DENTAL ABNORMALITIES AND EARLY DIAGNOSIS OF HYPERPHOSPHATASEMIA

Dental hard tissue abnormalities have never been described as part of the symptoms associated with hyperphosphatasemia. Fourteen teeth obtai ned from a young man, who had a mild form of hyperphosphatasemia, were analyzed using scanning electron microscopy (SEM), secondary ion mass spectroscopy (SIMS), X-ray diffraction (XRD), and infrared (IR) spect roscopy. SEM revealed a thin enamel, presenting a prismatic structure with many pits, and atypical cementum and dentin showing numerous reso rption areas. The X-ray diffractograms revealed poorly crystalline hyd roxyapatite associated with alpha-tricalcium phosphate and magnesium h ydroxide phases. SIMS data showed high Ca concentrations: 40.5 weight % {wt%; standard deviation (SD) = 0.13) and 42.5 wt% (SD = 1.03) in en amel and dentin respectively, and high Ca/P weight ratios: 2.28 in the enamel, 2.65 in the dentin. The lack of crystallinity may be linked t o the high content of proteins and magnesium adsorbed onto apatite. Th is study demonstrates the need for thorough radiographical and biologi cal investigations for skeletal abnormalities, even in the absence of systemic symptoms, when generalized dental abnormalities of both ename l and dentin are observed.