Journal of South Asian Association of Pediatric Dentistry
Volume 6 | Issue 2 | Year 2023

Assessing the Accuracy of Two Dental Age Estimation Techniques—London Atlas and Demirjian’s Methods in Bengaluru Children and Young Adults: A Cross-sectional Study

Umapathy Thimmegowda1https://orcid.org/0000-0003-2426-5057, Sanchitha Venkatahanumaiah2, Jaya A Ramachandra3https://orcid.org/0000-0003-2588-7309, Amrutha Ujjamma Bennehalli4

1-4Department of Pediatric & Preventive Dentistry, RajaRajeswari Dental College & Hospital, Bengaluru, Karnataka, India

Corresponding Author: Umapathy Thimmegowda, Department of Pediatric & Preventive Dentistry, RajaRajeswari Dental College & Hospital, Bengaluru, Karnataka, India, Phone: +91 9986478744, e-mail: umapathygowda@gmail.com

Received on: 22 May 2023; Accepted on: 20 June 2023; Published on: 23 August 2023


Background: Age estimation is also done on living people in medicolegal cases, including child labor, rape, child marriages, and illegal immigration without sufficient approved documentation.

Aim: The aim of the present study was to compare the relative effectiveness of two alternative approaches—London Atlas and Demirjian’s methods—in estimating a person’s chronological age in a sample population of Bengaluru residents.

Materials and methods: From the database archives of the Dental College and Hospital, Bengaluru, and five private diagnostic facilities in Bengaluru, 464 inhabitants of Bengaluru, aged 3–18, had radiographs selected for the study. There was a record of the sex, birth date, and image data. Using deidentified orthopantomograms (OPGs), two certified examiners evaluated the dental age estimation. Both examiners concurrently analyzed and graded the stages of tooth development and eruption.

Results: There is a substantial positive and statistically significant correlation (p < 0.05) between chronological age and both biological age measures.

Conclusion: The association between Demirjian’s age and chronological age is marginally stronger than the relationship between the ages of the London Atlas and Demirjian.

How to cite this article: Thimmegowda U, Venkatahanumaiah S, Ramachandra JA, et al. Assessing the Accuracy of Two Dental Age Estimation Techniques—London Atlas and Demirjian’s Methods in Bengaluru Children and Young Adults: A Cross-sectional Study. J South Asian Assoc Pediatr Dent 2023;6(1):71-76.

Source of support: Nil

Conflict of interest: None

Keywords: Age estimation, Chronological age, Dental age, Demirjian’s approach, Forensic dentistry, London atlas method.


Age estimation in young children, preteens, and adolescents is significant in forensics as well as in the planning of orthodontic therapy and clinical dentistry. Age assessment is also done on living people in medicolegal cases, including child labor, rape (both victims and accused), child marriages, and illegal immigration without appropriate approved documentation.1 Chronological age is calculated in years for older children, whereas for younger children, it is the number of days, weeks, and months that have transpired since their birth.2,3 The capacity to determine chronological age has grown to be an essential aspect of daily life and, more importantly, a way for impoverished children to receive aid and education. Because society and the law may incorrectly regard the person as an adult, access to resources may be restricted if documentation of age is not provided to those in positions of authority1; having access to reliable and precise age estimation technologies is undoubtedly essential in cases where there is no other supporting data.4

There are various methods for calculating chronological age, all of which depend on how a person develops throughout childhood as they mature.5 Dental factors offer more reliable age estimation findings as compared to skeletal development estimation methods. Accurate age estimation in the preadult stage is required in judicial processes to determine the culpable age. Therefore, there is an urgent need for trustworthy methods that can confirm the assumed chronological age.3

Assessing the stages of tooth follicle growth and using the chronological developmental timeline have been the main methods for establishing dental age throughout the mixed dentition phase. These variables, which have been studied clinically and radiographically in numerous research, have been compared to known chronological ages to produce correlations that may be statistically represented to infer one or the other. Based on dental maturation, age estimation techniques for kids can be divided into two categories—scoring systems and atlas approaches.6

In 1973, the Demirjian technique of age evaluation developed a scoring system based on the stages of maturity of seven permanent teeth. Despite the fact that much research has proven that this method overestimates chronological age by >1 year, it is still used in many studies for evaluation and comparison with other dental age estimating methods. The accuracy of Demirjian’s approach in an Indian population has been evaluated in a few studies, with mixed results. In 2011, a study7 published a method of age estimation in Indians utilizing Demirjian’s eight-teeth method, which is suggested for estimating chronological age in heterogeneous groups.3

The London Atlas of Human Tooth Development and Eruption, introduced by AlQahtani et al.,1,8 is a comprehensive, evidence-based atlas that overcomes some of the shortcomings of prior atlases and is available worldwide. This is the most recent of the approaches used in our study, and it is a simplified atlas-based comparative evaluation of developmental phases.9

The described approaches show a bias when used on small samples of people of different ages using a single methodology. Throughout the early years, methods based on radiological examinations and assessments of dental and skeletal development are recommended, albeit accuracy declines with age.2 In order to lessen the bias among various age assessment techniques, our study investigates the accuracy of dental age estimations using two systems, the London Atlas and Demirjian’s Technique. In order to determine the chronologic age of an individual in a sample population of Bengaluru, this study compares the relative accuracy of two different procedures, London Atlas and Demirjian’s methods.


From June 2022 to January 2023, the study sample included selected radiographic images from 464 Bengaluru residents (242 males; 222 females) aged 3–18 years were taken from the database archives of Dental College and Hospital, Bengaluru, and five private diagnostic centers in Bengaluru (Fig. 1). A record of sex, date of birth, and image data were created.

Fig. 1: Orthopantomogram (OPG) of the child

Inclusion Criteria

Clear orthopantomograms (OPGs) without any position errors or artifacts of participants with all teeth in the maxillary right, mandibular right, and left quadrants, with no impacted, embedded, or transpositioned teeth, were included in the study.

Exclusion Criteria

Radiographs of subjects with any pathology or who have had extractions or restorations of maxillary right, mandibular right, or left quadrant teeth; orthodontic treatment; congenital/developmental anomalies of the jaws and teeth; history of craniofacial trauma, jaw lesion/disorder; systemic illness was excluded.

All the OPG images were traced using Adobe software for evaluation (Fig. 2).

Fig. 2: A traced image of an OPG

The discrepancy between the date of birth and the date the image was taken to compute the individual’s chronological age. Both methods used the same collection of radiographs. All of the traced images were rendered anonymous and assigned a sequential number to which the information gathered was linked while each image was examined, and the ages of the subjects were calculated using both methods.

Two qualified examiners assessed the dental age estimation using deidentified OPGs, and the stages of tooth development and eruption were assessed and graded by both examiners simultaneously, and they were blinded. After converting the ages to months to simplify the statistical analysis, the disparities between chronological age and estimated age were analyzed statistically. The two sexes were addressed individually due to well-documented variations in the rate of development between females and males.

Demirjian’s Method

The development phases of each of the seven left permanent mandibular teeth (from central incisors to second molar) (Fig. 3) were assessed on an eight-stage scale from A to H based on tooth mineralization, and the criteria for each stage were given separately for each tooth. Each of the seven phases of the teeth was assessed, and the total of the scores was used to calculate the individual’s dental maturity score, which was calculated on a scale of 0–100. Every subject’s maturity score was then converted to “dental age” using conventional tables tailored to each gender (Fig. 4).3

Fig. 3: Tooth development chart

Fig. 4: Tooth maturity score

The London Atlas Method

To examine the relative crown/root length of all eight right teeth in the upper and lower curves, a pair of London Atlas images for tooth development and eruption was used (Fig. 5).10

Fig. 5: Age estimation chart by London Atlas

Statistical Analysis

Microsoft Excel was used to accomplish all data analysis. The IBM Statistical Package for Social Sciences software was used to do the full statistical analysis (version 19). Pearson’s Correlation was used to calculate the significant differences between the chronological age and the predicted dental age (p-value). A p < 0.05 was chosen as the statistical significance level.


A total of 464 individuals (242 men and 222 females) between the ages of 3 and 18 were chosen and analyzed by gender and age group, which encompassed a 12-month range of ages. Pearson’s correlation was utilized to determine the significance of the discrepancy between chronological age and estimated dental age. Between chronological age and both measures of biological age, there is a strong positive and statistically significant (p < 0.05) association (Pearson’s correlation) (Figs 6 and 7).

Fig. 6: Shows a significant correlation between the chronological age and estimated (biological) age using Demirjian’s with a positive correlation of 0.98

Fig. 7: Shows a significant correlation between the chronological age and estimated (biological) age using the London Atlas method with a positive correlation of 0.96

Pearson’s correlation between chronological age and Demirjian’s age (Table 1) is somewhat larger (0.98 vs 0.96) than Pearson’s correlation between chronological age and the London Atlas method (Table 2), and the correlation is statistically significant with a p-value of <0.05.

Table 1: Pearson’s correlation between chronological age and Demirjian’s age
Age category Pearson’s correlation p-value
3–4 0.456 0.0379
4–5 0.711 0.0004
5–6 0.963 0.0000
6–7 0.643 0.0009
7–8 0.604 0.0023
8–9 0.170 0.3680
9–10 0.357 0.0257
10–11 −0.00259 0.9880
11–12 −0.209 0.2760
12–13 0.238 0.1560
13–14 −0.31 0.0582
14–15 0.208 0.1910
15–16 0.614 0.0000
16–17 −0.0175 0.9200
17–18 0.336 0.0521
Table 2: Pearson’s correlation between chronological age and the London Atlas method
Age category Pearson’s correlation p-value
3–4 0.456 0.0381
4–5 0.711 0.000212
5–6 0.963 0.0000000318
6–7 0.643 0.245
7–8 0.604 0.258
8–9 0.17 0.155
9–10 0.357 0.0000000893
10–11 −0.00259 0.0148
11–12 −0.209 0.0786
12–13 0.238 0.0117
13–14 −0.31 0.119
14–15 0.208 0.0315
15–16 0.614 0.000319
16–17 −0.0175 0.000939
17–18 0.336 0.000308


In forensics, methods that take into account skeletal, dental, or sexual development are commonly considered and recognized as being more precise ways to determine age. Many techniques for age estimation utilizing tooth developmental stages have been a key asset in forensics and law enforcement.5,6 These methods have been created and used for roughly 50 years, and they are straightforward and reliable for figuring out how old a population is. Due to variations in how genetic diversity manifests itself in the phenotypes of different ethnic groups, environmental conditions and social changes cause subtle yet perplexing changes in the pace of growth and chronological age of diverse ethnic groups. To make sure they can be utilized as a diagnostic tool and are sensitive enough to be helpful, this necessitates regular age updates and reestimation using established procedures.7-10

The people of Bengaluru are an excellent illustration of a rapidly developing civilization that has experienced significant changes in socioeconomic dynamics throughout time as a result of increased global migration, environmental issues, intermarriage, and other causes, among others. The factors that propel growth and development may have been impacted by these changes. The actual proof of these growth effects will be shown by estimating the population’s age today and comparing it to past surveys.11-13 In our study, we used two noninvasive (radiographic) age assessment techniques—the Demirjian approach and the London Atlas method. Both techniques have received widespread approval, are straightforward in their methodology and nature, and provide schematic illustrations of tooth development. These techniques can be used to determine a person’s chronologic and growth-related dental age during their formative years.14 This study’s objective was to establish the chronological age of the Bengaluru population using the amount of tooth growth as a standard. This will enable the verification and recalibration of the corrections required to make the age determination acceptable in contemporary society.

Using the phases visible in a person’s teeth, Demirjian’s method was developed to estimate their age. This chart has limitations because it was made for a French–Canadian community, which must be fixed before it can be applied to other ethnic groups.15 Demirjian’s method did not reveal any statistically significant deviation from chronological age in either males or females in our investigation. We think that Demirjian’s method’s higher accuracy can be attributed to the age range covered by the research. The development of teeth may have been impacted by dietary and lifestyle changes. In comparison with our study, a study stated that this might be caused by varying degrees of sexual dimorphism or differences in environmental stresses dependent on sex.2

The London Atlas was the most current methodology compared in this study, having been produced in 2010. Minor differences were seen between the estimated and chronological ages of both boys and girls, and in both cases, the estimated age was higher than the actual age. This shows that the dataset used to create the London atlas has grown and developed differently than the contemporary Bengaluru population that was studied; similarly, a study showed no statistical difference and advocated that more research is necessary to identify which factor has a stronger impact on causing inequalities in dental age.16

In a strict sense, a better method should demonstrate the precision of the difference between dental and chronological ages as well as the constancy of the anticipated ages over repeated measurements. With an accuracy of “plus or minus 1 year,” dental maturation can be used to forecast dental age, which is particularly helpful when doing so for preadolescents and adolescents.17 Changes in the surroundings and diet of the urban youth evaluated may have an impact on the results. Children’s growth and development speed up when they consume a diet high in refined carbs and sugary drinks. Growth patterns can differ between boys and females depending on changes in food. Since the Demirjian method’s accuracy has increased in comparison to earlier studies carried out nearly 10 years ago, this was also seen in our research.

Our sample only represents a small fraction of Bengaluru, which means that the current study is limited in that it could not be typical of the general population. As a result, the developed prediction equation needs to be altered before being applied to the total Bengaluru population. Small cohort sizes, the clinical nature of the sample, the children’s age range of 3–18 years, which included very young children showing the early stages of permanent tooth development, and the cross-sectional nature of the data, which is always a limitation when examining growth patterns, were other limitations. Based on a larger reference population, greater research on Bengaluru children is therefore advised.


Dental development is a more reliable indicator of a child’s biological maturity from infancy to late adolescence. Chronological age and dental age are observed to be synchronized in a healthy child. In forensic situations, a number of biometric methods for figuring out a person’s age have been shown to be reliable. In this study, there is a somewhat greater correlation between chronological age and Demirjian’s age than between chronological age and the London Atlas method. Periodic analyses of population growth changes and updates to previously set adjustment values for age estimation approaches are essential in today’s changing society.

Why is this paper important to pediatric dentists?


We thank Dr Nagarathna C, Head of the Department, Department of Pediatric and Preventive Dentistry, for her constant support throughout the study. Also, we thank Dr Balaji, Head of the Department, Department of Oral Medicine and Radiology, for his support and timely guidance throughout the study.


Umapathy Thimmegowda https://orcid.org/0000-0003-2426-5057

Jaya A Ramachandra https://orcid.org/0000-0003-2588-7309


1. AlQahtani S, Kawthar A, AlAraik A, et al. Third molar cut-off value in assessing the legal age of 18 in Saudi population. Forensic Sci Int 2017;272:64–67. DOI: 10.1016/j.forsciint.2017.01.004

2. Pavlović S, Palmela Pereira C, Vargas de Sousa Santos RF. Age estimation in Portuguese population: The application of the London atlas of tooth development and eruption. Forensic Sci Int 2017;272:97–103. DOI: 10.1016/j.forsciint.2017.01.011

3. Alshihri AM, Kruger E, Tennant M. Dental age assessment of 4-16-year-old Western Saudi children and adolescents using Demirjian’s method for forensic dentistry. Egypt J Forensic Sci 2016;6(2):152–156. DOI: https://doi.org/10.1016/j.ejfs.2015.03.003

4. Patel PS, Chaudhary AR, Dudhia BB, et al. Accuracy of two dental and one skeletal age estimation methods in 6-16 year-old Gujarati children. J Forensic Dent Sci 2015;7(1):18–27. DOI: 10.4103/0975-1475.150298

5. MK LJ, Shenoy P. Accuracy of two dental age estimation methods in 6-18-year-old children-a radiographic pilot study. IOSR-JDMS 2017;16(9):90–93. DOI: 10.9790/0853-1609069093

6. Al-Dharrab AA, Al-Sulaimani FF, Bamashmous MS, et al. Radiographic evaluation of dental age maturity in 3-17- years-old Saudi children as an indicator of chronological age. J Orthod Sci 2017;6(2):47–53. DOI: 10.4103/jos.JOS_1_17

7. Alshihri AM, Kruger E, Tennant M. Dental age assessment of Western Saudi children and adolescents. Saudi Dent J 2015;27(3):131–136. DOI: 10.1016/j.sdentj.2015.01.002

8. Alshihri AM, Kruger E, Tennant M. Integrating standard methods of age estimation in western Saudi children and adolescent. Eur J Forensic Sci 2016;3(4):1. DOI: 10.5455/ejfs.201936

9. Demirjian A, Goldstein H, Tanner JM. A new system of dental age assessment. Hum Biol 1973;45(2):211–227.

10. Willems G, Van Olmen A, Spiessens B, et al. Dental age estimation in Belgian children: Demirjian’s technique revisited. J Forensic Sci 2001;46(4):893–895.

11. AlQahtani SJ, Hector MP, Liversidge HM. Accuracy of dental age estimation charts: Schour and Massler, Ubelaker and the London Atlas. Am J Phys Anthropol 2014;154(1):70–78. DOI: 10.1002/ajpa.22473

12. Alassiry A, Alshomrani K, Al Hasi S, et al. Dental age assessment of 3-15-year-old Saudi children and adolescents using Demirjian’s method-a radiographic study. Clin Exp Dent Res 2019;5(4):336–342. DOI: 10.1002/cre2.186

13. Baghdadi ZD. Dental maturity in Saudi children using the Demirjian method: a comparative study and new prediction models. ISRN Dent 2013;2013:390314. DOI: 10.1155/2013/390314

14. Dyras M, Lyszczarz J, Wójtowicz B, et al. Dental age in the relation with nutrition model of school children from swimming classes of championship school. Wiad Lek 2002;55 Suppl 1(Pt 2):662–667.

15. McCloe D, Marion I, da Fonseca MA, et al. Age estimation of Hispanic children using the London Atlas. Forensic Sci Int 2018;288:332.e1–332.e6. DOI: 10.1016/j.forsciint.2018.04.013

16. Karimi A, Qudeimat MA, Lucas VS, et al. Dental age estimation: development and validation of a reference data set for Kuwaiti children, adolescents, and young adults. Arch Oral Biol 2021;127:105130. DOI: 10.1016/j.archoralbio.2021.105130

17. Harris EF, Buck AL. Tooth mineralization: a technical note on the Moorrees-Fanning-Hunt standards. Dent Anthropol J 2002;16(1):15–19. DOI: 10.26575/daj.v16i1.165

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