Dental maturity curves in Finnish children: Demirjian's method revisited and polynomial functions for age estimation

Dental maturity was studied from 2213 dental panoramic radiographs of healthy ethnic Finns from southern Finland, aged between 2 and 19 years. The aim was to provide new Finnish maturity tables and curves and to compare the efficiency of Demirjian's method when differently weighted scores and polynomial regressions are used. The inter-ethnic variations lead us to calculate specific Finnish weighted scores. Demirjian's method gives maturity score as a function of age and seems better adapted for clinicians because, in their case, the maturity score is unknown. Polynomial functions give age as a function of maturity score and are statically adapted for age estimation studies. Finnish dental maturity tables and development curves are given for Demirjian's method and for polynomial functions. Sexual dimorphism is established for the same weighted score for girls and boys, and girls present a greater maturity than boys for all of age groups. Polynomial functions are highly reliable (0.19% of misclassifies) and the percentile method, using Finnish weighted scores, is very accurate (+/- 1.95 years on average, between 2 and 18 years of age). This suggests that polynomial functions are most useful in forensic sciences, while Demirjian's method is most useful for dental health clinicians.     

Comparison of dental maturity in children of different ethnic origins: international maturity curves for clinicians

Dental maturity was studied with 9577 dental panoramic tomograms of healthy subjects from 8 countries, aged between 2 and 25 years of age. Demirjian's method based on 7 teeth was used for determining dental maturity scores, establishing gender-specific tables of maturity scores and development graphs. The aim of this study was to give dental maturity standards when the ethnic origin is unknown and to compare the efficiency and applicability of this method to forensic sciences and dental clinicians. The second aim was to compare the dental maturity of these different populations. We noted an high efficiency for International Demirjian's method at 99% CI (0.85% of misclassified and a mean accuracy between 2 to 18 years +/- 2.15 years), which makes it useful for forensic purposes. Nevertheless, this international method is less accurate than Demirjian's method developed for a specific country, because of the inter-ethnic variability obtained by the addition of 8 countries in the dental database. There are inter-ethnic differences classified in three major groups. Australians have the fastest dental maturation and Koreans have the slowest.     

Reliability of the methods applied to assess age minority in living subjects around 18 years old. A survey on a Moroccan origin population

We present a review of a population of 114 immigrant Moroccan males for which an age estimation was requested. The subjects' real chronological age was confirmed by the Moroccan Embassy in Spain. The confirmed age range was between 13 and 25, with an average age of 18.1 years and a standard deviation of 2.03. The following tests were performed to arrive at the forensic estimation of age: general physical examination, carpus X-ray (Greulich and Pyle method) and dental orthopantomography to determine the degree of maturity of the third inferior molars (Demirjian's method). Carpus X-ray (skeletal age) was the most useful method, followed by Demirjian's method (dental age), as prediction factors of a chronological age of over or under 18. The combination of skeletal and dental age variables represented a significant improvement in the prediction of the chronological age of the subjects in this population, reducing the number of ethically unacceptable test errors to a minimum.     

Dental age assessment: the applicability of Demirjian method in eastern Turkish children

In the literature, little is known about the applicability of this method in Turkish children. The aim of this study was, therefore, to evaluate the reliability of Demirjian method of age estimation when used for eastern Turkish children. A retrospective study was performed on a sample of panoramic radiographs taken from 807 healthy eastern Turkish children. The stages of dental maturity of the mandibular left seven permanent teeth for each subject using the eight radiographic dental maturity stages demonstrated by Demirjian were evaluated. A paired t-test was used for statistical analysis. The mean difference between the chronological and dental ages ranged from 0.2 to 1.9 years in girls and from 0.4 to 1.3 years in boys. The differences between the chronological and dental ages were statistically significant in all age groups. The applicability of Demirjian method is not suitable for eastern Turkish population.     

应用Demirjian法进行法医学年龄推断的评价

目的对应用Demirjian法进行法医学年龄推断的准确度及可靠性进行初步评价。方法应用Demirjian法测定828名上海地区青少年(男279名,女549名,11～19周岁)的牙龄,比较所测牙龄和实际年龄的差异。结果在11～14岁年龄段Demirjian法测定的牙龄比实际年龄高估,在15～16岁年龄段低估,在17岁及17岁以上年龄段具有局限性。结论Demirjian法可以用于测定上海地区11～16岁年龄段青少年的牙龄,使用时需进行适当的修正。     

Age estimation of Korean children based on dental maturity

The aim of this study was to evaluate the relationship between age and dental maturity and to establish the standard database of dental maturity based on the Demirjian's stages, which can be used for the age estimation of Korean children. For this purpose, dental maturity was measured by the Demirjian's stages on a randomly selected sample of panoramic radiographs taken from 2706 patients between 1 and 20 years of age and analyzed by multiple linear regression analysis based on the method of least squares. The results showed that, except for the third molars, the development of permanent teeth in Korean children was more advanced in females. The Demirjian's stage G of the second molar appeared last in both male and female subjects by age 18, showing 95th percentile at age in the male and female subjects between 16.7-17.4 years and 17.1-17.3 years, respectively. Coefficients of determination (r(2)) of the Demirjian's stages relative to age in regression analysis were 0.9721 in male and 0.9740 in female subjects. The standard error was 0.63 years in male and 0.62 years in female subjects. The estimated age according to regression analysis was within +/-1.0 year of the actual age in 92.0% of male and 92.5% of female subjects. Collectively, the data of the present study can be used as a reference for dental maturity and a standard for age estimation of Korean children.     

Odontological Approach to Sexual Dimorphism in Southeastern France

Abstract: The aim of this study was to establish a prediction formula to allow for the determination of sex among the southeastern French population using dental measurements. The sample consisted of 105 individuals (57 males and 48 females, aged between 18 and 25 years). Dental measurements were calculated using Euclidean distances, in three‐dimensional space, from point coordinates obtained by a Microscribe. A multiple logistic regression analysis was performed to establish the prediction formula. Among 12 selected dental distances, a stepwise logistic regression analysis highlighted the two most significant discriminate predictors of sex: one located at the mandible and the other at the maxilla. A cutpoint was proposed to prediction of true sex. The prediction formula was then tested on a validation sample (20 males and 34 females, aged between 18 and 62 years and with a history of orthodontics or restorative care) to evaluate the accuracy of the method.     

Dental Age Assessment in Children: A Comparison of Four Methods in a Recent French Population

The aim of this study was to analyze the accuracy and the reliability of four methods of dental age estimation (Demirjian, Willems I, Willems II, and Chaillet standards) in a French population. Orthopantomograms of 743 children aged between 4 and 15 years were used. The Demirjian standards gave a consistent overestimation of dental age compared with chronological age (+0.45 and +0.46 years for girls and boys, respectively). We found that three modified methods were more accurate for both sexes than Demirjian's method: the Willems I method appeared to be more suitable when the sex and ethnicity are both known (?0.09 and +0.14 years for girls and boys, respectively); the Willems II method was more accurate for children of unknown sex (mean difference = 0.00 years), and the Chaillet method was found to be more accurate than the Demirjian method, but less accurate than the Willems I method (?0.59 and ?0.18 years for girls and boys, respectively).     

Estimating age in Maori, Pacific Island, and European children from New Zealand

The islands of New Zealand are populated by persons of European, Maori, and Pacific Island extraction. The purpose of this research is to quantify the levels of dental maturation of each of these three populations, in order to obtain data that will be useful in forensic identification and age estimation. The sample consisted of 1383 orthopantomographs (660 males, 723 females) of 477 Maori, 762 European, and 144 Pacific Island children between the ages of 3 and 14 years. Each radiograph was digitized and the stages of mineralization of the seven left mandibular permanent teeth were assessed using the eight stages described by Demirjian. Values for 1, 3, 5, 50, 95, 97, and 99% confidence intervals are listed for each maturity score. Intra-observer reliability was evaluated using Bland-Altman's method on data from re-scoring one out of every 20 radiographs and standard dental maturation curves were constructed for the three populations by means of a quantile regression method. Despite the fact that quantile regression analysis showed that across the age group investigated there were differences between boys and girls, knowledge of the sex does not increase the accuracy of the age estimate, simply because the magnitude of the error of age estimation is greater than the difference between the sexes. Our analysis also shows that population divergence is most marked after the age of 9 years, with a peak difference seen at age 10.     

To evaluate the utility of smaller sample sizes when assessing dental maturity curves for forensic age estimation

Dental maturation and chronological age estimation were determined from 144 healthy Western Australian individuals aged 3.6-14.5 years. The results were compared with Farah et al.'s previous study which comprised a larger heterogeneous sample of Western Australian individuals (n = 1450). Orthopantomograms were analyzed with the application of Demirjian and Goldstein's 4-tooth method based on eight stages of dental mineralization. Analysis of variance revealed no significant differences in dental maturity scores in each age group among the males in both studies; similar results were seen in the females. Paired t-tests showed no statistical significance overall between chronological and estimated ages for the males in our sample (p = 0.181), whereas the females showed significant differences (p < 0.001). Our results show that smaller samples may be used when assessing dental maturity curves for forensic age estimation.     

Excretion of Delta9-tetrahydrocannabinol in sweat

The aims of this study were: first, to determine the accuracy of the Cameriere method for assessing chronological age in children based on the relationship between age and measurement of open apices in teeth and, second, to compare the accuracy of this method with the widely used Demirjian et al. method and with the method proposed by Willems et al. Orthopantomographs taken from white Italian, Spain and Croatian children (401 girls, 355 boys) aged between 5 and 15 years were analysed following the Cameriere, Demirjian and Willems methods. The difference between chronological and dental age was calculated for each individual and each method (residual). The accuracy of each method was assessed using the mean of the absolute values of the residuals (mean prediction error). Results showed that the Cameriere method slightly underestimated the real age of children. The median of the residuals was 0.081 years (interquartile range, IQR=0.668 years) for girls and 0.036 years for boys (interquartile range, IQR=0.732 years). The Willems method showed an overestimation of the real age of boys, with a median residual error of -0.247 years and an underestimation of the real age of girls (median residual error=0.073 years). Lastly, the Demirjian method overestimated the real age of both boys and girls, with a median residual error of -0.750 years for girls and -0.611 years for boys. The Cameriere method yielded a mean prediction error of 0.407 years for girls and 0.380 years for boys. Although the accuracy of this method was better for boys than for girls, the difference between the two mean prediction errors was not statistically significant (p=0.19). The Demirjian method was found to overestimate age for both boys and girls but the mean prediction error for girls was significantly greater than that for boys (p=0.024), and was significantly less accurate than the Cameriere method (p<0.001). The Willems method was better than that of Demirjian (p=0.0032), but was significantly less accurate than that of Cameriere (p<0.001).     

陕西省6～15岁汉族未成年人牙龄的研究

目的运用全口曲面断层影像技术,研究陕西省6-15岁汉族未成年人牙齿钙化规律,建立利用牙齿钙化程度推断陕西汉族6-15岁未成年人年龄的方法。方法按照中国汉族儿童及青少年牙齿钙化分级标准,对1997名（男934名,女1063名）陕西省6-15岁汉族未成年人的全口曲面断层影像中下颌恒牙钙化程度进行分级评分;将所得评分值及对应的年龄输入SPSS软件并进行统计分析,最终建立年龄推断的方程。结果下颌同名牙钙化评分值侧别间非参数检验结果 P〉0.05,而性别间非参数独立样本检验结果 P〈0.05;下颌左侧各颗恒牙钙化程度与年龄相关分析结果 r〉0.59;方程拟合优度检验所得校正决定系数均大于0.76,估计值标准误男性在0.85-1.05岁之间、女性在0.83-0.97岁之间。结论本研究建立的方法合理可靠,可用于陕西省汉族6-15岁未成年人年龄的推断。     

Developing permanent tooth length as an estimate of age.

Developing teeth are widely used to predict age in archaeology and forensic science. Regression equations of tooth length for age is a direct method, however, data for permanent teeth is incomplete. The aims of this study were: (a) to calculate regression equations predicting age from tooth length of all permanent teeth from birth to maturity, and (b) to evaluate the difference between radiographic and actual tooth length. The sample studied (N = 76, age range 0 to 19 years) was the Spitalfields juveniles of recorded age-at-death. Tooth length was measured from incisal tip to developing edge of crown or root of 354 dissected teeth. Data for upper and lower teeth were combined except for the lateral incisor. The least squares regression method was used to analyze the data for each tooth type; age being regressed against tooth length for prediction. For most tooth types, growth followed an S-shaped (polynomial) curve with initial fast growth and a further growth spurt around the time of mid root formation. No difference was found between radiographic and true tooth length. These regression equations provide an easy method of predicting age from any developing permanent tooth by measuring tooth length from isolated teeth or from unmagnified, undistorted radiographs.     

Third molar development according to chronological age in populations from Spanish and Magrebian origin

Spain is frequently the entrance country into the European Union for undocumented immigrants, especially those from the Magreb (Northern Africa). Forensic age estimates for these persons are difficult because systematic studies of dental maturity are lacking. Three different populations were analyzed to determine the pattern of development of third molars as a tool for age estimation in people of different ethnic and geographic origin. Orthopantomograms from two different populations of Spanish origin (Galicia in northwestern continental Spain, and Ceuta, a Spanish province in Northern Africa) were compared to radiographs of molars from a Magrebian population (Northern Africa) resident in Ceuta. Orthopantomograms were obtained from a private dental clinic (n=344) in Galicia and from the Public Oral Health Services (n=228) in Ceuta. We looked for differences in third molar mineralization (determined with the Demirjian scale) that might serve as age indicators (older versus younger than 18 years). Differences in maturation patterns were found between sexes and populations of origin. Mineralization of tooth 38 was more advanced in males than females among subjects 18 years of age and older in all three populations. Moreover, mineralization of tooth 38 in subjects aged 18 years and older was significantly slower in the Spanish-Galicia population than in the Magrebian-Ceuta population. We found no significant differences between Magrebian and Spanish individuals from Ceuta. We conclude that differences in tooth 38 mineralization may be related more with socio-geographical than ethnic origin (ancestry), and thus constitute evidence of the relevance of socio-geographic rather than genetic factors in third molar development. We used ROC analysis to determine the accuracy of the examiner's ability to correctly estimate age as younger or older than 18 years. The results suggest that Demirjian stage for tooth 38 can be considered a good indicator of age in all three populations.     

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.     

Validity of Demirjian's and modified Demirjian's methods in age estimation for Korean juveniles and adolescents

In estimating age of juveniles and adolescents, the teeth are employed primarily because of its low variability and less affection by endocrine and nutritional status in development. Demirjian established criteria for evaluating maturity of teeth and his method has been used throughout the world. However, several studies showed the inappropriateness of Demirjian's method on populations other than the one it is based on. Consequently some researchers modified Demirjian's method using data of several different populations. Demirjian himself also published a revised method to overcome other shortcomings of his original method. The aim of this study was to test the validity of Demirjian's and the modified methods (Demirjian's revised, Willems', Chaillet's and new Korean methods) for Korean juveniles and adolescents. 1483 digital orthopantomograms which consist of 754 males and 729 females in the age range of 3-16 years were collected. New age estimation method based on Korean population data was calculated. Dental age was estimated according to each method and the validity was evaluated using the differences between chronological and dental age. The inter- and intra-observer reliability was evaluated to be excellent. Statistically significant difference was observed between chronological and dental age in all the methods for both sexes except new Korean method for both sexes and Demirjian's revised method for males. However, when analyzing absolute and squared value of difference, Willems' method was found to be most accurate followed by new Korean method with slight difference for Korean population for both sexes. In conclusion, both Willems' method and new Korean method conducted by present study were proven to be suitable for Korean population.     

重庆地区汉族未成年人牙龄推断的研究

目的运用牙齿曲面断层影像技术,研究6周岁～15周岁重庆市未成年人牙齿钙化的规律,从而建立根据牙齿钙化程度推断年龄的方法。方法依据牙齿钙化分级标准对1321名（男性577名,女性744名）重庆市6周岁～15周岁未成年人牙齿曲面断层片上的牙齿钙化程度进行分级评分;将评分值与对应的性别和年龄分别输入SPSS13.0软件进行统计分析,最终建立推断年龄的方程。结果左右侧同名牙齿钙化程度无统计学差异（P〉0.05）,但性别间有统计学差异（P〈0.05）;下颌左右侧8颗牙齿的钙化程度与年龄相关系数均大于0.58;所建利用不同牙齿组合推断年龄的线性回归模型调整拟合优度均大于0.67,估计值标准误男性为0.95周岁～1.11周岁、女性为1.02周岁～1.12周岁。结论该方法可用于法庭科学领域中推断重庆市6周岁～15周岁未成年人活体以及尸体的年龄。     

Is the Assessment of Dental Age by the Nolla Method Valid for Eastern Turkish Children?

The aim of this study was to investigate whether or not the Nolla method is appropriate for Turkish children for the determination of the dental age (DA). A group of 719 children between the ages of 6 and 18 years were included in the study. DAs from orthopantograms by the Nolla method were estimated. The results obtained were compared with chronologic age (CA). Paired t and the Wilcoxon tests were performed. Both genders were underestimated in dental maturity when compared with the reference samples in total (-0.3 years) (p<0.01). The differences in girls were statistically significant in total and in all groups except for 7-7.9. The differences in boys between the CAs and DAs were not statistically significant in total and in all groups except for 7-7.9 and 8-8.9. Although the accuracy of this method was suitable for boys, according to our findings, it was not suitable for girls.