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. Copyright:

INTRODUCTION

Estimation of age through dental findings is most reliable due to various dynamics that is observed from the beginning of teeth formation to the final shedding.[12] According to Ancient Rome, the completely erupted second molar was considered to be the indicator of adolescents who were judged to be fit for service.[345] Correction of the reference standard developed using affluent segment of developed nations is significant for forensics is necessary if the subject for whom a dental age (DA) estimate is required from a lower socioeconomic status in a developing country.[678]

MATERIALS AND METHODS

The study was conducted using the radiographic records of candidates of the city of Bengaluru, who reported to the Department of Forensic Odontology, Government Dental College and Research Institute, Bengaluru, for age verification, as a prerequisite to participate in state and national level sports tournaments, during the years 2017–2019. A total of 205 subjects (109 boys and 96 girls) of ages ranging from 10 to 14 years were included. Subjects selected were children and adolescents who had complete mandibular dentition and free from any kind of disorder affecting the growth. Orthopantomograph (OPG) was collected from the subjects to assess and analyzed dental maturity using Willems method. The chronological age (CA) of the subject was calculated by subtracting the date of the radiograph from date of birth. Data were analyzed using Pearson correlation and Student's t-test, and any P ≤ 0.05 was considered to be statistically significant. Therefore, the aim of the present study is to check the reliability of the Willems method in the population of Bangalore.

RESULTS

A total of 205 subjects were selected for the study, among which 109 (53.2%) were boys and 96 (46.8%) were girls [Table 1]. The difference between DA and CA of both gender and age groups was calculated using independent t-test. The results showed that the mean CA and DA were 12.23 ± 1.75 and 12.20 ± 1.99, respectively. The mean age difference between DA and CA was 0.9 years for males and 0.08 years for females and these differences were statistically significant (P < 0.022) [Table 2]. Pearson's correlation test showed a significant correlation between the CA and DA (r = 0.823 P < 0.001) [Table 3]. The scattered plots generated using the software with DA (in years) on X-axis and CA (in years) on Y-axis. It was seen that there was a fair visible correlation between the CA and DA in boys, girls, and overall [Figure 1], convincing us to undertake more rigorous correlation analysis for statistical satisfaction. In the present study, significant relation was found between estimated DA and CA, and thus, the Willems method seems to be reliable in estimating age in Bangalore populations.

Table 1

Distribution of the study subjects according to gender

Age (years)	Boys	Girls	Total (n)
10	28	21	49
11	13	10	23
12	10	19	29
13	25	20	45
14	33	26	59
Total	109	96	205

Table 2

Mean, standard deviation, and difference between chronological age and dental age according to Willems method using Student’s t-test

Age group (years)	Sex	n	Mean±SD			95 % CI of mean difference		t	P
			CA	DA	Difference between CA and DA	Lower	Upper
10	Boy	28	10.03±0.58	9.96±0.84	0.07±0.19	−0.32	0.45	0.350	0.728
	Girl	21	9.79±0.56	10.0±1.08	−0.25±0.27	−0.79	0.29	−0.937	0.354
11	Boy	13	10.85±0.50	10.6±0.88	0.19±0.28	−0.39	0.77	0.688	0.498
	Girl	10	10.85±0.73	10.9±1.52	−0.10±0.53	−1.22	1.01	−0.197	0.846
12	Boy	10	11.85±0.67	12.2±1.78	−0.39±0.60	−1.65	0.87	−0.645	0.527
	Girl	19	11.89±0.74	11.3±0.83	0.61±0.25	0.095	1.13	2.399	0.022
13	Boy	25	13.22±0.41	13.5±1.01	−0.30±0.22	−0.74	0.14	−1.377	0.175
	Girl	20	13.21±0.48	12.9±0.81	0.32±0.21	−0.10	0.75	1.542	0.131
14	Boy	33	13.93±0.57	14.4±1.41	−0.43±0.27	−0.95	0.10	−1.614	0.111
	Girl	26	14.30±0.72	13.8±0.92	0.54±0.23	0.08	1.00	2.362	0.022

P<0.05 is statistically significant. SD: Standard deviation, CI: Confidential interval, CA: Chronological age, DA: Dental age

Table 3

Correlation between the chronological age and dental age using Pearson’s correlation test

Subjects	Variables	n	Mean±SD	r	P
Girls	CA	96	12.25±1.82	0.807**	0.001
	DA	96	11.98±1.74
Boys	CA	109	12.21±1.70	0.861**	0.001
	DA	109	12.40±2.17
Overall	CA	205	12.23±1.75	0.823**	0.001
	DA	205	12.20±1.99

**Correlation is significant at the 0.01 level (two tailed). SD: Standard deviation, CA: Chronological age, DA: Dental age

Figure 1

Distribution of subjects based on their dental and chronological age using scattered plot

DISCUSSION

The National Sports Development Code of India 2011 suggests in Annexure XVI that on conclusive proof available that an athlete has committed age fraud a National Sports Federation must ban that athlete from taking part in any sport for 2 years. Large variation was observed in many studies done to find the association between tooth formation and the emergence of the eruption of teeth. Tooth formation was considered to better indicator than gingival emergence of eruption, both of which were assessed radiographically.[9101112] In an age where CA is wrongly quoted for benefits with fabricated proofs, taking medical aid to estimate age is of paramount importance. Tooth mineralization stages are less affected by variation in endocrine and nutritional status and developing teeth provide a more certain indication of CA.[1314] Dental radiographs are noninvasive technique for estimating the DA. Estimation of age based on measurements of the amount of tooth mineralization present seems to be relatively reliable for they are not affected more by external factors. The OPG radiograph gives a complete developmental status of the mineralization of teeth, thus making evaluation suitable for children. There was a strong correlation between age and the amount of secondary dentin for the coronal and for the measurements in the root area using the scoring system using OPG.[15]

Demirjian et al. proposed an age estimation method using seven left mandibular permanent teeth. Later, it was modified by other coworkers where the third molar was included. A method was proposed that made use of 10 developmental stages (numbered 0–9) for the eight left mandibular permanent teeth. Based on the developmental stage of each tooth, a specific maturity score is allocated. All maturity scores are added and a total maturity score is obtained. The total maturity score is then substituted in a formula to estimate age. Willems method which is modified Demirjian's method was used to estimate DA of Belgian children for the reason the Demirjian's method overestimated the DA and this modified method gave more accurate DA estimation. This modification by Willems et al. was used to check the reliability in the Bangalore population.

CONCLUSION

There are many different DA estimation techniques for children and adolescents, forensic dentists have to judge each age estimation carefully to improve the accuracy of age estimation. Forensically age estimation plays an important role in biological identification using many methods and variables. Age estimation utilizing radiographic tooth development has seen to be an accurate method because it is less affected by nutritional and environmental factors and is mainly genetically influenced. In the present study, significant relationship was found between CA and estimated DA. Thus, the Willems method seems to be more applicable in estimating age in early adolescents of Bangalore populations.

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Conflicts of interest

There are no conflicts of interest.