Fig. 2From: Predicting chronological age of 14 or 18 in adolescents: integrating dental assessments with machine learningWhen measuring mandibular third molars with multiple roots, here is an example of a tooth with two roots. In this case, A represents the sum of the distances between the open root apices on the inner side (A = A1 + A2), and L represents the length of the third molarBack to article page