Application of third molar maturity index for Indonesia minimum legal age of marriage

Abstract

Background: Child marriage is recognized as a harmful practice. Recently, Indonesia enacted a new law to raise the minimum age of marriage from a previous 16 to 19 years old for woman, creating no age difference between male and female. This improvement may come at a disadvantage regarding individuals in isolated districts that do not have any legal documentation and common practices of age falsification to reach the minimum age of marriage. Therefore, an implementation of age estimation technique for juveniles was mandatory to reduce the risk of child marriage. Methods: In this study, we used the third molar maturity index (I_3M) measurement technique to distinguish an individual below or above 19 years old. I_3M value from 222 digital OPGs aged between 15 to 23.99 years were calculated. Samples were randomly assigned as a training dataset (n = 156) and testing dataset (n = 66). Logistic regression model was created through 5-fold cross validation method, and Youden’s Index Value was used to establish I_3M cut-off value. Results: The logistic regression model shows a significance in both sex and I_3M value for predicting the probability of minimum age of marriage. I_3M cut-off value of 0.08 and 0.09 for male and female, respectively, were taken. The accuracy of this test was 80% for both sexes in the testing dataset. Conclusions: I_3M measurement technique can be utilized to assess if an individual has reached the required minimum age of marriage in Indonesia.