assessable cases could be significantly increased. Therefore, our novel approach is effective for age estimation in the Chinese population.

Examination of regressive features of third molars for the purpose of age assessment in the living by means of rescaled regression analyses

The main criterion of dental age assessment in living adolescents and young adults is the evaluation of third molars' mineralization. Concerning forensic age assessment after the completion of third molars' mineralization, apposition of secondary dentine and narrowing of the periodontal membrane as seen as decreasing radiolucent areas in the radiographs for mandibular third molars have already been described as regressive features. The present study examines the combination of both these features for the purpose of age assessment in regression analyses after rescaling the data to make it on the interval scale. To this end, a total of 1245 orthopantomograms was evaluated, taken from 606 females and 639 males in the age group of 15-40 years. The apposition of secondary dentine and narrowing of the periodontal membrane as seen as decreasing radiolucent areas in the radiographs were determined for the lower third molars. The correlation of the features with the chronological age was assessed by means of rescaled regression analyses. Furthermore, regression formulas for age assessment were established. The values of the standard error of estimate ranged between 3.55 and 4.52 years. In general, the rescaled regression of the examined features appears to be suited for forensic age assessment. A limitation of the present study is the comparatively low number of evaluable teeth in the examined age group. Due to an incomplete development or a lack of the mandibular third molars, only a mere half of the respective teeth could be included in the statistical analysis.

Age assessment in the living using modified Gustafson's criteria in a northern Chinese population

Regressive dental changes appear to be suitable for age assessment in living adults. In 2012, Olze et al. showed that several criteria presented by Gustafson for extracted teeth can also be applied to orthopantomograms. The objective of this study was to test the applicability and reliability of this method in a Chinese population. For this purpose, 1300 orthopantomograms of 650 female and 650 male Chinese aged between 15 and 40 years were evaluated. The characteristics of secondary dentin formation, periodontal recession, attrition, and cementum apposition were reviewed in all the mandibular premolars. The sample was split into a training and test dataset. Based on the training set, the correlation of the individual characteristics with chronological age was studied with a stepwise multiple regression analysis, in which individual characteristics formed the independent variable. According to the results, the R values amounted to 0.80 to 0.83; the standard error of estimate was 4.29 to 4.75 years. By analyzing the test dataset, the accuracy of the present study, Olze's and Timme's formulas were determined by the difference between the estimated dental age (DA) and chronological age (CA). Taking both mean differences and mean absolute differences into account, the Chinese age estimation formula did not always perform better compared with Olze's and Timme's formulas for both males and females. It was concluded that this method can be used in Chinese individuals for age assessment. However, the applicability of the method is limited by the quality of the X-ray images, and the method should only be applied by experienced forensic odontologists.

CT and MR imaging used in age estimation: a systematic review

Computer Tomography (CT) and Magnetic Resonance Imaging (MRI) may be useful tools in assessment of age of an individual. This article presents a review of published studies using CT or MRI in dental age estimation. They were published between July 2004 and September 2017 investigating different types of teeth, methods and formulae for age estimation. Twenty-seven articles were included. The different studies show good results, and it seems that a combination of different types of teeth, methods (depending on the degree of root formation) and cooperation between different disciplines in the same study gives a higher accuracy.

Studies on the radiographic visibility of the periodontal ligament in lower third molars: can the Olze method be used in the Chinese population?

The purpose of the present research is to study the radiographic visibility of the periodontal ligament in third molars from a northern Chinese population to determine if this methodology could be used for the 18-year threshold. A total of 1300 conventional orthopantomograms from 650 males and 650 females of northern Chinese subjects aged between 15 and 40 years were analyzed. The radiographic visibility of the periodontal membrane of fully mineralized third molars was assessed using the stages described by Olze et al. (2010). Stage 0 first appeared at the age of 17.05 years in males and at the age of 18.76 years in females. Stage 1 was first detected at 18.52 years in males and 19.59 years in females. Stage 2 was first achieved by males at the age of 22.33 years and by females at the age of 21.37 years. The earliest appearance of stage 3 was 26.85 years in males and 24.92 years in females. If stage 1 is determined, it is possible to prove that an individual has already attained the age of 18 years. Stages 2 and 3 can be used to determine that a person is over 21 years of age. However, it should also be noted that in 271 cases of tooth 38 and 255 cases of tooth 48, the visibility stage could not be reliably assessed because of fused roots or narrowed furcations. Therefore, this method seems to be of limited value for age estimation in the Chinese population.

The role of forensic medicine and forensic dentistry in estimating the chronological age of living individuals in Hamburg, Germany

Age estimation represents one of the primary responsibilities of forensic medicine and forensic dentistry. It is an integral procedure aiming to estimate the chronological age of an individual, whose age is either unknown or doubtful, by means of assessing the stage of dental, skeletal, and physical development. The present publication reviews the methods and procedures used in estimating the age of young living individuals as well as the experiences of the Institute of Legal Medicine in Hamburg-Eppendorf, Germany, during the last 25 years. From 1990 to 2015, 4223 age estimations were carried out in Hamburg. During this time, forensic age estimation was requested by different concerned authorities including courts, the foreigners' registration office (Zentrale Ausländerbehörde), and the state office of education and consultation (Landesbetrieb Erziehung und Beratung). In the context of judicial proceedings, orthopantomograms, as well as X-ray examinations of both the left hand and the medial clavicular epiphyses were carried out in accordance with AGFAD recommendations. For investigations not associated with judicial proceedings, orthopantomogram examinations play a key role in the process of age estimation, due to their high diagnostic value and low radiation exposure. Since 2009, mainly unaccompanied young refugees were examined for age estimation. Orthopantomograms and clinical-physical examinations have been used as essential steps in this context to determine whether an individual is 18 years or less. Additional X-ray examinations of the left hand and the medial clavicular epiphyses have been used less frequently.

Evaluation of the ossification of the medial clavicle according to the Kellinghaus substage system in identifying the 18-year-old age limit in the estimation of forensic age-is it necessary?

The evaluation of the ossification of the medial clavicular epiphysis being part of an assigned expert approach according to standard plays an important role within civil and criminal proceedings in assessing whether a person has reached her/his 19th or 22nd year of age. Evaluation of the medial clavicular epiphysis with thin-section CT is one of the methods recommended by the Study Group on Forensic Age Diagnostics of the German Association of Forensic Medicine. In this retrospective study, we evaluated the thin-section CT (section thickness of 0.6 and 1 mm) images of 254 patients (146 male, 108 female) with an age range of 13-28 years according to the Kellinghaus substage system. The mean values of female patients were observed to be about 10 months lower for stage 2a than the mean values of the male patients, about 13 months lower for stage 2b, and about 18 months lower for stage 2c. The earliest appearance for stage 3c was at 19 years in both sexes. Our data from this study were consistent with both our previous studies and the data of other studies. We think that stage 3c is important in determining whether a person has reached the age of 18 or not and, therefore, that the Kellinghaus substage system is a requirement in the assessment of forensic age.

Predictive values derived from lower wisdom teeth developmental stages on orthopantomograms to calculate the chronological age in adolescence and young adults as a prerequisite to obtain age-adjusted informed patient consent prior to elective surgical procedures in young patients with incomplete or mismatched personal data

Introduction: Surgical procedures require informed patient consent, which is mandatory prior to any procedure. These requirements apply in particular to elective surgical procedures. The communication with the patient about the procedure has to be comprehensive and based on mutual understanding. Furthermore, the informed consent has to take into account whether a patient is of legal age. As a result of large-scale migration, there are eventually patients planned for medical procedures, whose chronological age can't be assessed reliably by physical inspection alone. Age determination based on assessing wisdom tooth development stages can be used to help determining whether individuals involved in medical procedures are of legal age, i.e., responsible and accountable. At present, the assessment of wisdom tooth developmental stages barely allows a crude estimate of an individual's age. This study explores possibilities for more precise predictions of the age of individuals with emphasis on the legal age threshold of 18 years. Material and Methods: 1,900 dental orthopantomograms (female 938, male 962, age: 15-24 years), taken between the years 2000 and 2013 for diagnosis and treatment of diseases of the jaws, were evaluated. 1,895 orthopantomograms (female 935, male 960) of 1,804 patients (female 872, male 932) met the inclusion criteria. The archives of the Department of Diagnostic Radiology in Dentistry, University Medical Center Hamburg-Eppendorf, and of an oral and maxillofacial office in Rostock, Germany, were used to collect a sufficient number of radiographs. An effort was made to achieve almost equal distribution of age categories in this study group; 'age' was given on a particular day. The radiological criteria of lower third molar investigation were: presence and extension of periodontal space, alveolar bone loss, emergence of tooth, and stage of tooth mineralization (according to Demirjian). Univariate and multivariate general linear models were calculated. Using hierarchical multivariate analyses a formula was derived quantifying the development of the four parameters of wisdom tooth over time. This model took repeated measurements of the same persons into account and is only applicable when a person is assessed a second time. The second approach investigates a linear regression model in order to predict the age. In a third approach, a classification and regression tree (CART) was developed to derive cut-off values for the four parameters, resulting in a classification with estimates for sensitivity and specificity. Results: No statistically significant differences were found between parameters related to wisdom tooth localization (right or left side). In univariate analyses being of legal age was associated with consecutive stages of wisdom tooth development, the obliteration of the periodontal space, and tooth emergence, as well with alveolar bone loss; no association was found with tooth mineralization. Multivariate models without repeated measurements revealed imprecise estimates because of the unknown individual-related variability. The precision of these models is thus not very good, although it improves with advancing age. When calculating a CART-analysis and a receiver operating characteristics - area under the curve of 78% was achieved; when maximizing both specificity and sensitivity, a Youden's index of 47% was achieved (with 73% specificity and 74% sensitivity). Discussion: This study provides a basis to help determine whether a person is 18 years or older in individuals who are assumed to be between 15 and 24 years old. From repeated measurements, we found a linear effect of age on the four parameters in the individuals. However, this information can't be used for prognosis, because of the large intra-individual variability. Thus, although the development of the four parameters can be estimated over time, a direct conclusion with regard to age can't be drawn from the parameters without previous biographic information about a person. While a single parameter is of limited value for calculating the target age of 18 years, combining several findings, that can be determined on a standard radiography, may potentially be a more reliable diagnostic tool for estimating the target age in both sexes. However, a high degree of precision can't be achieved. The reason for persistent uncertainty lies in the wide chronological range of wisdom tooth development, which stretches from well below to above the 18th life year. The regression approach thus seems not optimal. Although sensitivity and specificity of the CART-model are moderately high, this model is still not reliable as a diagnostic tool. Our findings could have impact, e.g. on elective surgeries for young individuals with unknown biography. However, these results cannot replace social engagement, in particular thorough physical examination of patients and careful registration of their histories. Further studies on the use of this calculation method in different ethnic groups would be desirable.

Dental Age Estimation: Pattern Recognition of Root Canal Widths of Mandibular Molars. A Novel Mandibular Maturity Marker at the 18-Year Threshold

The final stage of third molar development is used to assign a subject to above the 18-year threshold. Some subjects exhibiting this final stage are less than 18 years. Radiographs from 1000 females and 1000 males age 16.00-25.99 years were examined. Each half-year age band comprised 50 females and 50 males. Three categories of root canal widths (RCW) of the LL6, LL7, and LL8 [FDI 36, 37, and 38] were defined. Reproducibility was achieved by re-assessing the same subjects 12 months apart. For females, the minimum value for RCW-A was 16.33 years, RCW-B 17.23 years, and RCW-C 18.45 years. For males, the minimum values were RCW-A 17.16 years, RCW-B 18.29 years, and RCW-C 18.16 years. The presence of RCW-C in a female, and the presence of RCW-B or RCW-C in a male is compelling evidence that the subject is above the 18-year threshold.

Dental Age Estimation: A Test of the Reliability of Correctly Identifying a Subject Over 18 Years of Age Using the Gold Standard of Chronological Age as the Comparator

This study was designed to test the reliability of using the third molars to demarcate between child and adult status. A total of 2000 dental panoramic tomographs were used for assessment of the calculated age using the 8-stage system of tooth development and applied to all four third molars. The LL8 was also assessed using this 8-stage system. For each tooth development stage, the Normal distribution and percentile summary data were estimated. The calculated dental age compared with the chronological age was statistically significantly different (p < 0.001) for both females and males giving underestimates of the true age. Comparison of single tooth dental age and chronological age was only slightly different. The most important finding is that the assignment to above or below the 18-year threshold, in the age range 17 years to 19 years, could be wrong on up to 50% of occasions.

Dental age estimation in living individuals using 3.0 T MRI of lower third molars

In order to increase the validity of age estimation in adolescents and young adults when there is no legitimation for X-ray examinations, it seems desirable to be able to assess the mineralization of third molars using X-ray-free imaging procedures. In the present study, the mineralization stages of lower third molars were determined prospectively in 269 male and 248 female individuals aged 12 to 24 years using 3.0 T MRI. The classification system of Demirjian et al. was used to determine the stages. This study presents the minima and maxima, means and standard deviations, median values, and lower and upper quartiles separately for both sexes, for the mineralization stages B-H. Statistically significant sex differences were observed for the mineralization stages C, E, F, and G, and a faster developmental rate was observed for males. It was concluded that magnetic resonance imaging is an X-ray-free alternative to orthopantomography when assessing mineralization of third molars.

Age estimation from canine volumes

Techniques for estimation of biological age are constantly evolving and are finding daily application in the forensic radiology field in cases concerning the estimation of the chronological age of a corpse in order to reconstruct the biological profile, or of a living subject, for example in cases of immigration of people without identity papers from a civil registry. The deposition of teeth secondary dentine and consequent decrease of pulp chamber in size are well known as aging phenomena, and they have been applied to the forensic context by the development of age estimation procedures, such as Kvaal-Solheim and Cameriere methods. The present study takes into consideration canines pulp chamber volume related to the entire teeth volume, with the aim of proposing new regression formulae for age estimation using 91 cone beam computerized scans and a freeware open-source software, in order to permit affordable reproducibility of volumes calculation.