VDR Deficiency Caused Enamel and Dentin Hypoplasis in Mice

Vitamin D receptor (VDR) deficiency causes defects in bone mineralization and bone loss. As dentin and enamel are mineralized tissue, it is likely that this defect will cause abnormal mineralization in these tissues. Objective: To investigate and provide evidence that VDR deficiency causes hypoplastic defects in the enamel and dentin using a VDR deficient mouse model. Methods: Six wild type mice (vdr +/+) and six VDR deficient (vdr -/-) littermates were sacrificed at 70.5 days of life. The mandibles were dissected, fixed and desiccated for Micro-CT examination. The thickness, volume and width of the enamel and dentin were compared in different sites along the mandibular incisors of both groups of animals. The measurements were analyzed using NIH Image 1.63 software. Results: We observed that the thickness and the volume of the enamel were substantially reduced in the vdr -/- mice (P<0.05) when compared to the wild type mice. Similarly, it was found that the volume and the thickness of the dentin were significantly reduced in the animals with VDR deficiency when compared to wild type (P<0.05). The reduced volume and thickness of enamel and dentin could be due to defective mineralization. Conclusion: We conclude that VDR deficiency may be the cause of hypoplasia in the enamel and dentin of these mutant mice.