|Year : 2018 | Volume
| Issue : 1 | Page : 72-74
Demirjian method of age estimation using correction factor among Indian children: A retrospective survey
Priyadarshini Chandramohan1, Manjunath P Puranik2, SR Uma2
1 Department of Health and Family Welfare, District Hospital, Chamarajanagar, India
2 Department of Public Health Dentistry, Government Dental College and Research Institute, Bengaluru, Karnataka, India
|Date of Submission||09-May-2017|
|Date of Acceptance||08-Feb-2018|
|Date of Web Publication||23-Mar-2018|
Dr. Priyadarshini Chandramohan
District Hospital, Chamarajanagar, Karnataka
Source of Support: None, Conflict of Interest: None
Introduction: Age estimation is relevant in the field of medicine and dentistry, especially when matters of consent or identification or criminal liability arise. Dental age (DA) estimation is one of the most accurate, reliable methods of age determination. Among various radiological methods reported, Demirjian method is widely used for DA determination in children. Very few studies are reported using this method among the Indian population. Aim: The aim of this study is to assess and compare DA using Demirjian method with chronological age (CA) and determine correction factor if any among 11–16-year-old children in Bengaluru city, India. Materials and Methods: A retrospective study was performed from the archives of case records and panoramic radiographs of 200 children aged 11–16 years in a dental college in Bengaluru. DA was estimated using Demirjian method and compared with the CA that was obtained from records. Statistical Analysis Used: Student's t-test and Pearson's correlation test were used. A P < 0.05 was considered to be statistically significant. Results: There was statistically significant difference between DA and CA for boys and girls (boys: 13.80 ± 1.34 and 14.19 ± 1.54; girls: 13.80 ± 1.55 and 14.29 ± 1.46) (P < 0.01). Overall positive correlation was observed between CA and DA (r = 0.685) (P < 0.001). The correction factor was found to be 0.809. Conclusion: Considering the correlation between estimated DA and CA, it is concluded that Demirjian method can be applied in this population with a suitable correction factor.
Keywords: Age determination, chronological age, Demirjian's method, India
|How to cite this article:|
Chandramohan P, Puranik MP, Uma S R. Demirjian method of age estimation using correction factor among Indian children: A retrospective survey. J Indian Assoc Public Health Dent 2018;16:72-4
| Introduction|| |
Age systems have been studied by many anthropologists. Age is often a major organizing principle in many instances. Accurate age data is required to estimate the exact timing for the treatment procedure in endocrinology, pediatric dentistry, and orthodontics. It is also needed in forensic science where age plays an important role in the identification of deceased persons and when matters of consent, for sports, child labor, or criminal ability arise. Due to variations, developmental, biological, and chronological age (CA) may not be same. Accurate information of age or date of birth may not be available with individuals or they may choose to suppress such information. In such circumstances, age determination technique, that is, estimation of CA may be required.
Hence, many proxy indicators for biological age and body development are considered such as bone age, dental age (DA), mental age, and other factors such as menarche, voice change, height, and weight are considered. Dental development is more reliable as an indicator of biological maturity in children, as it is more relevant and is less affected by nutritional and endocrine status. Dental maturity often is expressed as an indicator of the biological maturity of growing children. It is also widely used to estimate the CA of children of unknown birth records as it is less affected by nutritional and endocrine status. Besides, tooth with its developmental stages provides us with a noninvasive modality to predict the age of the person.
Several DA estimation methods have been described based on the degree of calcification observed in the radiographic examination of the permanent dentition. The most widely used method for the comparison between different populations was first described in 1973 by Demirjian et al. His method is based on the development of seven left permanent mandibular teeth. Tooth formation is divided into eight stages and criteria for stages are given for each tooth. Each stage of the seven teeth is given a score according to a statistical model. The sum of the scores of the seven teeth represents the obtained dental maturity that can then be converted into DA by use of a conversion table. Separate standards are provided for each sex.
Most of the studies using Demirjian's method have reported overestimation ,,,,,,,,,, among various populations and accordingly have developed their own population-based specific standards.
Studies in Indian population have also reported overestimation.,, However, population-based specific standards or correction factors are virtually nonexistent. Hence, the aim of the present study was to assess DA using Demirjian method and compare with CA, among 11 to 16 years old children in Bengaluru city and determine correction factor if any.
| Materials and Methods|| |
A retrospective study was conducted for 2 months between August and September 2015 in a dental college in Bengaluru. Ethical approval was obtained from the Institutional Ethical Committee (GDCRI/ACM/PG/PhD//2015–2016) and required permission was obtained from the head of the institution and head of the Department of Orthodontics.
Training and calibration
A total of 20 orthopantomograms (OPG's) representing various stages of tooth development of children aged 11–16 years and their clinical records were obtained from the department of orthodontics. The principal investigator was trained and calibrated for using Demirjian's method. In this method, the development of each left permanent mandibular tooth, except the third molar, are rated on an 8-stage scale from A to H, and the criteria for the stages were given for each tooth separately. The scores are added to obtain dental maturity score. Then, DA is estimated by matching using dental maturity scores and standard tables developed by Demrijan et al.
OPG's of participants aged 11–16 years with a full complement of teeth in the mandibular left side were included, whereas OPG's with distortions or crowding of teeth where the root structures of the teeth were not clearly discernible or with developmental anomalies were excluded. The study was carried out using 200 OPG's and case records of participants aged 11–16 years (males = 94 [47%]; females = 106 [53%], that fulfilled the eligibility criteria.
Data were collected using a structured proforma, which consisted demographic details such as age and gender.
The study was performed in the following sequence:
- DA was estimated using Demirjian method by a principal investigator who was blinded about the CA at the time of assessment
- Then, CA was calculated by subtracting the date of the birth from the date of the panoramic radiograph
- Calculated DA was compared with CA.
The statistical software, namely, SPSS 15.0, Stata 10.1, MedCalc 9.0.1, Systat 12.0, and R environment ver. 2.11.1 (IBM, USA) were used for the analysis of the data. Descriptive and inferential statistical analyses have been carried out. Results on continuous measurements are presented on mean ± SD and results on categorical measurements are presented in proportions. Significance is assessed at 5%. Student's t-test and Pearson's correlation coefficient analysis is used for analyzing chronologic age and DA.
| Results|| |
The CA of individuals ranged from 11 to 16 years. With similar male-to-female ratio (48:52) [Table 1] overall significant mean difference between CA and DA was observed (P< 0.001). Likewise, significant mean difference was observed between CA and DA for males (P< 0.002) and females (P< 0.001) [Table 2]. Significant mean difference between mean CA and DA was observed for the age groups 12 years (females) 13 years (females) and 14 years (males) [Table 3].
|Table 2: Comparison of mean dental and chronological age among study participants|
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|Table 3: Gender wise comparison of mean dental and chronological age among study participants|
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A moderate positive correlation was obtained between CA and DA (r = 0.685) (P< 0.001)
Based on the mean difference between obtained CA and DA, a correction factor (±) 0.5 was obtained.
| Discussion|| |
Tooth development is a useful measure of maturity, as it represents a series of recognizable events that occur in the same sequence from an initial event to a constant end point. Estimating age from teeth is generally reliable, as they are naturally preserved long after the disintegration of tissues and bones. It is least affected by environmental, nutritional, and metabolic factors. Maturational events associated with tooth formation and apical closure are less variable than other developmental events.
Various studies across the world have estimated DA among 2–17-year-old participants. Studies conducted in India have considered 5–15 years of age group. Since the current study used archives available in the dental college in Bengaluru, age available for assessment ranged from 11 to 16 years. Hence, comparisons are done wherever possible.
In this study, it was seen that DA was higher than CA in both males (0.38 years) and females (0.49 years) suggesting minor overestimation. Whereas, a study from Davanagere (6–15 years) reported overestimation of 1.20 ± 1.02 among males and 0.90 ± 0.87 among females.
A Study from Bengaluru (5–13 years) reported 0.86 years of overestimation among both the genders. While Rajasthan (7–15 years) study showed very minimal difference.
Over estimation was observed among boys and girls was reported among studies conducted, in China 3–16 years ([0.062 ± 1.09] and [0.36 ± 0.95]), Saudi Arabia 8.5–17 years ([1.97 ± 1.26] and [1.24–1.34]), Turkey 5–15 years ([0.28 ± 1.10] and [0.18 ± 0.68]), Iran 3.5 to 13.5 years ([0.15] and [0.21]), Dutch 3–17 years (0.4 years, and 0.6), Spain 2–16 years (0.87 and 0.55 years), Pakistan 11–14 years (1.17 ± 0.12 and 1.14 ± 0.02), and Brazil 6–14 (0.681 and 0.616 years).
This overestimation may be due to various reasons: positive secular trend in dental development connected with general greater height and weight of contemporary children, early sexual maturation, differences in economic status, and nutrition, cultural, and ethnic differences. Hence, epidemiological surveys are required and population-specific standards periodically.
Demirjian's method is based on French–Canadian population which was formulated in 1973. Suitability of this method has been checked among various populations. Most of the studies have reported overestimation. Similarly, Indian studies have also overestimated the CA. Considering the age as assessed by Demirjian's method and difference in CA and assessed DA a correction factor of (±) 0.5. Hence, it is suggested that obtained correction factor of (±) 0.5 may be used along with the DA estimated using Demirjian's method among Indian children aged 11–16 years.
This study is not without limitations. This is a retrospective record-based survey conducted on available information, for a short term. Hence, the impact of socioeconomic status, cultural practices, nutritional status, and body mass index could not be determined. Further prospective studies with large sample size and homogenous distribution across age and gender are suggested for the development of specific population-based standards.
| Conclusion|| |
Considering the correlation between estimated DA and CA, it is concluded that Demirjian method can be applied in this population with a suitable correction factor.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]