Raman Microspectroscopy and Ultrastructural Findings in Deciduous Tooth Affected by X-Linked Hypophosphatemic Rickets

Abstract

X-linked hypophosphatemic rickets (XLHR) is a rare condition characterized by severe bone and dental abnormalities. However, some dental aspects should be clarified. This study aimed to characterize a tooth affected by XLHR. Teeth (1 affected and 1 non-affected) obtained from a family with XLHR were evaluated by Raman microspectroscopy (RMS), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), and microhardness. RMS of the inorganic/organic matrix, carbonate/phosphate, and collagen cross-link ratios showed significant alterations in the affected dentin (interglobular dentin, calcospherites, and mantle dentin). Interglobular dentin showed the absence of hydroxyapatite peak, structural abnormalities on SEM, Ca-P index reduced on EDS, and lower microhardness. In brief, dentin affected by XLHR showed a hypomineralized pattern and low microhardness value. Additionally, RMS showed the absence of hydroxyapatite in interglobular dentin, which is not previously reported.