Estimating a person’s age is crucial in the field of forensics since it helps with the identification process. Applications for age estimation include identifying missing people, and unknown victims, categorizing immigrants, and estimating whether someone is eligible for social benefits (Cunha et al. 2009; Schmeling et al. 2008). This can be accomplished by assessing skeletal, dental, morphological, and sexual development.
Dental age is estimated by evaluating tooth eruption or tooth formation, which provides a suggestion about dental maturity. Third molars take a long time to develop, and the various stages of their development may be linked to age estimation in the age range below 20 years; it is the sole approach of its sort (Ramisetty Sabitha Devi et al. 2017). Legal age can be established by observation and measurement of the third molar maturation process (Liversidge 2008; Galić et al. 2013; Cameriere et al. 2008).
OPG is a minimally intrusive method that has been recommended by ABFO and SGFAD as a standard investigative process in dental-based identification. OPGs are frequently employed to give forensic authorities important information on the dental development of individuals because of the unexpected increase in demand for the assessment of minors’ ages in many forensic and medicolegal processes (Angelakopoulos et al. 2018).
The association between the chronological age and the third molar maturity index (I3M) was found by Cameriere et al. in 2008 (Cameriere et al. 2008 Nov). He developed a threshold (I3M < 0.08) that could be used to classify individuals as major or minor based on the measurement of the apices of the third molar. Additionally, he concluded that the individual’s majority status was significantly impacted by insufficient mineralization stages of the Demirjian staging system (Cameriere et al. 2008). Variabilities are identified due to tooth mineralization or maturation timelines; genetic, biological, and geographical factors; and diet, socioeconomic level, and ethnicity (Elamin and Liversidge 2013; Black et al. 2011).
Many research has been conducted on various populations to determine the efficacy of the third molar maturity index in identifying the legal age of persons. In a sample of 339 French people, Tafrount et al. (2019) reported an overall accuracy of 90.65%, with sensitivity for males and females of 87.1% and 95.3%, respectively, and specificity for males and females of 81.3% and 96.2%. According to Kumagai et al. (2019), 276 Koreans had an accuracy rate of 89%, and the results for sensitivity (89% for males and 84% for females) and specificity (96% for males and 93% for females) indicated a good prediction of legal age. According to Angelakopoulos et al. (2018), the sensitivity was 80%, and specificity was 95% in 833 South African people. Chu et al. (2018) found an accuracy of 94.8%, a sensitivity of 90.7%, and a specificity of 100% in 840 Chinese people.
In our study, the overall accuracy of utilizing the third molar maturity index in the classification of 18 years or older was found to be 75.90% (79.17% for males and 72.62% for females). Sensitivity was 75.60% for males and 65.02% for females, while specificity was 92.73% for males and 100% for females. This was consistent with research carried out in an Indian population by Balla et al. (2017), where the sensitivity was found to be 86.7%, 96.7% specificity, and overall accuracy to be 92.15% (93.1% for males and 91.2% for females). According to research by Sharma et al. (2017), the sensitivity was found to be 74.7% for males and 66.66% for females, while the specificity was 83.6% for males and 79.6% for females. Thilak et al. (2021) discovered similar results in a study of the Goan population, where the sensitivity was 89.9% for males and 85.4% for females, while the specificity appeared to be 90.9% for males and 93.1% for females.
Research on forensic age estimates has recently tended to focus on developing population-specific formulas that may be used to lower mistakes and enhance the accuracy of the age estimation approach (Scendoni et al. 2020). Errors in estimating age can result from either underestimating or overestimating the chronological age, as well as the mean absolute error (MAE). This was further investigated in our study, where the application of the third molar maturity index in estimating a dental age was examined using a population-specific formula provided by Balla et al. (2019), making our study the first of its type in enhancing the utility of the maturity index.
In our study, the MAE was found to be 2.15 years for males, 2.39 years for females, and 2.29 years for overall sample when modified cameriere's method was used. Similar results were found in the research by Balla et al. (2019), where the MAE was 1.59 years for males, 1.53 years for females, and 1.54 years overall. In addition, the chronological age was overestimated by 0.2 years in males and 0.13 years in females in their research. In contrast to their findings, our study overestimated the age of males between 17 and 17.9 years by less than 1 year. A 1-year underestimation was seen in the age group under 19 years.
The UT-age estimate approach used data from numerous population studies. To determine the chronological age and empirical probability that a person has reached the age of 18, Blankenship et al. (2007) compared American Blacks with whites. In his analysis, the MAE for males was estimated to be 0.44 years and 0.97 years for females, and the overall MAE was 0.70 years. These results were comparable to those of research by Kasper et al. (2009) in the Hispanic population of Texas, where the MAE was 0.67 years, 0.91 years, and 0.79 years for males, females, and the total population, respectively. According to Arthanari et al. (2021), who studied the reliability of the UT-age estimate technique in the Indian population, the MAE for males was 0.52 years, for females was 0.78 years, and the MAE overall was 0.65 years. Similarly, in our study, MAE was estimated to be 0.07 years in males, 0.19 in females, and 0.14 in the total population, which is smaller than all the prior studies reported.