Regarding the role of apoptosis in the occurrence of root resorption, Minato et al. [25] found a significant increase in the number of caspase 3- and caspase 8-positive cells, as well as receptor activator of nuclear factor-kappa B ligand (RANKL)-positive cells, in the HF (50 g) group compared with the OF (10 g) group. Here, CASP3 is linked to hydrops fetalis.