Fig. 4

Chronological age (CA) and dental stage age (DA) of 126 LDST at each developmental stage. The numbers on the bottom refer to eleven developmental stages according to Kuremoto et al. The blue point represents the median dental stage age (DA), which refers to the normal developing age of permanent teeth at the corresponding developmental stage [24]. The red point represents the median chronological age (CA) of LDST at the specific developmental stage. The number at the top represents the median discrepancy between CA and DA for all LDST at each stage. Because no LDST at stage 1 was found, the corresponding position is denoted by “-”