Validation of third molar maturity index (I 3M ) for discrimination of juvenile/adult status in South Indian population

Applicability of Cameriere's third molar maturity index on orthopantomograms and computed tomography scans from a French population

Cameriere developed a method on orthopantomograms (OPG) to assess adult age of 18 years based on the relationship between age and the third molar maturity index I3M. The aim of this study was to evaluate whether Cameriere's method could be applied to computed-tomography scans (CT-scans) from a population of French juveniles and young adults and compare the results obtained from OPG of the same individuals. Our sample comprised 200 examinations that had been performed at the radiological department of a French University hospital between 2007 and 2020. Each patient had received an OPG and a cranial CT scan for medical purposes, and we used a similar adaptation of I3M based on OPG to determine the I3M based on CT scans. Due to exclusion criteria, our final sample comprised 71 OPGs and 63 CT scans. Based on the 71 OPGs, there was concordance between chronological age and estimated age, with a sensitivity of 78.57%, a specificity of 89.47%, and a misclassified rate of 18.03% based on tooth 38, and a sensitivity of 78.79%, a specificity of 91.67%, and a misclassified rate of 17.78% based on tooth 48. Our results based on CT scans presented concordance between chronological age and estimated age for tooth 38 described by a sensitivity of 77.78%, a specificity of 94.12%, and a misclassified rate of 16.98%. The concordance between chronological age and estimated age based on 48 had a sensitivity of 75.00%, a specificity of 93.75%, and a misclassified rate of 19.23%. The > 90% ICC indicate an excellent similarity between measurements of teeth 38 and 48 based on OPGs and CT scans. This study has revealed the applicability of the Cameriere's method to calculate the I3M based on CT scans from a French population. The results based on CT scans are similar to results based on OPGs from the same individuals.

Evaluation of Third Molar Maturity Index by Cone Beam Computed Tomography in Legal Age Estimation: A Preliminary Study

ABSTRACT

This retrospective study aimed to evaluate the accuracy and applicability of the third molar maturity index (I 3M ) for discriminating Turkish minors from adults, and its relationship with chronological age using cone beam computed tomography (CBCT). A total of 122 CBCT scans of Turkish individuals (55 boys and 67 girls) aged 13 to 23 years were evaluated using the I 3M cutoff value. Chronological age gradually decreased as the I 3M value increased. The overall accuracy was 95.9%. The sensitivity and specificity of this test were 93.5% and 97.4%, respectively. Positive predictive value was 95.6%. The intraclass correlation coefficient values of the I 3M for the intraobserver and interobserver agreements were 0.998 and 0.996, respectively. This study showed relatively higher reproducibility of measurements on CBCT scans than on panoramic radiographs in the literature. Cone beam computed tomography may be advantageous and preferred over panoramic radiographs in distinguishing the legal age threshold of 18 years according to Cameriere's method when a more extensive investigation is needed to support the solution of challenging and uncertain cases in forensic medicine.

Third molar maturity index (I3M) assessment according to different geographical zones: a large multi-ethnic study sample

Identification of living undocumented individuals highlights the need for accurate, precise, and reproducible age estimation methods, especially in those cases involving minors. However, when their country of origin is unknown, or it can be only roughly estimated, it is extremely difficult to apply assessment policies, procedures, and practices that are accurate and child-sensitive. The main aim of this research is to optimize the correct classification of adults and minors by establishing new cut-off values for four different continents (Africa, America, Asia, and Europe). For this purpose, a vast sample of 10,701 orthopantomographs (OPTs) from four continents was evaluated. For determination and subsequent validation of the new third molar maturity index (I_3M) cut-off values by world regions, a cross-validation by holdout method was used and contingency tables (confusion matrices) were generated. The lower third molar maturity indexes, from both left and right side (I_3ML and I_3MR) and the combination of both sides (I_3ML_I_3MR) were calculated. The new cut-off values, that aim to differentiate between a minor and an adult, with more than 74.00% accuracy for all populations were as follows (I_3ML; I_3MR; I_3ML_I_3MR, respectively): Africa = (0.10; 0.10; 0.10), America = (0.10; 0.09; 0.09), Asia = (0.15; 0.17; 0.14), and Europe = (0.09; 0.09; 0.09). The higher sensitivity (Se) was detected for the I_3ML for male African people (91%) and the higher specificity (Sp) of all the parameters (I_3ML; I_3MR; I_3ML_I_3MR) for Europeans both male and female (> 91%). The original cut-off value (0.08) is still useful, especially in discriminating individuals younger than 18 years old which is the goal of the forensic methods used for justice.

Use of third molar eruption based on Gambier's criteria in assessing dental age

The biological aspects of determining the dental age of subadults represent an important interdisciplinary scientific link with applications in criminal law and in forensic anthropology and dentistry. In criminal procedural law, it is necessary to determine the exact age of an undocumented person in view of the application of the provisions on juvenile offenders and minor victims. Chronological age can be estimated from the development of the third molars, as these are the only teeth that develop at the age of 18. The aim of this study was to verify the applicability of the Gambier method based on the eruption of the third permanent molars in the mandible and maxilla, to contribute to forensic age assessment. The analyzed group that met the criteria consisted of 811 orthopantomograms (OPGs) (339 females and 472 males) between the ages of 13 and 25 years. The OPGs were retrospectively analyzed according to the method of Gambier et al. (Int J Legal Med 133:625-632, 29), which refers to the eruption stages of the third molar. Differences between eruption stages of maxillary and mandibular third molars were statistically significant in both biological sexes. Intersexual differences in mean age were significant only at stage 3 for any M3 tooth and at stage 1 for mandibular M3. There were no statistically significant differences between the left and right mandibular and maxillary third molars, respectively. Differences between mandibular and maxillary M3 were significant only for stage 1 in males on the left side and for stage 2 in both sexes and sides. The method used allowed the best classification of individuals into minor and adult groups (based on phase D-90.41% of individuals, based on the third stage of the mandibular left third molar-86.29%). Based on the results obtained, we can assume that the method cannot be used alone in the initial examination of living individuals, since all four third molars must be assessed and there are no additional findings from practice.

Correlation of chronological age with dental age estimated using modified Cameriere’s method and UT-age estimation software — a cross-sectional study

Background

Estimating age is essential in both the analysis of human skeletal remains and assessing live persons. The third molar develops over a longer period and is hence used in age estimation for subadults. Since dental age correlates with chronological age better than other growth markers, this study aims to assess the reliability of dental age assessed using the University of Texas (UT) age estimation method and modified Cameriere’s method.

Methods

It is a retrospective cross-sectional study in which the development and maturation of mandibular third molars were examined in 600 orthopantomograms (264 males and 336 females) of South Indian individuals (16–23 years). Dental age was estimated by using an Indian-specific formula based on maturity index value and the UT-age estimation  software program. The results were evaluated using the Student’s t-test for both methods and Pearson’s correlation test to compare chronological age with estimated dental age.

Results

Positive correlation was noted between chronological age and estimated dental age for males, females, and the total sample with highly statistically significant differences (p = 0.000). Modified Cameriere’s method underestimated dental age in samples ranging from less than 1 year to more than 2 years. UT-age estimation method underestimated age in samples above 20 years and overestimated age in samples below 20 years. The predictive classification of utilizing the maturity index was 79.17% accurate.

Conclusions

Dental age was negligibly over and underestimated in UT software method whereas it was overestimated in the modified Cameriere's method. To evaluate the reliability of these two methods, studies with larger sample sizes and population-specific data sets should be performed.

Graphical Abstract

Validity of age estimation methods and reproducibility of bone/dental maturity indices for chronological age estimation: a systematic review and meta-analysis of validation studies

Several approaches have been developed to estimate age, an important aspect of forensics and orthodontics, using different measures and radiological examinations. Here, through meta-analysis, we determined the validity of age estimation methods and reproducibility of bone/dental maturity indices used for age estimation. The PubMed and Google Scholar databases were searched to December 31, 2021 for human cross-sectional studies meeting pre-defined PICOS criteria that simultaneously assessed the reproducibility and validity. Meta-estimates of validity (mean error: estimated age-chronological age) and intra- and inter-observer reproducibility (Cohen’s kappa, intraclass correlation coefficient) and their predictive intervals (PI) were calculated using mixed-effect models when heterogeneity was high (I² > 50%). The literature search identified 433 studies, and 23 met the inclusion criteria. The mean error meta-estimate (mixed effects model) was 0.08 years (95% CI − 0.12; 0.29) in males and 0.09 (95% CI − 0.12; 0.30) in females. The PI of each method spanned zero; of nine reported estimation methods, Cameriere’s had the smallest (− 0.82; 0.47) and Haavikko’s the largest (− 7.24; 4.57) PI. The reproducibility meta-estimate (fixed effects model) was 0.98 (95% CI 0.97; 1.00) for intra- and 0.99 (95% CI 0.98; 1.00) for inter-observer agreement. All methods were valid but with different levels of precision. The intra- and inter-observer reproducibility was high and homogeneous across studies.

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.

Diagnostic accuracy of the third molar maturity index (I3M) to assess the age of legal majority in Northern Brazil-population-specific cut-off values

International guidelines for dental age assessment have recommended the use of methods based on available population-specific data. The Third Molar Maturity Index (I_3M) was previously validated in several populations worldwide. This was the first study to evaluate the I_3M in a northern Brazilian population and to test the diagnostic accuracy of the method to distinguish between minors and adults. The sample consisted of 1.070 panoramic radiographs retrospectively collected from females (n = 595) and males (n = 475) with ages between 16 and 22 years. I_3M's original cut-off value of 0.08 was used to classify individuals below and above the age of 18. Receiver operating characteristic (ROC) curves were plotted to assess the accuracy (ACC) of the method. In females and males separately, the overall ACC was 73.1% and 80%, respectively. The overall ACC for the combined sample was 76.1%. For northern Brazilian males, the best cut-off value remained 0.08, while for females, an adjustment to 0.12 showed optimal outcomes. The new cut-off value led to an ACC of 98.5% for females, which reflected an increase of 25.5% compared to the original cut-off value. The original cut-off value proposed by I_3M was applicable to the present sample of northern Brazilian individuals. Adjustments to 0.12, however, may be encouraged to enhance the performance of the method among females.

Third molar maturity index as an efficient tool for prediction of age in a sample Indian population - A retrospective study

Introduction

The age of 18 years is an important milestone for legal matters, and developmental parameters of teeth are often used for estimation of this age. The aim of this study is to assess the efficiency of third molar maturity index (I3M) in establishing age of 18 years in Dakshina Kannada population.

Methods

A total of 700 orthopantomograms were retrieved from the archives of the radiology department of Manipal College of Dental Sciences, Mangalore. The length and the width of the open apex of the mandibular left third molar was assessed using Image J software and the Third molar maturity Index (I3M) was calculated and correlated with the age of the individual.

Results

Receiver operating characteristic (ROC) curve analysis showed the Area under curve of 0.94 and 0.96 in females and males, respectively, for prediction of age of 18 years. The cut-off of 0.08 predicted the 18-year cut-off with 97% specificity and 90.2% negative predictive value. The percentage of the accuracy was 80.23% if the I3M was <0.08.

Conclusion

The efficiency of the cut-off of 0.08 of I3M has been tested in various population including Kosovar, Peruvian, South Indian, Libyan, Montenegro, Croatian, African (Botswana), Albanian, and Serbian. Our study also shows the efficiency of the same in South Indian Dakshina Kannada population.

A test to study the influence of impaction on mandibular third molar development and forensic age estimation in a sample of south Indian children and young adults

It has been argued that the impaction of the third molars could result in delayed maturation, which, in turn, could affect age estimations in criminal proceedings. In view of this, the present study was undertaken to determine whether the impaction status could delay the chronological process of third molar mineralization in a sample of south Indian children and young adults. The orthopantomograms (OPGs) of 915 children and young adults of south Indian origin aged between 15 and 22 years were evaluated. Mineralisation stage and impaction status were determined for all lower third molars. Descriptive statistics were performed at stages D to H of Demirjian staging system. The results of independent t-test show that the impaction resulted in statistically significant slower mineralization in impacted lower third molars at stages D to F in both sexes. It was ascertained that the mean ages with the impacted lower third molars at stage G were 0.98-1.38 years higher in males and 0.50-0.80 years higher in females than those with non-impacted lower third molars. For stage H, the mean ages were 0.14-0.21 years higher in males and 0.25-0.44 years higher in females. The probabilities of being 18 years and above is higher for non-impacted lower third molars at stages G and H than those with impacted ones. It is concluded that the impaction could result in delayed maturation in the lower third molars of the studied sample. Further studies are warranted in a more diverse sample.

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.

Legal age determined by a new threshold value of third molar maturity index in subjects with impacted mandibular third molars: An orthopantomographic study in south Indian adolescents

Third molars are one of the few biological markers available for age estimation in juveniles, especially for the estimation of the 18-year-age threshold. Literature has indicated that impaction has an influence on the development of third molars, which could possibly result in age misclassifications. The present study is intended to identify an alternative cut-off value of the third molar maturity index (I3M) in impacted mandibular third molars and also to evaluate its applicability in estimating the major (≥ 18 years)/minor (< 18 years) status. A total of 1330 digital orthopantomograms (OPGs) of 665 male and 665 female south Indian adolescents aged from 15 to 22 years were collected and assessed. Eight hundred forty OPGs (63.1%) represented test sample, and 490 OPGs (36.9%) represented validation sample. I3M was measured for the total sample. Logistic regression, receiver operating characteristic (ROC) curve analysis, and Youden's index were used to test the performance of the method in the test sample. An alternative cut-off value of I3M < 0.17 was established for the highest value of the Youden's index of 0.598 for both sexes. When tested in validation sample, it has resulted in sensitivity and specificity values of 0.91 (95% CI; 0.86-0.95) and 0.90 (95% CI; 0.78-0.91) in males and 0.86 (95% CI; 0.80-0.92) and 0.90 (95% CI; 0.83-0.95) in females. In conclusion, cut-off value of I3M < 0.17 could accurately discriminate adults from minors with impacted mandibular third molars. However, more work is needed to be done among a more diverse sample to confirm these findings.

Comparison of the third molar maturity index (I3M) between left and right lower third molars to assess the age of majority: a multi-ethnic study sample

The diagnostic accuracy of the I_3M to assess the legal age of 18 years has already been tested in several specific-population samples. The left lower third molar has been extensively used for discriminating between minors and adults. This research aimed to compare the usefulness of lower third molar maturity indexes, from both left and right side (I_3ML and I_3MR), in samples originating from four distinct continents in order to examine possible differences in their accuracy values. For this purpose, a sample of 10,181 orthopantomograms (OPGs), from Europe, Africa, Asia and America, was analysed and previously scored in other studies. The samples included healthy subjects with no systemic disorders with both third molars and clear depicted root apices. Wilcoxon Signed Rank test for left and right asymmetry did not show any significant differences. Data about sensitivity, specificity, predictive values, likelihood ratio and accuracy were pooled together and showed similar results for I_3ML and I_3MR, respectively. In addition, all these quantities were high when only the I_3MR was considered to discriminate between adults and minors. The present referable database was the first to pool third molar measurements using panoramic radiographs of subjects coming from different continents. The results highlighted that both I_3ML and I_3MR are reliable indicators for assessing the legal age of 18 years old in those jurisdictions where this legal threshold has been set as the age of majority.

Study of the ethnicity's influence on the third molar maturity index (I3M) for estimating age of majority in living juveniles and young adults

Estimation of age of majority has important applications in the forensic daily practice because of the increasing demand for age estimates of unaccompanied minors. Diagnostic accuracy of I_3M to assess legal adult age of 18 years has been already tested in several specific population samples. The aim of this work was to compare the available data about sensitivity and specificity of the third molar maturity index (I_3M) from five different regional groups' radiographic samples to study possible ethnical difference. For this purpose, a sample of 6157 orthopantomograms (OPGs), coming from 15 countries, was analysed. Data about sensitivity and specificity were pooled using a bivariate modelling approach. The one-way MANOVA analysis was applied to assess the likelihood that sensitivity and specificity of the five regional groups are sampled from the same population. The result of the one-way MANOVA showed that both sensitivity and specificity did not depend from the regional groups. The obtained sensitivity was 84% (95% CI: 82% and 85%), and its specificity was 94% (95% CI: 93% and 95%). Based on these results, the I_3M was a useful statistical tool to identify whether a subject has reached the legal age of 18 years old, regardless of his or her ethnicity.

Cut-off for the legal ages in the Portuguese Population by Third Maturity Index: Measures of Accuracy

OBJECTIVES

The aim of this study is to estimate the cut-off points for the Portuguese legal ages through the I_3M, and to compare them with the methods of Demirjian, Nolla and Moorrees.

DESIGN

The lower third molars were analyzed on 348 orthopantomography's aged between 12 and 23 years in a Portuguese Population. The images were analyzed by ImageJ and the cut-off points were calculated for the respective legal ages of 14, 16, 18 and 21 years old.

RESULTS

The correlation between age and the I3M was 0.862, whereas with Demirjian's stadiums, Nolla's stages, and Moorrees' stages the correlation coefficients were 0.863, 0.842 and 0.844, respectively. For the cut-off point of 0.08 for the age of 18, a sensitivity of 78.99 %, specificity of 93.48 %, an accuracy of 88.54 %, a positive predictive value of 86.24 % and a posteriori Bayes probability of 92.82 %. The cut-off points established for the ages of 14, 16, 18 and 21 years for the Portuguese population achieved an accuracy of 83.67 %, 85.67 %, 88.54 % and 87.11 %, respectively.

CONCLUSION

Demirjian's method and Cameriere's method attain quite similar results. In certain ages, the methods of Nolla and Moorrees show higher sensitivity or higher specificity when compared to Cameriere's method, however this last method is more stable in terms of reliability and more suitable to use in the Portuguese population.

Age estimation in the living: A scoping review of population data for skeletal and dental methods

Age estimation of living individuals has become a crucial part of the forensic practice, especially due to the global increase in cross-border migration. The low rate of birth registration in many countries, hence of identification documents of migrants, especially in Africa and Asia, highlights the importance of reliable methods for age estimation of living individuals. Despite the fact that a number of skeletal and dental methods for age estimation have been developed, their main limitation is that they are based on specific reference samples and there is still no consensus among researchers on whether these methods can be applied to all populations. Though this issue remains still unsolved, population information at a glance could be useful for forensic practitioners dealing with such issues. This study aims at presenting a scoping review and mapping of the current situation concerning population data for skeletal (hand-wrist and clavicle) and dental methods (teeth eruption and third molar formation) for age estimation in the living. Two hundred studies on the rate of skeletal maturation and four hundred thirty-nine on the rate of dental maturation were found, covering the period from 1952 and 2020 for a total of ninety-eight countries. For most of the western and central African countries there are currently no data on the rate of skeletal and dental maturation. The same applies to the countries of the Middle East, as well as the eastern European countries, especially as regard the skeletal development.

Third molar maturity index and legal age in different ethnic populations: Accuracy of Cameriere's method

Molar development is widely accepted as a reliable indicator of chronological age in a forensic context. A quantitative method for age estimation has been proposed by Cameriere et al. based on the relationship between chronological age and the third molar maturity index (I_3M), which is the ratio between the two apical pulp widths and the total tooth length. Cameriere's cut off value of 0.08 was found to be a reliable tool in assessing the threshold of 18 years of age. The aim of this study was to evaluate the accuracy of the I_3M in different ethnic populations focusing on its specificity (subjects correctly classified as <18 years based on I_3M >0.08) and sensitivity (subjects correctly classified as ≥18 years based on I_3M <0.08). A review of 22 scientific articles was performed, representing data from panoramic radiographs of 12,286 individuals (5723 males and 6563 females) from all over the world, including some ethnical subgroups. The I_3M showed an overall sensitivity for both sexes ranging from 51.8% to 93.4% and a specificity ranging from 86.2% to 100%. The proportion of correctly classified individuals ranged from 74% to 95%. These results can be useful to refer the age estimation with the margin of error of subjects correctly classified as minors (specificity) or adults (sensitivity), according to sex, ethnicity and geographical distribution. The I_3M can be considered a suitable method for estimating adulthood in forensic settings, regardless of sex. However, ethnic group can affect the accuracy.

Validation of the Third Molar Maturation Index (I3M) to assess the legal adult age in the Portuguese population

Age estimation is a major step in forensic and legal procedures. Its relevance has been increasing due to growing society issues, such as identification of missing people, crimes against minors or lack of valid identification papers from locals or foreigners. Evaluation of the cut-off value of the Third Molar Maturation Index (I_3M) = 0.08 for discriminating minors from adults in the Portuguese population. The left lower third molars were analysed by applying a specific cut-off value of 0.08 determined by Cameriere et al. in 2008. A sample of 778 digital panoramic radiographs of a representative Portuguese sample (442 females and 336 males), in the age range of 12–24 years (mean age 17.7 ± 2.98 years in females and 18.1 ± 3.0 years in males), was retrospectively evaluated. I_3M decreased as the real age gradually increased in both sexes. The 0.08 cut-off score was valuable in discriminating adults from minors. According to the pooled results, the accuracy, by means of area under the curve, was 92.8% (95% confidence interval (CI) 91.0–94.6%). The proportion of correctly classified subjects (sensitivity) was 90.7% (95% CI 88.7–92.8%) and the specificity was 94.9% (95% CI 93.3–96.4%). The results show that I_3M is a valuable method to differentiate minors from adults in the Portuguese population.

Age estimation in Brazilian adults by Kvaal's and Cameriere's methods

The aim of this study was to verify the precision and applicability of two methods of age estimation, Kvaal's and Cameriere's methods, among Brazilian adults. A sample composed of periapical radiographs of canine teeth belonging to 320 Brazilian adults was analyzed, divided into groups according to sex (male and female) and age group (20-29 years, 30-39 years, 40-49 years and 50-59 years). Kvaal's method presented better results when compared to the results of Cameriere's method in the general evaluation of each canine tooth, except for the upper left canine (tooth 23), which presented a mean error (ME) with no statistically significant difference between the methods (Kvaal: ME = 7.43, p = 0.4991, Cameriere: ME = 7.55, p = 0.6982). In the evaluation by age groups, Kvaal's method presented a lower variation between the real age and estimated age when applied to the age groups of 20-29 years and 30-39 years compared to the results provided by Cameriere's method. With respect to the groups aged 40 to 49 years and 50 to 59 years, Cameriere's method presented better performance than the results provided by Kvaal's method. The methods of estimating age proposed by Kvaal and Cameriere are simple and nondestructive and have demonstrated reproducibility and reliability. The Kvaal method was more accurate for the age groups of 20-29 and 30-39 years, and for those over 40 years, the Cameriere method was the most accurate.

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.

Cameriere's third molar maturity index in assessing age of majority: a study of a French sample

Forensic age estimation is a challenging field in forensic sciences because of the increase of migratory flows. Medicolegal age assessment is a key point because it has many implications for authorities. Dental age estimation is an essential part of the global age assessment. The aim of this study was to evaluate and test the accuracy of Cameriere's cutoff values of the third molar maturity index (I3M) in assessing legal adult age of 18 years in a French population. The sample was constituted of 431 orthopantomograms performed between January 2014 and August 2017 on patients aged between 14 and 22 years. The reproducibility and repeatability of the method were high. Age distribution gradually decreases as I3M increases in both sexes. 0.08 seemed to be the best I3M cutoff. For females, the sensitivity and specificity of the test were 74.51% and 88.23%, respectively. The sensitivity and specificity for males were 92.19% and 88.35%, respectively. The accuracies were 80.74% for female, 90.57% for male. Estimated post-test probabilities were 0.879 for female and 0.899 for male. To conclude, the specific cutoff value of I3M ˂ 0.08 may be a useful additional tool in discriminating adults and minors in French population.

Validation of the Third Molar Maturation Index to estimate the age of criminal responsibility in Northeastern Brazil

The estimation of the age of majority is crucial to determine the legal accountability of an individual. With this purpose, the analysis of the dental development process has proven to be an effective, elucidatory method. This study investigated the applicability of the Third Molar Maturation Index (I_3M), proposed by Cameriere et al. (2008), to estimate the age of majority in a sample of Northeastern Brazilians using panoramic radiographs. Adobe® Photoshop® CS4 (Adobe Systems Incorporated, San Jose, California, USA) software was used to obtain the I_3M index measurements in a sample of radiographs from a dental radiology clinic located in Northeastern Brazil. Radiographs of individuals aged between 14 and 23 years were included in the sample, except if showing absence, distortions, pathological alterations or suspected pulp impairment of the tooth #38 (third lower left molar), as the method applies exclusively to this element. Of the total sample of radiographs previously obtained for diagnostic and/or orthodontic purposes (n=394), 185 were from males and 209 from females, of which 217 corresponded to 18 year-olds or older and 177 were from minors. Logistic regression and predictive values of sensitivity, specificity and Receiver Operating Characteristic (ROC) curve (α=0.05) were used. The cutoff point originally proposed for the I_3M index (0.08) presented a sensitivity of 88.4% and a specificity of 73.2%, with accuracy (area under the ROC curve) of 80.8% (95%CI: 76.4-85.3%) for the Northeastern Brazilian population, as well as a correct age classification in 80.2% of the sample. The method estimated accurately 73.7% of the cases corresponding to "18 years or older" and 88.1% of the cases "under 18years" (p=0.000). Among the sexes, the correct age classification rate of the method was 84.3% for males and 76.6% for females, with no statistically significant difference between the match and error rates and between the sexes (p≥0.05). In conclusion, the Third Molar Maturation Index could accurately distinguish the age of adolescents and young adults of both sexes aged 18 years or under/older in a Brazilian population.

Contribution of third molar eruption to the estimation of the forensic age of living individuals

Forensic age estimation of a living individual is frequently performed in clinical forensic medicine. Medicolegal physicians are usually called upon by the authorities to estimate the age of a living person requesting asylum or to determine whether a suspected offender is subject to juvenile or adult criminal law. Dental age is one of the parameters studied to estimate biological age. Several methods are used, and among these, analysis of the eruption of the third molar (M3) on an orthopantomogram (OPG) is one of the common methods. The objective of the study was to analyse the contribution of M3 eruption to age estimation, in particular with regard to the threshold of 18 years of age, in a sample of individuals examined in a French university hospital. The stage of wisdom tooth eruption of all individuals aged between 15 and 24 years, who had an OPG performed between 1 January 2013 and 31 December 2015, was interpreted using a three-stage scoring system. In total, 557 OPGs (340 males and 217 females) were included. None of the stage scores allowed a distinction between minors and majors, for either sex. Overall, 85% of females and 98% of males with four M3s in stage 3 (complete emergence in the occlusal plane) were majors.

Third molar maturity index for indicating the legal adult age in southeastern France

The estimation of age in living subjects is today a significant issue because of the increase in the situations in which it arises and its legal consequences. In line with the Study Group on Forensic Age Diagnostics of the German Association of Legal Medicine's recommendations, it is based on the concomitant use of physical examination and methods for estimating bone age and dental age. Given the variations between the populations, the use of the latter requires their validation on all the ethnic groups on which they can be used. This aim of this study was to access the interest of the Cameriere's third molar maturity index (I_3M) to indicate if an individual had reached the age of 18 in a sample of individuals from southeastern France. The studied sample consisted of OPTs 339 (184 females and 155 males) subjects aged between 14 and 22 years old. A logistic regression analysis with the adult age and minor age as dichotomous dependent variable and gender and I_3M as predictor variables showed that gender was not statistically significant in discriminating adults and minors. The receiver operating curve (ROC) analysis showed the best discrimination performance of the specific cut-off value of I_3M<0.08 in discriminating adults from minors. The proportion of accurate classification was 0.897 and 0.916 for females and males, respectively. The specificity (Sp) and sensitivity (Se) results for females were 0.962 and 0.813, respectively. Sp and Se for males were 0.953 and 0.871, respectively. The Bayes post-test probability was 0.961 and 0.955 in females and males respectively. Obtained results showed that a cut-off value of I_3M<0.08 may be an additional tool for indicating adult age in the tested population.

The third molars for indicating legal adult age in Montenegro

AIM

From a medico-legal and penalty point of view, it is essential to conclude if an individual is a minor or an adult (18 years of age). Methods based on the third molar development have been used for this purpose. The present article aims to verify the Nolla's stages of mineralization of the third molars and a third molar maturity index (I3M) which is based on the measures of the projections of open apices normalized by their height in the sample of Montenegrins.

METHOD AND SAMPLE

The sample consisted of 683 panoramic radiographs (324 males and 359 females) between 13 and 24 years of age. The specific mineralization stages of Nolla and the cut-off value of I3M < 0.08 was used to discriminate adults and minors.

RESULTS

The best performance in discriminating adults and minors was for I3M < 0.08 followed by the Nolla stage 9. For I3M < 0.08 the results demonstrated high sensitivity of 0.92 and 0.82 and specificity of 0.94 and 0.96 in males and females, respectively. The proportions of correctly classified individuals were 0.93 in males and 0.89 in females. The Nolla stage 9 demonstrated the sensitivity of 0.95 and 0.85 and the specificity of 0.84 and 0.90 in males and females, respectively. The proportions of correctly classified individuals were 0.90 in males and 0.87 in females.

CONCLUSION

The suggested value of I3M < 0.08 followed by Nolla stage 9 can be used to discriminate adults from minors with high specificity.

Accuracy of the third molar maturity index in assessing the legal age of 18 years: a systematic review and meta-analysis

The age estimation is a complex procedure required in the daily practice of legal medicine. The maturity of third molars stands out by the age of 18 because these teeth are still in development. This systematic review aimed to assess the accuracy of the third molar maturity index (I _3M), proposed by Cameriere et al. (2008), in discriminating whether an individual is under or over 18 years. Seven electronic databases were screened: PubMed, Scopus, ISI Web of Science, Cochrane Library, LILACS, SIGLE, and CAPES. Eligible studies included an assessment of I _3M accuracy at the 0.08 cut-off value. The quality assessment was performed by using QUADAS 2. Three meta-analyses (MA) were accomplished: overall, one for males and another for females. From 2397 articles identified, 16 met the eligibility criteria. Of these, two showed high risk of bias, one in the reference standard domain and the other in the flow and timing domain. The percentage of individuals correctly classified ranged from 72.4 to 96.0%. The overall MA showed pooled sensitivity of 0.86 (0.84 to 0.87; p = 0.0000) and pooled specificity of 0.93 (0.92 to 0.94; p = 0.0000). The AUC (area under the summary receiver operator characteristics curve) and DOR (diagnostic odds ratio) values were, respectively, 0.9652 and 104.68, indicating an overall high discrimination effect. Separately, better results of accuracy were found for males. High heterogeneity was achieved for both sensibility (94.6%) and specificity (88.8%). We conclude that the I _3M is a suitable and useful method for estimating adulthood regarding forensic purposes, regardless of gender.

The third molar maturity index in indicating the legal adult age in Kosovar population

The third molar tooth, known as the "wisdom tooth," is the only tooth that can be used to determine legal adult age. This study aimed to test the accuracy of Cameriere's third molar maturity index (I_3M) in assessing the legal adult age of 18 years in the Kosovar population. Orthopantomographs (OPTs) of 1221 healthy living Kosovar individuals, aged between 12 and 23 years and with no congenital or developmental anomalies, were analyzed. Intra-class correlation coefficients were 0.858 (95% CI, 0.786 to 0.906) and 0.852 (95% CI, 0.779 to 0.903) for intra-rater and for inter-rater agreement, respectively. The sample was divided into training dataset (800 OPTs) and test dataset (421 OPTs). The training dataset was used to generate the logistic regression model, while the test dataset was used to study the performance of the model. I_3M and gender as independent variables and adult age (≥ 18 years) or minor age (< 18 years) as the dependent variable were used for logistic regression analysis. The receiver operating curve (ROC) analysis was used to determine the specific cut-off value of I_3M for predicting adult age. The results showed that only I_3M statistically significantly contributed to discriminating adults and minors. ROC analysis showed that the cut-off value of I_3M < 0.08 was the best in discriminating adults and minors. An analysis of the test dataset (421 OPTs) showed that as I_3M decreased the age gradually increased. The performance of the cut-off value of I_3M < 0.08, to discriminate between adults and minors, was analyzed by contingency tables for both sexes. In males, the accurate classification (Acc) was 0.968 (95% CI, 0.926 to 0.985), the sensitivity (Se) was 0.962 (95% CI, 0.925 to 0.978), and the specificity (Sp) was 0.976 (95% CI, 0.929 to 0.995). The Bayes post-test probability (Bayes PTP) was 0.975 (95% CI, 0.905 to 1.00). In females, Acc was 0.909 (95% CI, 0.870 to 0.917), Se and Sp were 0.826 (95% CI, 0.787 to 0.834) and 0.991 (95% CI, 0.953 to 1.00) respectively, while Bayes PTP was 0.989 (95% CI, 0.926 to 1.00). Our data support the usefulness of I_3M < 0.08 to indicate legal adult age in a Kosovar population.