All animal care and treatment procedures were approved by the Animal Care and Use Committee of Johns Hopkins University (Hopkins-IACUC Protocol No. MO14M326) and were carried out in accordance with institutional standards. Timed-pregnant CD-1® mice (Charles River Laboratories, Wilmington, MA, USA) were used in the study. Mice received a low dose fluoride concentration of about 6 mg/L. Sodium fluoride (NaF) was purchased from Sigma-Aldrich (St. Louis, MO, USA). Timed-pregnant CD1 mice consumed water with 6mg/L LF− and 113mg/L HF− from E9 to postnatal day (PND) 19. Maternal water and food intake were recorded daily until delivery.