Development of third molar and Third molar index: I3M Global observations

Uno dei contributi principali dell\u2019odontologia forense \ue8 riguardo alla stima della maggior et\ue0. In molti stati l\u2019et\ue0 piena di responsabilit\ue0 criminale \ue8 definita al 18simo anno di et\ue0. Il terzo molare sembra un indicatore di questa fascia di et\ue0 particolarmente accurato anche perch\ue9 poco influenzato da fattori come la nutrizione la dieta e fattori socio economici. Partendo da questi presupposti l\u2019AgEstimation project ha sviluppato un metodo quantitativo per definire se un soggetto sia maggiorenne o meno misurando I3M index, ottenuto dal rapporto fra la misura degli apici del terzo molare e la sua lunghezza. Il metodo \ue8 stato testato, con successo, su campioni provenienti da diversi paesi. Lo scopo di questa tesi \ue8 di dare una risposta ad una domanda importante. Sebbene siano stati fatti test su molte popolazioni, quanto si applicabile su popolazioni nuove ed inoltre se ci sia una valenza

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

Abstract Background This 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 methods Digital 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. Results Sensitivity (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. Conclusion It 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

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 (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 6518 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

Assessment of second (I2M) and third (I3M) molar indices for establishing 14 and 16 legal ages and validation of the Cameriere's I3M cut-off for 18 years old in Chilean population

AIMS:The evaluation of the cutoff value of I3M = 0.08 for discriminating black South African minors from adults, and its relationship with chronological age. MATERIAL AND METHODS:A sample of 833 panoramic radiographs of healthy black South African subjects (500 females and 333 males), in the age range of 14 to 24 years (mean age 17.67 years in females and 17.42 years in males), was retrospectively evaluated. RESULTS:ICC values were 99.10% (95% CI 97.70 to 99.70%) and 99.20% (95% CI 98.00 to 99.60%), for the intra- and inter-observer reliability, respectively. I3M decreased as the real age gradually increased in both sexes. According to the logistic regression model, the variable sex was not significant when the probability that an individual is 18 years or older was calculated. The I3M = 0.08 was valuable in discriminating between adults and minors. The overall accuracy (ACC = fraction of accurately classified subjects) is 0.90 (95% CI 0.87-0.91); the proportion of correctly classified subjects (Se = sensitivity) is 0.80 (95% CI 0.76-0.84), and specificity (Sp) is 0.95 (95% CI 0.93-0.97). The PPV (predictive positive value) is 0.96 (95% CI 0.95-0.97), and the negative predictive value is 0.76 (95% CI 0.72-0.80). CONCLUSION:The results show that I3M is a valuable method to distinguish subjects who are around legal adult age in South Africa

Carpals and epiphyses of radius and ulna as age indicators using longitudinal data: a Bayesian approach

The aim of this study is to develop a new formula for age estimation in a longitudinal study of a sample from the radiological collection of wrist bones of growing infants, children, and adolescents recorded at the Burlington Growth Centre. A sample of 82 individuals (43 boys and 39 girls), aged between 3 and 16 years, were analyzed with a total of 623 X-rays of left hand-wrist bones by measuring the area of carpal bones and epiphyses of the ulna and radius (Bo) and carpal area (Ca). The intra-class correlation coefficient (ICC) and its 95% confidence interval were used to evaluate intra-observer agreement. Hierarchical Bayesian calibration has been adopted to exceed the bias deriving from the classical regression approach used for age estimation in forensic disciplines, since it tends to overestimate or underestimate the age of the individuals. Calibration distributions of the dataset obtained by the evaluation of BoCa (the ratio of Bo and Ca) suggested mean absolute errors (MAE) of 1.07 and 1.34 years in boys and girls, respectively. The mean interquartile range (MIQR) was 1.7 and 2.42 years in boys and girls, respectively. The respective bias of the estimates was βERR = - 0.025 and - 0.074. Furthermore, a correspondence between different BoCa values and estimated age with its standard deviation (SD) was calculated for boys and girls, respectively. In conclusion, the Bayesian calibration method appears to be suitable for assessing both age and its distribution in subadults, according to hand-wrist maturity. Furthermore, it can easily incorporate other age predictors, obtaining a distribution of the subjects with multivariate predictors

Third molar development by measurements of open apices in an Italian sample of living subjects

The aim of this study is to analyse the age-predicting performance of third molar index (I3M) in dental age estimation. A multiple regression analysis was developed with chronological age as the independent variable. In order to investigate the relationship between the I3M and chronological age, the standard deviation and relative error were examined. Digitalized orthopantomographs (OPTs) of 975 Italian healthy subjects (531 female and 444 male), aged between 9 and 22 years, were studied. Third molar development was determined according to Cameriere et al. (2008). Analysis of covariance (ANCOVA) was applied to study the interaction between I3M and the gender. The difference between age and third molar index (I3M) was tested with Pearson's correlation coefficient. The I3M, the age and the gender of the subjects were used as predictive variable for age estimation. The small F-value for the gender (F ¼ 0.042, p ¼ 0.837) reveals that this factor does not affect the growth of the third molar. Adjusted R2 (AdjR2 ) was used as parameter to define the best fitting function. All the regression models (linear, exponential, and polynomial) showed a similar AdjR2. The polynomial (2nd order) fitting explains about the 78% of the total variance and do not add any relevant clinical information to the age estimation process from the third molar. The standard deviation and relative error increase with the age. The I3M has its minimum in the younger group of studied individuals and its maximum in the oldest ones, indicating that its precision and reliability decrease with the age

A new formula for assessing skeletal age in growing infants and children by measuring carpals and epiphyses of radio and ulna

The aim of this study is to develop a specific formula for the purpose of assessing skeletal age in a sample of Italian growing infants and children by measuring carpals and epiphyses of radio and ulna. A sample of 332 X-rays of left hand-wrist bones (130 boys and 202 girls), aged between 1 and 16 years, was analyzed retrospectively. Analysis of covariance (ANCOVA) was applied to study how sex affects the growth of the ratio Bo/Ca in the boys and girls groups. The regression model, describing age as a linear function of sex and the Bo/Ca ratio for the new Italian sample, yielded the following formula: Age = -1.7702 + 1.0088 g + 14.8166 (Bo/Ca). This model explained 83.5% of total variance (R2 = 0.835). The median of the absolute values of residuals (observed age minus predicted age) was -0.38, with a quartile deviation of 2.01 and a standard error of estimate of 1.54. A second sample test of 204 Italian children (108 girls and 96 boys), aged between 1 and 16 years, was used to evaluate the accuracy of the specific regression model. A sample paired t-test was used to analyze the mean differences between the skeletal and chronological age. The mean error for girls is 0.00 and the estimated age is slightly underestimated in boys with a mean error of -0.30 years. The standard deviations are 0.70 years for girls and 0.78 years for boys. The obtained results indicate that there is a high relationship between estimated and chronological ages

The Fourth Cervical Vertebra Anterior and Posterior Body Height Projections (Vba) for the Assessment of Pubertal Growth Spurt

This paper aims to propose a statistical model to assess pubertal growth spurt using the ratio of the anterior height projection to the posterior (Vba) of the fourth cervical vertebra body (C4) on cephalograms and to calculate the residual proportion of skeletal maturation and the time for the pubertal growth spurt to end for a given Vba. A sample of 538 cephalograms from healthy-living children aged between 5 and 15 years was analyzed. A segmented regression model was used to explain the different Vba stages relative to the pubertal growth spurt. In addition, the time to achieve skeletal maturation was evaluated for a given Vba between the beginning (Vba1) and the end (Vba2) of the pubertal growth spurt. A longitudinal sample of 25 males and 25 females was analyzed to validate the proposed method. The values of Vba corresponding to higher pubertal development rate ranged from Vba1 = 0.677 (95%CI, 0.644–0.711) to Vba2 = 0.966 (95%CI, 0.905–1.028) and from Vba1 = 0.669 (95%CI, 0.645–0.693) to Vba2 = 1.073 (95%CI, 1.044–1.101) in males and females, respectively. The validation process results showed that our model did not produce any incorrect forecasts. The proposed method estimates the beginning and the end of the pubertal growth spurt together with the residual proportion of skeletal maturation for a given Vba

The Fourth Cervical Vertebra Anterior and Posterior Body Height Projections (Vba) for the Assessment of Pubertal Growth Spurt

This paper aims to propose a statistical model to assess pubertal growth spurt using the ratio of the anterior height projection to the posterior (Vba) of the fourth cervical vertebra body (C4) on cephalograms and to calculate the residual proportion of skeletal maturation and the time for the pubertal growth spurt to end for a given Vba. A sample of 538 cephalograms from healthy-living children aged between 5 and 15 years was analyzed. A segmented regression model was used to explain the different Vba stages relative to the pubertal growth spurt. In addition, the time to achieve skeletal maturation was evaluated for a given Vba between the beginning (Vba1) and the end (Vba2) of the pubertal growth spurt. A longitudinal sample of 25 males and 25 females was analyzed to validate the proposed method. The values of Vba corresponding to higher pubertal development rate ranged from Vba1 = 0.677 (95%CI, 0.644–0.711) to Vba2 = 0.966 (95%CI, 0.905–1.028) and from Vba1 = 0.669 (95%CI, 0.645–0.693) to Vba2 = 1.073 (95%CI, 1.044–1.101) in males and females, respectively. The validation process results showed that our model did not produce any incorrect forecasts. The proposed method estimates the beginning and the end of the pubertal growth spurt together with the residual proportion of skeletal maturation for a given Vba