Chemical composition changes in deciduous teeth from two congenital disorders

Objectives: The purpose of this study was to assess the extent to which mineralization differs in earlier and later forming cusps of the mandibular second primary molar (DM2). The analysis was done on teeth of normal children and the findings were compared to those for children with Cerebral Palsy (CP) and Down's syndrome (DS). Methods: Two thin ground sections (100-150 micron) were prepared from each tooth, bisecting the mesial and distal cusps respectively. The chemical analysis of each section was carried out using an energy dispersive spectrophotometer (ESR). The elements evaluated by molecular weight included calcium, phosphorus, carbon and oxygen. Results: In teeth from normal children the Ca/P ratio for enamel and dentin in the distal cusps was significantly higher than that of the mesial cusps. In DS teeth, the Ca/P ratio of the mesial cusps was significantly higher than that of the mesial cusps in the normal teeth, while the Ca/P ratio in the distal cusps was similar. In CP teeth the Ca/P ratio in the mesial cusps was also higher than that of the normal teeth, but the Ca/P ratio in the distal cusps was lower than that of the normal teeth. Conclusion: Our results show that in normal children the mesial cusps, the first ones to develop, are more highly mineralized that the later forming distal cusps. In DS children, the mineralization is impaired in both the mesial and distal cusps. In CP children, the mesial cusps are even more severely affected, but the distal cusps show improved mineralization. This study shows that the early stages of calcification of the DM2 are affected in both DS and CP children, suggesting that in both conditions, there is some impairment of development even before birth.