Mineralization Defects in the Primary Dentition Associated With X‐Linked Hypophosphatemic Rickets

Abstract

ABSTRACT X-linked hypophosphatemia rickets (XLH) is caused by inactivating mutations in the phosphate-regulating endopeptidase homolog, X-linked (PHEX) gene, leading to renal phosphate wasting and hypophosphatemia. Subjects and Methods Study participants Written informed consent was obtained from legal guardians, and assent was obtained from six pediatric patients with XLH enrolled under an institutional review board protocol approved by The Ohio State University and Nationwide Children's Hospital (Columbus, OH). For root dentin thickness, we identified the most apical extension of enamel in the axial orientation and moved apically 150 μm to outline an ROI consisting of 0.5 mm. Enamel and dentin thicknesses were measured using a cortical bone thickness algorithm for the defined ROIs that was adapted from Bouxsein and colleagues, where average thickness of the cylinder over the z-stack is calculated. Patient 1 was diagnosed by clinical presentation, strong family history, and biochemical and radiographic findings consistent with XLH; therefore, no genetic testing was performed.