Radiological Evaluation of the Accuracy of Demirjian, Nolla, and Willems Methods for Dental Age Estimation in 3-17-Year-Old Iranian Children.

Background: The stage of tooth formation is one of the most reliable indicators for predicting a patient's developmental age by radiographs. This study compared the accuracy of three distinct dental age estimation methods (Demirjian, Nolla, and Willems) in children aged 3-17 in the northern Iranian population. Methods: This cross-sectional study examined panoramic radiographs of 434 children aged 3-17 from Mazandaran Province, Iran, who had teeth 31-37 present on the left mandible. This study employed the Demirjian, Nolla, and Willems methods to estimate the dental age of the sample and compare it with the chronological age. The data were analyzed using SPSS v16. A paired t-test was used to compare chronological and dental ages. The Pearson correlation was used to correlate the chronological and dental ages. The errors of different methods were compared using the Wilcoxon test. P values < 0.05 were considered significant for all tests except Wilcoxon. For Wilcoxon, a P value < 0.017 was considered significant. Results: The three methods presented differing mean estimated ages. The Demirjian method delivered the highest mean, and all three methods differed significantly when compared in pairs. The results showed that the Demirjian method overestimated chronological age by 0.25 years (P < 0.001) in girls and 0.09 years (P = 0.28) in boys. The Willems method underestimated chronological age by 0.05 years (P = 0.47) in girls and 0.12 years (P = 0.13) in boys. The Nolla method underestimated chronological age by 0.41 years (P < 0.001) in girls and 0.40 years (P < 0.001) in boys. The accuracy of each method varied with the patient's age. Conclusion: According to the findings, the Willems method outperformed the Demirjian method, and the Demirjian method exceeded the Nolla method for estimating dental age in Iranian children aged 3-17. Overall, the Demirjian method overestimated the age of the study population, whereas the other two underestimated it.

Assessment of permanent teeth development in children with multiple persistent primary teeth.

BACKGROUND: Persistent primary teeth (PPT) may occur due to various local factors, or it may develop due to general factors such as systemic diseases and syndromes. Since eruption and dental development are two different processes, it is important to investigate both processes to determine the actual cause of delayed tooth eruption. The study aimed to evaluate the dental development of a group of Turkish children with multiple PPT using the Willems dental age estimation method. STUDY DESIGN: Digital panoramic radiographs of children and adolescents aged between 9 and 15 years were retrieved, assessed and categorized. A total of 80 radiographs of patients with more than one PPT were selected and matched with children without PPT. Dental age was calculated using the method of Willems et al. All analyses were conducted using the SPSS statistical software. The statistical significance was set at 0.05. RESULTS: The permanent tooth development of children with multiple PPT could be delayed by 0.5-4 years compared to healthy ones. A strong positive correlation was found between the number of PPT and deviation for both females and males (p < 0.001). CONCLUSION: In conclusion, we found that permanent tooth development of children with multiple PPT could be delayed compared to healthy ones. In addition, as the number of PPT increased, the difference between chronological age and dental age also increased, especially in males.

Demirjian method and Willems method to study the dental age of adolescents in Shanghai before and after 10 years.

BACKGROUND: The aim of this study was to assess whether the difference in dental ages between 2009 to 2011 and 2021 is affected by environmental factors such as environmental pollution, floating population, and dietary habits. MATERIALS AND METHODS: Demirjian and Willems dental age estimation methods were conducted for a Han population of children aged 8 to 14 in Shanghai, China. A total of 1259 digital panoramic radiographs of children aged 8.00-14.99 were estimated. All digital panoramic radiographs were estimated using the Demirjian and Willems methods. Data collected in 2009 to 2011 and 2021 were statistically analysed by paired t-tests. RESULTS: The results show that the Demirjian method overestimates 2009 to 2011 and underestimates 2021 the children's chronological age. When using the Willems method, the age of males was overestimated and the age of females was underestimated from 2009 to 2011, and it was underestimated for both genders in 2021. CONCLUSIONS: In conclusion, the difference in dental ages between 2009 to 2011 and 2021 was statistically significant. Factors such as environment and dietary habits have been found to be affected by dental development. However, there are disputes among some researchers about the exact factors, so it is suggested to further study the effects of environmental factors on tooth development.

Comparative assessment of the Willems dental age estimation methods: a Chinese population-based radiographic study.

BACKGROUND: The comparison of the two Willems dental age estimation methods (gender-specific (Willems I) and non-gender-specific (Willems II)) has not been fully investigated. Here we aimed to explore the applicability of the Willems dental age estimation in an Eastern Chinese population, which may cast light on the field of dental age estimation. METHODS: A total of 1211 oral panoramic radiographs (582 boys and 629 girls) of the Chinese Han population aged 11-16 years old were collected. Dental ages (DAs) were calculated using the Willems method. Statistical significance was set at a p-value < 0.05. Age differences between chronological age (CA) and dental age were analyzed by paired t-tests and mean absolute error (MAE). RESULTS: The differences between CA and DA determined by the Willems I method were + 0.44 and + 0.09 years for boys and girls, respectively. When using the Willems II method, these differences were + 0.57 and - 0.09. The MAEs of the Willems I method between DA and CA were 0.95 and 1.00 years in boys and girls, respectively. For Willems II, MAEs were 1.02 and 1.00 years in boys and girls. CONCLUSIONS: This study showed that the Willems I method was more accurate than the Willems II method in the boys' group for predicting age from a whole scale. In comparison, Willems II is more competitive in the girls' group. Neither method may be satisfactory for 11-to-16-year-old teenagers in Eastern China.

The Application of Artificial-Intelligence-Assisted Dental Age Assessment in Children with Growth Delay.

BACKGROUND: This study aimed to reveal the efficacy of the artificial intelligence (AI)-assisted dental age (DA) assessment in identifying the characteristics of growth delay (GD) in children. METHODS: The panoramic films matching the inclusion criteria were collected for the AI model training to establish the population-based DA standard. Subsequently, the DA of the validation dataset of the healthy children and the images of the GD children were assessed by both the conventional methods and the AI-assisted standards. The efficacy of all the studied modalities was compared by the paired sample t-test. RESULTS: The AI-assisted standards can provide much more accurate chronological age (CA) predictions with mean errors of less than 0.05 years, while the traditional methods presented overestimated results in both genders. For the GD children, the convolutional neural network (CNN) revealed the delayed DA in GD children of both genders, while the machine learning models presented so only in the GD boys. CONCLUSION: The AI-assisted DA assessments help overcome the long-standing populational limitation observed in traditional methods. The image feature extraction of the CNN models provided the best efficacy to reveal the nature of delayed DA in GD children of both genders.

Comperative evaluation of Nolla, Willems and Cameriere methods for age estimation of Turkish children in the Central Black Sea Region: A preliminary study.

PURPOSE: Since dental age estimation methods' accuracy and reliability levels differ in each society, the method should be appropriate for societies. This study aims to evaluate the applicability of Nolla, Willems, and Cameriere methods to Turkish children in the Central Black Sea Region. MATERIAL AND METHOD: This study was conducted based on the panoramic radiographs of 400 children between the ages of 6-14 years admitted to Tokat Gaziosmanpasa University Faculty of Dentistry, Department of Pediatric Dentistry for examination between 2016 and 2020. Nolla, Willems, and Cameriere methods estimated dental age on the selected panoramic radiographs. While 14 teeth in the left mandible and maxilla were evaluated for Nolla method, seven teeth in the left mandible were evaluated for Willems and Cameriere methods. Data were analyzed using IBM SPSS V23. The Pearson correlation coefficient was used to analyze the relationship between the chronological age (CA) and dental age (DA), and the paired sample t-test was used to analyze the difference. RESULTS: A statistically significant difference was found between CA-Nolla dental age (p = 0.002), CA-Willems dental age (p < 0.001), and CA-Cameriere dental age (p = 0.033) in boys. The mean differences between dental age and chronological age in boys were -0.24 years in the Nolla method, +0.49 years in Willems method, and -0.17 years in the Cameriere method. A statistically significant difference was found between CA-Nolla dental age (p = 0.001) and CA-Willems dental age (p < 0.001) in girls. The mean differences between dental age and chronological age in girls were -0.27 years in the Nolla method, +0.76 years in the Willems method, and -0.1 years in the Cameriere method. CONCLUSION: In this study method providing closest estimation for chronological age among children aged 6-14.99 that were examined in Central Black Sea Region, was the Cameriere method in both girls (79.9%) and boys (80.6%), followed by Nolla method and Willems method, respectively.

Dental age estimation with fewer than mandibular seven teeth: An accuracy study of Bedek models in Turkish children.

OBJECTIVES: One or more missing teeth, such as hypodontia, make it difficult to obtain accurate results in age estimation methods. This paper aims to test the accuracy of the models developed by Bedek et al. that can estimate age with fewer than seven teeth for Turkish children. MATERIALS AND METHODS: Panoramic radiographs of 1118 children (540 girls and 578 boys) aged between 6 and 16 years were evaluated using the Willems method and Bedek models for the entire sample and for different ages and sexes. Differences between dental age (DA) and chronological age (CA) calculated for all methods for each sex and all age groups were analyzed the paired sample t-test and Wilcoxon signed rank test. The accuracy of the DA estimation methods was determined by the proximity of DA to CA by calculating mean absolute error (MAE). RESULTS: While all Bedek models underestimated CA by 0.2 to 0.1 years, the Willems method overestimated CA by 0.3 years. DA-CA difference in the total sample and girls was statistically significant in all methods. In the total sample, the seven- and four-teeth models had the lowest MAE, while the one-tooth model had the highest MAE. CONCLUSIONS: Seven- and four-teeth models were the most suitable for age estimation, and all models except the one-tooth model were found to be more accurate than the Willems method in northwestern Turkish children. CLINICAL RELEVANCE: Especially in children with hypodontia, it may be possible to estimate DA with the use of Bedek models.

Estimation of dental age using Willems method and comparing it with Demirjian's method in 7-14-year-old children of Uttarakhand.

Age is one of the essential factors, which plays an important role in every aspect of life. Age is estimated on the basis of chronological age, bone age, dental age, mental age and others. This study represents the objective of an ideal age estimation technique to arrive at an age as close to the chronological age as possible. Aim: The aim of this comparative study was to estimate the dental age using Willems method by assessing the developmental stages of left seven permanent mandibular teeth in 7-14 years of age groups with the help of digital orthopantomogram and comparing it with Demirjian's method to conclude which method was more appropriate and better in Indian population of Uttarakhand region. Materials and Methods: A total of 100 digital orthopantomogram films of patients in the age group of 7-14 years was collected over the study period of 3 years from July 2014 to January 2017 and was equally distributed by convenience sampling. Group I included 50 boys and Group II included 50 girls aging 7-14 years of age (as permanent 7 teeth in the 3rd quadrant were to be assessed and scored according to the Demirjian's table, the 7-14 age group was selected). The date of birth of the subject was documented against their allocated identification number. Dental age according to Willem's method was calculated using Willem's table and Demirjian and Goldstein's table scores were used to calculate dental age by Demirjian's method. Results: Willems method was more accurate and better than Demirjian's method as it showed less mean percentage error, i.e., 0.34% as compared to 15.94% obtained from Demirjian's method in Group II and 2.19% as compared to 8.05% obtained from Demirjian's method in Group I. Conclusion: The results suggested that Willems method of dental age estimation was an effective method of age estimation and was better and more accurate than Demirjian's method.

Dental age estimation in children that have undergone antineoplastic treatment.

OBJECTIVE: Even though many studies have been performed to estimate DA in general population, limited research has been performed concerning medical compromised populations such as childhood cancer survivors. The aims of this case-control study were (a) to estimate dental age in a population of children that have undergone antineoplastic treatment with three different methods and (b) to compare it with the estimates from healthy subjects (control group). MATERIALS AND METHODS: Seventy-three oncology patients and equal number of healthy control subjects from the Pediatric dentistry Department had their dental age estimated through recent orthopantograms using Dermijian's, Willems' and London Atlas methods. All OPGs randomly assessed by two calibrated observers. Mean age difference was calculated. Intraclass Correlation Coefficient was used to assess intra-observer reliability and the Concordance Correlation Coefficient used to assess inter-observer reliability. RESULTS: Concerning the CCS group 35 subjects (48%) were males and 38 (52%) were females, with an overall mean chronological age 10.95 years, ranging between 5.37 and 15.83 years. Intra- and inter-examiner reliability was exceptional for all methods. Mean DA differences in both groups and were not statistically sinificant regardless of the method used. The marginally lower values when males and females were investigated separately is basically due to the corresponding reduction of the sample size. CONCLUSION: An overestimation of DA observed in both groups by all methods was not significant. All three methods produced highly accurate comparable results when it comes to estimate the actual chronological age in both groups (CCS and control subjects) regardless of gender.

Application of Willems Method as an Age Estimator in Early Adolescents of Bangalore Population.

INTRODUCTION: Dental age (DA) assessment is a reliable method for chronological age (CA) estimation used for criminal, forensic, and anthropologic purposes. Age estimation also provides valuable information when the birth date is unavailable, as in case of migrants. Furthermore, the CA of living people is important for employment and marriage purpose. OBJECTIVES: The aim of the present study is to check the reliability of the Willems method in the population of Bangalore. MATERIALS AND METHODS: The study was conducted on 205 (109 boys and 96 girls) participants by their radiographic records in the department of forensic odontology using modified Demirjian's method by Willem et al. RESULTS: A total of 205 subjects were selected for the study, among which 109 (53.2%) were boys and 96 (46.8%) were girls. The mean CA was 12.23 ± 1.75 and the mean DA was 12.20 ± 1.99. Willems method seems to be reliable in estimating DA in Bangalore populations. CONCLUSION: This study showed that the Willems method gave near precise estimation of the CA.

Dental age and skeletal maturity assessment in patients with cerebral palsy.

The aims of this study were to calculate the estimated dental age and the degree of skeletal maturity in patients with cerebral palsy and control patients (i.e., without a diagnosis of cerebral palsy) and to compare the findings with the chronological age of patients in both study groups. In this cross-sectional study, the European formula and the Willems method were used to estimate the dental age of 52 patients with cerebral palsy and 104 control patients, all aged between 7 and 15 years. For all patients, their estimated dental age was compared with their chronological age. The degree of skeletal maturity of 35 patients with cerebral palsy and 104 control patients was estimated according to Baccetti's method. There was no statistically significant difference in the deviation of the estimated dental age from the chronological age between patients with cerebral palsy and control patients when the European formula or the Willems method was applied. No difference was found in the frequency of Baccetti's stages between patients with cerebral palsy and control patients in the same age category, for both sexes. To estimate dental age in patients with cerebral palsy, the European formula is preferable for orthodontic purposes and the Willems method is preferable for forensic purposes. Using Baccetti's method it was not possible to detect potential differences in skeletal maturity between patients with cerebral palsy and controls.

A modified dental age assessment method for 5- to 16-year-old eastern Chinese children.

OBJECTIVES: Age estimation is widely applied in the field of orthodontics, pediatric dentistry, and forensic science. Dental age estimation by the radiological method is frequently used because of its convenience and noninvasiveness. However, there are not enough suitable methods for eastern Chinese children. This study aimed to establish a modified formula for eastern Chinese children according to the Demirjian method and then compared the accuracy of the modified method with the Demirjian method and Willems method. MATERIALS AND METHODS: A total of 2367 dental panoramic radiographs from individuals aged 5-16 years of eastern China were collected as samples. Age estimation was conducted using the Demirjian and Willems methods. The polynomial curve fitting method was used to modify the Demirjian method to improve its application to the eastern Chinese children. The paired t test and accuracy ratio were used to compare the applicability of the modified methods with two commonly used methods. RESULTS: The mean chronological age (CA) of the subjects was 11.20 ± 3.29 years for boys and 10.99 ± 3.12 years for girls. The mean difference values between the CA and dental age (DA) (CA-DA) using the Demirjian and Willems methods were 0.73 and 0.7 for boys, respectively, and both 0.79 for girls. The modified method using the polynomial curve fitting presented a smaller underestimation compared with CA for both boys (0.04 years) and girls (0.09 years), which showed a high suitability to Chinese children to some extent. CONCLUSIONS: The Willems method was more accurate in estimating DA compared with the Demirjian method. However, the modified method was more accurate than the two methods; therefore, it can be used in eastern Chinese children. CLINICAL RELEVANCE: It was thought to be a non-invasive, convenient, and efficient method to connect DA and CA. By estimating dental age, pediatrist, and orthodontists can better understand the development of permanent teeth and provide a more accurate orthodontic treatment time and treatment plan to children patients.

Validating dental age estimation in Kenyan black children and adolescents using the Willems method.

PURPOSE: This study aimed to validate the Willems Belgian Caucasian (Willems BC) age estimation model in a Kenyan sample, to develop and validate a Kenyan-specific (Willems KB) age estimation model and to compare the age prediction performances of both models. METHODS: Panoramic radiographs of 1038 (523 female, 515 male) Kenyan children without missing permanent teeth and without all permanent teeth fully developed (except third molars) were retrospectively selected. Tooth development of the seven lower-left permanent teeth was staged according to Demirjian et al. The Willems BC model, performed on a Belgian Caucasian sample and a constructed Kenyan-specific model (Willems KB) were validated on the Kenyan sample. Their age prediction performances were quantified and compared using the mean error (ME), mean absolute error (MAE) and root-mean-square error (RMSE). RESULTS: The ME with Willems BC method equalled zero. Hence, there was no systematic under- or overestimation of the age. For males and females separately, the ME with Willems BC was significantly different from zero, but negligible in magnitude (-0.04 and 0.04, respectively). Willems KB was found not to outperform Willems BC, since the MAE and RMSE were comparable (0.98 vs 0.97 and 1.31 vs 1.29, respectively). Although Willems BC resulted in a higher percentage of subjects with predicted age within a one-year difference of the true age (63.3% vs 60.4%, p=0.018), this cannot be considered as clinically relevant. CONCLUSION: There is no reason to use a country-specific (Willems KB) model in children from Kenya instead of the original Willems (BC) model.

Changes in the Sequence of Eruption of Permanent Teeth; Correlation between Chronological and Dental Age and Effects of Body Mass Index of 5-15-year-old Schoolchildren.

AIM: To determine the changes in the sequence and age of eruption of permanent teeth in 5-15-year-old schoolchildren, correlating their dental and chronological age. MATERIALS AND METHODS: A total of 1,477 schoolchildren aged between 5 years and 15 years were examined for the eruption timing, body mass index (BMI), and other oral findings. Dental age was calculated for 10% of the total sample using the Willem's method from their ortho-pento graphs (OPGs) and correlated with their chronological age. RESULTS: The maxillary teeth erupted earlier than mandibular teeth. Males were found to mature earlier than females. The sequence of eruption observed was: males (maxilla) 1-6-2-4-3-5-7 and (mandible) 1-6-2-3-4-5-7; females (maxilla) 6-1-2-4-3-5-7 and (mandible) 1-6-2-3-4-5-7. The chronological age and the dental age were found to be different in the age range of 9-10 years female; 10-11 years male; and in 13-14 years both male and female. Also when the dental age was correlated with the BMI, the dental age of obese children in 5-6 years and underweight children in 10-11 years were found to be far ahead of their actual chronological age. CONCLUSION: This study opens an expected door for a large sample size to be tested in various local populations with different ethnicity and race as there can be changing trend in the eruption pattern. CLINICAL SIGNIFICANCE: Changing trends in the sequence and age of eruption of the permanent teeth definitely need to be looked into. As this change, if firmly established in future, can help pedodontist in better planning of space management, interceptive as well as full-mouth orthodontic treatment which largely depends on this sequence being true in most of the cases. HOW TO CITE THIS ARTICLE: Khan AS, Nagar P, Singh P, et al. Changes in the Sequence of Eruption of Permanent Teeth; Correlation between Chronological and Dental Age and Effects of Body Mass Index of 5-15-year-old Schoolchildren. Int J Clin Pediatr Dent 2020;13(4):368-380.

Accuracy of the Demirjian, Willems and Nolla methods for dental age estimation in a northern Chinese population.

OBJECTIVE: The objective of the present study was to evaluate the accuracy of the Demirjian, Willems, and Nolla methods for dental age estimation on a sample of the northern Chinese population. DESIGN: The study consisted of 2000 panoramic radiographs (1000 boys and 1000 girls) with an age range between 5 and 14 years. The mean error and absolute mean error were calculated according to each method, and the accuracy was statistically analysed. RESULTS: The three methods used for Chinese subjects overestimated the dental age by 1.16, 0.50, and 0.07 years. The absolute mean error was largest in most age groups for the Demirjian method, which was considered inaccurate in age estimation for teenagers, and it was more than 1.00 years for only several age groups for the Willems method and only girls aged 14 years for the Nolla method. The mean error and absolute mean error were lowest for the Nolla method and highest for the Demirjian method. CONCLUSIONS: Although the Demirjian method is frequently used in Chinese subjects for legal and medical purposes, the Willems and Nolla methods were more reliable than the Demirjian method. Among the three methods, the accuracy in the northern Chinese subjects was highest for the Nolla method. Therefore, it is recommended to evaluate the accuracy of different methods before assessing the age in specific populations.

Accuracy assessment of dental age estimation with the Willems, Demirjian and Nolla methods in Spanish children: Comparative cross-sectional study.

BACKGROUND: The objective of this study was to evaluate and compare the validity and accuracy of the Willems, Demirjian and Nolla methods in predicting chronological age in a Spanish ethnicity population. METHODS: A sample of 604 orthopantomographs of Spanish children aged 4 to 13 years was evaluated by two independent evaluators. Descriptive statistics were applied to calculate the chronological age and dental age, presenting the mean and standard deviation. The difference between dental age and chronological age was calculated for each method. A positive result indicated an overestimation and a negative figure indicated an underestimation. The Wilcoxon test for paired data and Spearman's correlation coefficient were applied by age groups and sex to compare the chronological age and dental age of each method (that of Willems, Demirjian and Nolla). Statistical tests were performed at a 95% confidence level. RESULTS: The interexaminer agreement was 0.98 (p = 0.00), and the intraexaminer agreement was 0.99 (p = 0.00). The Willems method significantly overestimated the age of boys (0.35 years (0.93)) and girls (0.17 years (0.88)). The Demirjian method significantly overestimated the age of boys (0.68 years (0.95)) and girls (0.73 years (0.94)). The Nolla method significantly underestimated age in boys (0.44 years (0.93)) and girls (0.82 years (0.98)). CONCLUSIONS: In the Spanish population, the use of the Demirjian method for legal and medical purposes is frequent. This study reveals that the Willems method is more appropriate due to its greater precision in estimating dental age.

A Comparative Evaluation of Three Different Dental Age Estimation Methods in India: A Test of Ethnic Variability.

AIM: The present study aimed to evaluate and compare the applicability of Demirjian, Willems, and Haavikko methods of dental age estimation in southeastern (Dravidian ethnicity) and northwestern regions (Aryan ethnicity) of the Indian population. MATERIALS AND METHODS: The study includes the orthopantomographs (OPGs) of 303 individuals (173 males and 130 females) of age ranging from 5 to 14 years. The participants in the present research were evaluated under two study groups: group I: participants of the southeastern region and group II: participants of the northwestern region. Dental age was calculated using Demirjian, Willems, and Haavikko methods and compared with the chronologic age of each participant. The accuracy of dental age estimation methods was evaluated by mean absolute error. One-way analysis of variance (ANOVA) and Student's t tests were used to test the significant difference between the chronologic age and estimated dental ages. RESULTS: The Demirjian method showed overestimation, while Willems and Haavikko methods showed underestimation for boys and girls in both the ethnic groups of Indian population. The Willems method of dental age estimation showed comparatively more accurate and reliable results in both the ethnic groups of the Indian population. CONCLUSION: The dental age estimation by Demirjian, Willems, and Haavikko methods showed no significant variation between the different ethnicities of the Indian population. CLINICAL SIGNIFICANCE: The present research will be helpful in pedodontic, orthodontic, and forensic investigations for accurate and reliable dental age estimation in different parts of Indian population. HOW TO CITE THIS ARTICLE: Chaudhry K, Talwar M, Vanga NRV, et al. A Comparative Evaluation of Three Different Dental Age Estimation Methods in India: A Test of Ethnic Variability. Int J Clin Pediatr Dent 2020;13(1):16-20.

New model for dental age estimation: Willems method applied on fewer than seven mandibular teeth.

Willems method measures the developmental stages of the seven left permanent mandibular teeth and is frequently used for dental age estimation. The aim of this study was to test its accuracy on a large sample of the Croatian population and to develop new models for estimation based on one to seven mandibular teeth. The developmental stages were evaluated on the digital, standardized orthopantomograms of 1868 Croatian children aged 5 to 16. Univariate regression was used for age estimation based on one tooth and regression with forward and backward elimination for selection of the best combination on two to six teeth. Tested in parallel with Willems method, the accuracy of the new models was assessed within intervals of ± 0.5, ± 1, ± 1.5 and ± 2 years and shows the percentage of correct estimations. Using Willems method, the average overestimation was 0.41 years for boys and 0.22 years for girls. Newly developed models that use two to seven teeth proved to be significantly more accurate (p < 0.001). The accuracy of age estimation increases significantly with the number of teeth in a model. Predictably, within the interval ± 0.5 years, a model with three teeth has 3% fewer accurate age estimations than a model including seven teeth. In both theory and practice, Willems method has been considered suitable for age estimation among Croatian children. However, these newly developed models significantly surpass its accuracy. Models using two to seven teeth represent a simple, reliable, and accurate method for age estimation, even in cases with missing mandibular teeth.

Comparison of three methods to estimate dental age in children.

OBJECTIVES: In 1973, Demirjian and colleagues introduced a staging for tooth mineralization. Staging of the teeth of the left mandible generates a dental maturity score and an estimate of dental age. An update of this method was published in 2001 by Willems and colleagues. The London Atlas (2008) is another method used to assess dental age. This study compared the precision of these three methods for forensic age estimation. MATERIALS AND METHODS: A total of 500 panoramic images of 251 boys and 249 girls aged 6-16 years had dental maturity evaluated by the same observer using the London Atlas and the methods of Demirjian and Willems. Individuals with syndromes potentially affecting dental maturation were excluded. The three methods were compared with respect to their precision in estimating chronological age. RESULTS: Age estimates using Willems' method were significantly more precise than those obtained using Demirjian's method, while estimates obtained using the London Atlas method were comparable with both the others. The highest precision was obtained using the average of age estimates from Willems' method and the London Atlas. CONCLUSIONS: To estimate age in individuals suspected of being below 16 years of age, we suggest first applying the London Atlas then computing age from the Demirjian stages of particular teeth using Willems' method, and finally using the average age estimate of both methods. CLINICAL RELEVANCE: Combining the London Atlas and Willems' scoring method provides more precise estimates of dental age than the current practice of applying a single preferred method.

Dental age estimation using Willems method: A cross-sectional study on children in a North Indian city.

BACKGROUND: Numerous methods of age estimation have been proposed. The Demirjian method which was first applied in a French-Canadian population in 1972 is the most frequently used dental age estimation method. However, a constant over estimation using this method has been reported by numerous researchers. The Willems method is a modification of the above and was first applied in a Belgian Caucasian population in 2002. Several studies in the recent years found Willems method to be more accurate than the original Demirjians method. OBJECTIVES: The objective of this study was to evaluate the applicability of Willems method for dental age estimation in 6 -15-year-old North Indian children. METHODS: The sample for this cross sectional study consisted of 390 OPGs of (215 boys and 175 girls) randomly selected from the patient records of a post graduate training dental college in North India. Exact chronological age of the subjects (in years and months) was calculated. The OPGs were used to score the seven mandibular teeth and dental age was estimated using the tables proposed in Willems method. RESULTS: Significant correlation between the chronological age and dental age estimated using Willems method was observed in both males (r = 0.90) and females (r = 0.87). The mean difference between estimated DA and CA for males was 0.004 ± 1.08 years (P = 0.94). While for females, it was 0.031 ± 1.18 years (P = 0.72). The results showed no statistically significant difference between chronological age and dental age estimated using Willems method in the study population. CONCLUSION: Willems dental age estimation method without any modification can predict the chronological age of 6-15 year old North Indian children with good accuracy.