Molar Maturity Research Articles

Evaluation of modified demirjian and cameriere third molar maturity index (I3M) on dental age estimation in North Indian population: A comparative study

Evaluation of modified demirjian and cameriere third molar maturity index (I3M) on dental age estimation in North Indian population: A comparative study

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

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

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 (≥ 18years)/minor (< 18years) status. A total of 1330 digital orthopantomograms (OPGs) of 665 male and 665 female south Indian adolescents aged from 15 to 22years 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.

Mandibular third molar maturation stage as indicator for the legal adult age in an Egyptian sample.

Determination of the age of majority is of critical importance in forensic and legal practice. This study aimed to assess the mandibular third molar maturation stage in discriminating adults and minors in an Egyptian population sample using two methods: Cameriere's third molar maturity index (I3M) and Demirjian's stage of maturation; further, the I3M cut-off value of < 0.08 for age 18 years and older was tested. The study included 350 digital panoramic radiographs of 14-24 years old participants. The effectiveness of I3M < 0.08 and Demirjian's stages were assessed using sensitivity, specificity, accuracy, post-test probability, positive likelihood ratio, and negative likelihood ratio. Receiver operating characteristic (ROC) curves were constructed to detect the overall effectiveness of I3M and Demirjian's stages to determine adults. I3M < 0.08 showed accuracy, sensitivity, specificity, post-test probability, positive and negative likelihood ratios of 88.65%, 91.74%, 83.67%, 90.6%, 5.62 and 0.10 respectively in males, and 82.76%, 80.16%, 87.04%, 91.03%, 6.18 and 0.23 in females. Stage H showed the best specificity and post-test probability within Demirjian stages; 91.84% and 94.06% in males and 90.74% and 91.84% in females. Both I3M and Demirjian's stage H of the mandibular third molar were useful indicators for discriminating between Egyptian adults and minors. The cut-off value of I3M < 0.0625 in males and I3M < 0.104 in females showed a better discrimination performance than I3M < 0.08 among Egyptians.

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 I3M to assess legal adult age of 18years 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 (I3M) 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 I3M was a useful statistical tool to identify whether a subject has reached the legal age of 18years old, regardless of his or her ethnicity.

Assessment of second (I2M) and third (I3M) molar maturity indices individually and in combination (I2M+3M) and the sum of the seven mandibular teeth indices (S) for the legal age thresholds of 12 and 15 years in a Turkish sample

ABSTRACT The present study aimed to assess the performance of second (I2M) and third (I3M) molar maturity indices, the sum of both indices (I2M+3M), and the sum of the seven mandibular teeth indices (S) in terms of determining whether an individual is at least 12 or 15 years old. The panoramic radiographs of 763 individuals aged between 10–17 years were analysed. For the 12-year age threshold, I2M was found to be the highest specific indicator for both sexes. The optimal cut-off values for the I2M were determined to be 0.072 in females and 0.106 in males. The sensitivity, specificity, and area under the ROC curve (AUC) were 0.749, 0.978, and 0.925 in females, while they were 0.776, 0.953, and 0.925 in males, respectively. With regard to the 15-year age threshold, an optimal I2M cut-off value of 0.026 was established for females, as it showed the best discriminative ability. The sensitivity, specificity, and AUC were 0.893, 0.779, and 0.885, respectively. For males, an optimal cut-off value of 0.593 was obtained for I2M+3M with the highest specificity (0.900) and AUC (0.931) as well as a sensitivity of 0.857. In conclusion, the identified cut-off values may represent alternative methods in forensic age diagnostics.

Testing international techniques for the radiographic assessment of third molar maturation.

BackgroundTo assess the radiographic third molar maturation with internationally developed techniques for age estimation. Material and MethodsThe study analyzed 1,062 panoramic radiographs of patients treated at the School of Dentistry of the University of Passo Fundo/RS/Brazil, between 2009 and 2020. The patients were separated into ages between 15.00 and 23.99 years and, for each radiograph, the third molars were classified into stages from 1 to 10, with the subsequent application of one of the formulae proposed by Gunst et al. A dichotomous variable indicating whether each individual was younger or older than 18 was calculated from the chronological age of the individuals. A logistic regression model was adjusted to assess whether the third molar stages are correlated with the age of individuals. ResultsThe error indicators between estimated and chronological ages showed that mean errors closer to zero are seen in the 18-18.9 and 17-17.9 age groups, respectively. Male individuals were earlier in terms of dental mineralization but there were no significant differences between sexes regarding the applicability of the method. The ROC curve shows that the analysis of a single third molar for age estimation gives a maximum of 70.4% reliability. ConclusionsThe moderate performance of the technique tested in the present study justify future country-specific corrections to improve age estimation from the radiographic assessment of third molar maturity. Key words:Dental age estimation, forensic dentistry, radiology, third molar.

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 etal. based on the relationship between chronological age and the third molar maturity index (I3M), 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 I3M in different ethnic populations focusing on its specificity (subjects correctly classified as <18 years based on I3M >0.08) and sensitivity (subjects correctly classified as ≥18 years based on I3M <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 I3M 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 I3M can be considered a suitable method for estimating adulthood in forensic settings, regardless of sex. However, ethnic group can affect the accuracy.

Forensic Validity of the Third Molar Maturity Index (I 3M) for Age Estimation in a Russian Population.

The aim of this cross-sectional study was to test the accuracy of the third molar maturity index (I3M) cut-off value (0.08) to distinguish between individuals above and below the adult age of legal responsibility (18 years) in a Russian population. A sample of 571 digital panoramic radiographs of healthy Russian minors and young adults (363 females and 208 males), aged between 14 and 24 years, was evaluated. The lower left third molars were analyzed by applying the cut-off value of 0.08 determined by Cameriere et al. (2008). Lin's concordance correlation coefficient (ρc) and Cohen's kappa coefficient (κ) showed that repeatability and reproducibility are high for both intra- and interobserver errors. The I3M value decreased with age in both sexes. Age distribution gradually decreases as I3M increases in both girls and boys. In the male group, molar maturity stages 0-0.04, 0.04-0.08, 0.08-0.3, 0.3-0.5, and 0.9-1.4 were reached slightly earlier than in the female group. The results demonstrated that sensitivity is 0.96 in boys and 0.93 in girls; associated specificity values were both 0.98. The cut-off value of I3M is statistically robust and thus valid for forensic application in a Russian population to determine whether or not a subject has reached 18 years of age. Finally, we compared our results with those of other studies in which the same I3M cut-off value was tested on different populations. The method is novel as it is reliable and easily reproducible, thus ensuring a universal way of comparing the results obtained (based on a cut-off value) among many populations, in order to develop an ever-increasing database.

Performance and comparison of the London Atlas technique and Cameriere’s third molar maturity index (I3M) for allocating individuals below or above the threshold of 18 years

Age estimation is an important procedure in the forensic practice, especially when it comes to the criminal imputability of juvenile offenders. This study aimed to compare two radiographic methods for dental age estimation in a population of subadults from Northeast Brazil considering their performance on allocating individuals below or above the age threshold of 18 years. A cross-sectional observational study was designed. The sample consisted of 1200 panoramic radiographs of Northeastern Brazilian females (n = 600) and males (n = 600) aged between 16 and 21 years. Dental age estimation was performed using the London Atas technique and Cameriere’s third molar maturity index (I3M). Statistical tests were performed to assess the sensitivity, specificity and accuracy of the two methods on distinguishing individuals below or above the legal age threshold of 18 years. Considering the total sample, the London Atlas technique reached sensitivity of 92.3%, specificity of 56% and accuracy of 79.9%. I3M revealed sensitivity of 94.1%, specificity of 55.4% and accuracy of 79.8%. Specificity rates systematically decreased when the sample was progressively stratified based on age groups that narrowed close to 18 years. The methods performed very similar (0.878). The combination of methods did not improve the performance on dental age estimation. The London Atlas and the I3M methods similarly distinguished Brazilian individuals as minors or not. Their performance, however, was suboptimal because of the low rates of specificity that could negatively influence on Court decisions. In other words, the methods could wrongly classify minors into the age of legal majority (culminating in false positives). In practice, the misleading classification could restrict individual rights (in the civil scenario) or even support more severe penalties (in the criminal scenario).

Validity assessment of the third molar maturity index (I3M) in a Lebanese sample of adolescents and young adults

ABSTRACT The validity of third molar index (I3 M = 0.08) for discriminating minors from adults was tested in a sample of 620 panoramic radiographs of Lebanese subjects (293 females and 327 males), aged between 14 and 23 years. The technical error of measurements (TEM), the relative technical error of measurements (rTEM), the coefficient of reliability (R) and the Intraclass Correlation Coefficient (ICC) were calculated for testing intra- and inter-observer agreement. The I3 M values gradually decreased as age (years) increased across all the age groups in both sexes. For females, the sensitivity and specificity of the test were 0.61 (95% CI: 0.53–0.69) and 0.97 (95% CI: 0.93–0.98), respectively. The sensitivity and specificity for males were 0.63 (95% CI: 0.56–0.70) and 0.89 (95% CI: 0.83–0.93), respectively. The accuracy values (number of correct assessments) were 0.79 (95% CI: 0.74–0.83) for females and 0.74 (95% CI: 0.70–0.79) for males. Estimated post-test probabilities were 0.97 (95% CI: 0.91–0.99) for females and 0.90 (95% CI: 0.83–0.94) for males. The I3 M was a useful further indicator for discriminating between adults and minors in this Lebanese sample of adolescents and young adults.

Ethical issues in age assessment by the third molar development

ABSTRACT According to international regulations, unaccompanied minor status determination implies a different set of rights, needs and entitlements than migrant adults. In forensic scenarios, the age assessment of refugee and asylum seekers who do not have reliable documentation is based on the application of different medical and non-medical methods. A multidisciplinary and holistic approach based on a gradual implementation of these methods is recommended worldwide. Many healthcare professionals consider medical age assessment, especially when performed through radiology, highly intrusive and ethically questionable because it is conducted without medical or therapeutic benefits. About dental examination, the evaluation of the third molar development can provide very useful information on the crucial age limit of 18 years. Demirjian’s scoring system and the third molar maturity index (I3 M) developed by Cameriere et al. (2008) are the two most common quantitative methods for dental age estimation. An ethical evaluation of the dental age estimation performed by these radiological methods through the four principles of biomedical ethics (autonomy, beneficence, non-maleficence and justice) is discussed here.

Applicability of newly derived second and third molar maturity indices for indicating the legal age of 16years in the Southern Chinese population.

In China, forensic age estimation in the living has become increasingly important in these few years. Due to increasing juvenile crimes, the age of 16years has become the legal age threshold for determining whether the juvenile criminal law or adult criminal law applies to the citizen. This study aimed to assess new cut-off values of the third molar maturity index (I3M) and second molar maturity index (I2M) at the legal age threshold of 16years in Southern Chinese population and then to compare the applicability of the cut-off values of I3M and I2M we set for discriminating whether a subject is≥16years. Orthopantomograms (OPGs) of 671 healthy Southern Chinese subjects (332 males and 339 females), aged between 10 and 20years, were studied. Logistic regression analysis was performed with chronological age (below 16years and over 16years) as a dichotomous dependent variable and, I3M, I2M, and sex as predictive variables. The high p-value for sex (p=0.861) reveals that this factor was not statistically significant in assessing the legal age of 16. The cut-off values of I3M<0.38 and I2M<0.03 were identified and used to distinguish between individuals who were or were not aged≥16years. Compared with a single predictor (I3M) alone, combining I3M and I2M can be more reliable for determining whether an individual is aged more than 16years. We found that accuracy was 88.52% (95% confidence interval CI, 86.11-90.94%) and sensitivity and specificity were 77.96% (95% CI, 74.82-81.10%) and 97.28% (95% CI, 96.04-98.51%), respectively. The estimated Bayes post-test probability was 99.12% (95% CI, 98.41-99.83%). In conclusion, combining I3M and I2M may be useful in legal and forensic practices to determine the legal age of 16years in Southern Chinese individuals.

Assessment of third molar maturity index for legal age threshold of 18 in a sample of Turkish individuals

ABSTRACT The aim of this study was to test the performance of the third molar maturity index (I3M) for discriminating between adults and minors. Panoramic radiographs of 760 individuals aged 11 to 25 years were assessed and validity of I3M < 0.08 was tested. A receiver operating characteristic (ROC) curve analysis and Youden’s index were used to test the performance of the method. The sensitivity and specificity were 0.554 (95% confidence intervals [CI], 0.487–0.619) and 0.962 (95% CI, 0.926–0.983) in females, 0.750 (95% CI, 0.666–0.829) and 0.949 (95% CI, 0.910–0.974) in males, respectively. The proportion of correctly classified individuals was 0.747 (95% CI, 0.703–0.786) and 0.884 (95% CI, 0.815–0.895) in females and males, respectively. In addition, an optimal cut-off value was determined as I3M < 0.19 for females. When we used this cut-off value in females, sensitivity, specificity and accuracy were as follows: 0.820 (95% CI, 0.764–0.867), 0.833 (95% CI, 0.775–0.880) and 0.826 (95% 0.768–0.843). The I3M gave better results when using a sex-specific cut-off value in a Turkish sample.

Validation of the third molar maturity index cut-off value of

Having a reliable, inexpensive and simple method to estimate 18years of age would be of help in the forensic field. This study aimed to test the accuracy of the third molar maturity index (I3M) in indicating the legal adult age of 18years. 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 22years. A cut-off value of I3M<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 I3M. A stepwise logistic regression analysis showed that both I3M and sex contribute to the regression model to discriminate adults (≥18years) from minors (<18years), while a receiver operating curve (ROC) analysis indicated some better accuracy of I3M<0.12 in females, without statistically significant difference when compared to I3M<0.08. The results of this study show that the cut-off value of I3M<0.08 may help to discriminate Eastern Chinese adults from minors. However, further study should evaluate the usefulness and possible variability of I3M cut-off value in a specific population before used for legal and forensic procedures.

Applicability of the third molar maturity index for assessment of age of majority in Eastern China.

From a legal and penalty point of view, it is essential to conclude if an individual has reached the legal age (also known as age of majority). Although Cameriere's third molar maturity index (I3M) has been used to discriminate between adults and minors, no study has tested the applicability of I3M in the Eastern Chinese population. The aim of this study was to assess the validity of the region-specific cut-off value of I3M for discriminating minors from adults in an Eastern Chinese population. Five hundred fifty-six subjects (276 males and 280 females) aged 14-24 years participated in this study. A logistic regression analysis was conducted by considering the adult and minor ages as dichotomous dependent variables and I3M and sex as predictor variables. The results showed that sex was not statistically significant in distinguishing adults and minors. The receiver operating curve analysis showed the best performance of the cut-off value of I3M < 0.08 in discriminating adults from minors. Furthermore, the diagnostic test showed the proportion of accuracy was 90.22% in males and 86.43% in females. The sensitivity and specificity for males were 88% and 94.06%, respectively, while those for females were 83.71% and 91.18%, respectively. The estimated Bayes post-test probability was 97.18% and 96.01% in males and females respectively. Therefore, I3M < 0.08 may be a useful tool for indicating the legal age in Eastern Chinese population.

Accuracy of the cutoff value of the third molar maturity index: an Egyptian study

BackgroundThis study aimed to test the sensitivity and specificity of the third molar maturity index (I3M) cutoff value to discriminate between individuals above and below 18 years of age in an Egyptian sample.Material and methodsDigital images of 247 orthopantographs (97 boys and 150 girls) were evaluated. The cutoff value of I3M obtained from the results of Cameriere et al. (Int J Legal Med 122:493–497, 2008) was evaluated in both girls and boys.ResultsSensitivity (the proportion of individuals being 18 years of age or older) was 95% and 73% in boys and girls, respectively. Meanwhile, specificity (the proportion of individuals younger than 18) was 100% in boys and 97% in girls. The proportion of correctly classified boys was 97% while it was 59% in girls.ConclusionIt can be concluded that the third molar maturity index can discriminate between individuals who are 18 years and over and those under 18 with higher accuracy in boys.

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 18years in a French population. The sample was constituted of 431 orthopantomograms performed between January 2014 and August 2017 on patients aged between 14 and 22years. 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.

New regression models for dental age estimation in children using third molar maturity index: A preliminary analysis testing its usefulness as reliable age marker.

This paper concerns a method to estimate age in children using third molar maturity index (I3M) as independent variable and age as the dependent variable. Total of 1283 digital orthopantomograms (OPTs) of south Indian children aged between 7 and 22 years was included. Training sample of 933 OPTs was used to derive regression formulae, and validation sample of 350 OPTs used to verify accuracy of newly derived regression models. Regression analysis performed revealed that cubic function gave the best correlation between the studied variables. The models exhibited a high correlation coefficient for third molar development in both sexes (0.81 for boys and 0.84 for girls). When new models were verified, slight overestimation of dental age i.e., 0.2 years in boys and 0.13 years in girls was observed. Therefore, we conclude by recommending newly derived regression models as they provided better age predicting performances.

A cut-off value of third molar maturity index for indicating a minimum age of criminal responsibility: Older or younger than 16 years?

Providing appropriate legal mechanisms, that evaluate the progression of development from the age of childhood innocence to maturity and full responsibility, considered one of the difficult areas of criminal justice policy. The minimum age of criminal responsibility (MACR) in children varies among countries and differs widely owing to history and culture. Due to rising and brutality of criminal offenses, particularly by juveniles, few countries have lowered the minimum age of criminal responsibility, and many have considered/considering to do the same. India is one such country in which is under the proposal of lowering the age of criminal responsibility to 16 years. As there is lack of useful age assessment methods, that can indicate whether if the individual in question is younger (<16 years) or older than MACR (≥16 years), the present study was undertaken to derive a specific cut-off value of the third molar maturity index (I3M) for this purpose. The sample consisted of 1078 orthopantomograms (OPTs) from Andhra Pradesh, India, aged between 11 and 20 years (45.4% males and 54.6% females). The reproducibility of I3M was calculated by intra-class correlation coefficients, which showed an intra-rater and inter-rater agreement of 0.912 and 0.891, respectively. The sample was divided into training dataset (819 OPTs), to test I3M and gender as independent variables and MACR as a dependent variable by logistic regression analysis, and test dataset (259 OPTs). A receiver operating curve (ROC) analysis was performed to evaluate the specific cut-off value of I3M for predicting MACR status. A logistic regression analysis showed that gender was not statistically significant for predicting MACR status while ROC analysis indicated a cut-off value of I3M = 0.293 as best for predicting MACR status. The performance of derived cut-off value was tested in a test data set. The sensitivity of the test was 90.6% and 90%, while specificity was 86% and 87.1% in males and females, respectively. The proportion of correctly classified individuals was 88.0% and 88.7% in males and females, respectively. The estimated Bayes post-test probability in males was 87.2% and while in females it was 88.3%. The results highlight the contribution of the derived cut-off value of I3M for discriminating individuals around MACR and should be evaluated in other populations.