Age Estimation in Indians Using Demirjian’s 8-teeth Method

Abstract

Demirjian's grading of tooth calcification is widely used to assess age of individuals with developing dentitions. However, its application on numerous populations has resulted in wide variations in age estimates and consequent suggestions for the method's adaptation to the local sample. Conventionally, Demirjian's method utilized seven mandibular teeth on the left side. A recent modification incorporated the third molar with a view to apply the method on a wider age-group. Moreover, the revised method developed regression formulas for assessing age. This paper tested the 8-teeth method using 547 Indians (348 females, 199 males) aged 7-25 years. Demirjian's formulas resulted in inferior age prediction in Indians (9.2% misclassification at 99% confidence interval vs. 0% misclassification in the original study); therefore, India-specific regression formulas were developed, which gave better age estimates (mean absolute error, MAE=0.87 years) than the original formulas (MAE=1.29 years). This suggests that Demirjian's 8-teeth method also needs adaptation prior to use in diverse populations.

Validation of third molar maturity index (I 3M ) for discrimination of juvenile/adult status in South Indian population

“…Recently, a study was conducted on South Indian children, where in which the author has tested the accuracy of three age estimation methods 65 . Despite its slight underestimation of real age, Cameriere's method 69 was proved to be the best method over Willems 70 and Acharya's method 62 . Further affirmative to the results, this study is designed to evaluate the applicability of I3M for discrimination of juvenile/adult status on South Indian subjects.…”

“…Acharya 62 was the first in Indian context to use DS approach to discriminate juvenile/adult status and reported that one in four cases resulted in "incorrect classification"…”

Evaluation of dental age and associated developmental anomalies in subjects with impacted mandibular canines

“…Exclusion criteria were chronologic age .16 years (owing to decreased accuracy of dental age estimation using Acharya's method 18 ); bilateral agenesis of the mandibular teeth (other than PMCs), teeth that were missing because of previous extractions or traumas; presence of gross caries, previous endodontic treatment of primary mandibular canines that possibly influenced eruption of PMCs, orofacial clefts, or any syndromic manifestations and history of prior orthodontic treatment.…”

“…We excluded subjects with inadequate record quality or bilaterally missing mandibular teeth. These factors could have made it impossible to assess dental age by the method 18 considered in this study.…”

Reliability of India-specific regression formula for age estimation of population in and around Bahadurgarh, Haryana (India)

“…5 This method has undergone a number of modifications, since then due to its lack of reliability in several subsequent studies. 6 In order to overrule the differences in age detection, Acharya 6 carried out a regression analysis and derived a formula incorporating third molars as well into the age estimation process in an Indian population. The aim of this study is to evaluate the reliability of the India-specific regression formula for age estimation of population in and around Bahadurgarh, Haryana (India).…”