Objective To study the accuracy of Nolla method for age estimation of Northern Chinese Han children aged between 5.00 and 14.99 years based on original transformation tables and multiple regression model. Methods A total of 2 000 orthopantomographs （OPGs） were collected from the Hospital of Stomatology, Xi'an Jiaotong University, including 1 000 males and 1 000 females. Development stage of 7 left mandibular permanent teeth （except third molars） was assessed based on Nolla method, then age estimation was conducted through transformation tables and multiple regression model, respectively. Firstly, the development stage results of 7 permanent teeth were added up and the estimated age was obtained through the original transformation tables. Secondly, 80% of the samples （80 males and 80 females in each age group） were randomly selected from 2 000 OPGs as the train set. The chronological age of the selected patients was taken as the dependent variable, while gender and the development stage results of 7 permanent teeth were taken as the independent variable to establish multiple regression model. The remaining 20% of the samples were substituted into the model as the test set, to verify the accuracy of age estimation by multiple regression model. Results Mean chronological ages of males and females were 10.03±0.09 years and 10.01±0.09 years, respectively. The age estimated by original transformation tables showed an overestimation for males （0.18 years on average） and an underestimation for females （0.02 years on average）, with mean absolute error （MAE） of 0.94 years and 0.97 years, respectively. While the results by multiple regression model showed that males were overestimated by 0.06 years on average and females were underestimated by 0.02 years on average. The MAE was 0.66 years and 0.77 years, respectively. Conclusion The Nolla method is suitable for age estimation of Northern Chinese Han children. Compared with the original transformation tables method, the multiple regression model is more accurate for age estimation.
Adolescent ; Age Determination by Teeth ; Asian People ; Child ; Child, Preschool ; China ; Female ; Humans ; Male ; Molar, Third ; Radiography, Panoramic

Objective To establish a linear relationship between age and the development process of the mandibular second, third molars in a northern Chinese population and test its accuracy in inferring whether the subject is over 18 years old. Methods The orthopantograms （OPGs） of 960 northern Chinese people aged between 10.00 to 25.99 years were selected. The gender, birth date, and date of the orthopantograms of each sample were recorded. The development stages of left mandibular second and third molars were divided with Demirjian method. The experimental group （760 individuals） constructed a Logistic regression equation to infer whether the subject is over 18 years old. The validation group （200 individuals） tested the accuracy of the equation. Results When only using third molar, the formula obtained for inferring whether the subject's age is over 18 years is： logit P₁=-18.276+0.494 x₁+2.953 x₃. When combining the second and the third molars, the formula is： logit P₂=-21.045+3.177 x₁+0.619 x₂+2.088 x₃. （x₁ stands for gender, male is marked as 1 and female is marked as 2; x₂ and x₃ stand for the development stage of second molar and third molar, respectively）. The accuracy rates of this equation in estimating whether ages of subjects from the validation group were over 18 years old for males and females were 88.0%-92.0% and 85.0%-88.0%, respectively. Conclusion The age estimation formulas based on the development of mandibular second and third molars have important value in judging whether the individual is over 18 years old. Meanwhile, the accuracy of age estimation can be improved by combining the development of second and third molars together.
Adolescent ; Age Determination by Teeth ; Asian People ; Female ; Humans ; Logistic Models ; Male ; Molar, Third ; Radiography, Panoramic ; Young Adult

Objective To apply Demirjian's and Cameriere's method for dental age estimation of adolescents from Hunan Han nationality, and compare the accuracy of the two methods. Methods A total of 480 orthopantomograms of?8-16 year?old adolescents from Hunan Han nationality?with no special diseases and good nutritional status were collected?by Xiangya Stomatological Hospital of Central South University from January, 2016 to July, 2017, among them 236 males and 244 females. The dental age of each adolescent was determined by Demirjian's method and Cameriere's method, respectively, and the paired t-test of the estimated dental age and the chronological age determined by the two methods was conducted by SPSS 20.0 software to compare the difference between estimated dental age and chronological age. Results Mean chronological age of males and females was 11.91 and 11.88 years, respectively. The estimated dental age determined by Demirjian's method showed an underestimate of chronological age by an average of 0.11 years （males） and 0.15 years （females）, while the estimated dental age determined by Cameriere's method showed an underestimate of chronological age by an average of 0.83 years （males） and 0.72 years （females）. Conclusion Demirjian's method is more accurate than Cameriere's method in dental age estimation of adolescents from Hunan Han nationality, therefore more suitable for dental age estimation of adolescents in this region.
Adolescent ; Age Determination by Teeth ; Asian People ; Child ; China ; Ethnicity ; Female ; Forensic Dentistry ; Humans ; Male ; Radiography, Panoramic ; Reproducibility of Results

In recent years, individual age estimation has gained increasing attention in forensic practice. Common age estimation methods mainly use developments of teeth and bones. Compared with bones, teeth are stronger and are highly resistant to external factors, therefore plays an important role in age estimation. Demirjian's method is one of the most commonly used methods to evaluate dental age and has been widely used in many countries. In this paper, the accuracy of its application in different populations is reviewed. It is found that compared with the chronological ages, most of the estimated ages are overestimated. By combining research results of many scholars and by analyzing, it can be assumed that this situation may be related with race, region, sex, etc.
Age Determination by Teeth ; Forensic Dentistry/standards* ; Research/trends* ; Tooth/anatomy & histology*

The teeth are the hardest structures in the body and can be a biomarker of aging. The aging process and degenerative changes in the teeth are helpful for estimation of age in adults. One of the best-known features of dental aging is a reduction in the size of the pulp chamber as a result of secondary deposition of dentin. In this study, we developed new regression models to estimate chronological age in Korean adults using the mandibular first molars to examine the relationship between age and pulp cavity size on intraoral radiographs. Intraoral periapical digital radiographs of the mandibular first molars were collected from 243 patients (147 male, 96 female) of known age. The radiographic images were analyzed by using the Adobe Photoshop CS5 image editing program. The pulp chamber height ratio (PCHR), pulp chamber width ratio (PCWR) were calculated and found to have a significant negative correlation with age. The correlation was consistently higher for PCHR than for PCWR. The strongest correlation was found for PCHR in female patients (r=−0.824). Multiple regression models were derived using the PCHR and PCWR. The determination coefficients (R²) of the models ranged from 0.660 to 0.730. Our results indicate that the measurement of pulp chamber height and width in the mandibular first molar is a practical, simple and reliable method for estimation of age in Korean adults.
Adult ; Age Determination by Teeth ; Aging ; Dental Pulp Cavity ; Dentin ; Female ; Humans ; Korea ; Male ; Methods ; Molar ; Radiography ; Tooth

There have been many radiographic studies on age estimation that evaluate reduction in size of dental pulp cavity with secondary dentin formation. The Paewinsky method reported high accuracy in estimating ages by measuring the width of the pulp cavity in panoramic radiographs. The aim of this study was to evaluate the application of the Paewinsky method to digital periapical radiographs. This study was conducted on 103 cases that reported to the Section of Human Identification of the National Forensic Service. The age was calculated by applying the Paewinsky method that measures the root and pulp canal width at three points in a tooth. The estimation results were compared with those calculated by the Johanson method. When the Paewinsky models were applied to digital periapical radiographs, the errors were significantly greater as compared to the original study. The errors of the maxillary second premolar and mandibular lateral incisor were greater than those of the maxillary central incisor, lateral incisor, mandibular canine, and first premolar. Furthermore, errors of the age estimation models in level C were greater than those in levels A and B. This study could be a reference for the application of the Paewinsky method to digital periapical radiographs.
Age Determination by Teeth ; Bicuspid ; Dental Pulp Cavity ; Dentin, Secondary ; Forensic Anthropology ; Incisor ; Methods ; Radiography, Dental ; Tooth

Age estimation is a hot and difficult issue in forensic practice. Teeth are the most solid organs in human body and can be kept in vitro for a long time. With age, the secondary dentin gradually generates and the volume of pulp cavity constantly decreases. Therefore, forensic dentists proposed that age-related changes of dentin-pulp complex could be used to estimate age, which has been widely applied in forensic practice over the years. Due to the development of imaging technology, a variety of methods have been advocated by forensic dentists to detect the age-related changes of dentin-pulp complex for age estimation. However, different methods have their own advantages and limitations, forensic scientists should combine the use of different methods for improving the accuracy of age estimation according to the actual situation. This paper reviews current research of age estimation based on dentin-pulp complex, so as to provide reference for related research.
Age Determination by Teeth ; Dental Pulp ; Dentin ; Forensic Dentistry/methods* ; Humans

Age estimation is important in the practice of forensic science to establish the identity of human remains, as well as with living persons. Particularly in Korea, age estimation in adults has been increase in the demand for incorrect birth records in order to be entitled to civil liability, social benefits, employment. The reduction of pulp cavity size as a result of secondary dentin deposit with increasing age could be used to estimate age. This regressive change can be analyzed using radiological techniques; thus, a variety of methods for dental age estimation based on this approach have been proposed. The purpose of this study is to evaluate the concurrence between the Drusini's method and the Jeon's method using the mandibular first molar on orthopantomographs (OPGs) in Korean adults. A total of 232 OPGs (91 females and 141 males) of Korean individuals with ages ranging from 20 to 69 years were analyzed using Drusini's method and Jeon's method. Our results revealed that the correlation of the two methods with age was statistically significant (r=0.501). Both Drusini's method and Jeon's method showed significant correlation with chronological age, and Jeon's method showed a greater correlation with chronological age (r=0.738) than Drusini's method (r=0.586). The mean absolute error was 7.99 years for Jeon's method and 9.79 years for Drusini's method. Our results demonstrate that Jeon's method using the mandibular first molar on OPGs is a practical and suitable method for age estimation in Korean adults.
Adult* ; Age Determination by Teeth ; Birth Certificates ; Dentin ; Dentin, Secondary ; Employment ; Female ; Forensic Sciences ; Humans ; Korea ; Methods* ; Molar* ; Radiography

Forensic dentistry is an interdiscipline of forensic medicine and stomatology, which provides legal information by collecting, testing and assessing the dental evidence scientifically. In this review, the present application of forensic dentistry has been described, such as the estimation of age, sex, species, occupation and living habit, as well as the identification of individual, domestic violence or abuse, which aims to enrich and improve forensic dentistry for making it be more useful in forensic medicine even in juridical practice.
Age Determination by Teeth ; Forensic Anthropology ; Forensic Dentistry/methods* ; Forensic Medicine ; Humans ; Tooth

PURPOSE: This study assessed the accuracy of age estimates produced by a regression equation derived from lower third molar development in a Thai population. MATERIALS AND METHODS: The first part of this study relied on measurements taken from panoramic radiographs of 614 Thai patients aged from 9 to 20. The stage of lower left and right third molar development was observed in each radiograph and a modified Gat score was assigned. Linear regression on this data produced the following equation: Y=9.309+1.673 mG+0.303S (Y=age; mG=modified Gat score; S=sex). In the second part of this study, the predictive accuracy of this equation was evaluated using data from a second set of panoramic radiographs (539 Thai subjects, 9 to 24 years old). Each subject's age was estimated using the above equation and compared against age calculated from a provided date of birth. Estimated and known age data were analyzed using the Pearson correlation coefficient and descriptive statistics. RESULTS: Ages estimated from lower left and lower right third molar development stage were significantly correlated with the known ages (r=0.818, 0.808, respectively, P≤0.01). 50% of age estimates in the second part of the study fell within a range of error of ±1 year, while 75% fell within a range of error of ±2 years. The study found that the equation tends to estimate age accurately when individuals are 9 to 20 years of age. CONCLUSION: The equation can be used for age estimation for Thai populations when the individuals are 9 to 20 years of age.
Age Determination by Teeth ; Asian Continental Ancestry Group* ; Forensic Dentistry ; Humans ; Linear Models ; Molar, Third* ; Parturition ; Radiography, Panoramic