Effect of vitamin D during orthodontic tooth movement on receptor activator of nuclear factor kappa-β ligand expression and osteoclast number in pregnant wistar rat (Rattus novergicus - Narmada, I B; Husodo, K RD; Ardani, I GAW; Rahmawati, D; Nugraha, A P; Iskandar, R PD (JKIMSU, 2019)