The association between osteocalcin gene polymorphism and dental fluorosis among children exposed to fluoride in People's Republic of China

Excessive fluoride intake has been shown to affect dentin and cementum mineralization throughout life. Some studies indicated that a HindIII polymorphism, of osteocalcin (OC) gene, was associated with bone metabolism-related diseases. Therefore, it is possible that the variation in OC genotypes will be associated with dental fluorosis (DF) status and/or serum caciotropic hormone level. A case-control study was conducted among children aged 8-12 years in Henan Province, PR China to investigate the association between dental fluorosis, serum calciotropic hormone level, and polymorphisms in the OC gene. HindIII polymorphism in OC gene was genotyped using the PCR-RFLP procedure. OC and calcitonin (CT) level in serum was detected using radioimmunoassay. No significant difference was observed for OC HindIII genotypes among the cases with dental fluorosis, the controls from endemic fluorosis area (EFA) and the controls from non-endemic fluorosis area (NEFA). A significant negative correlation was observed between serum calcium and OC level. No significant relationship was found between OC HindIII polymorphisms and the level of OC and CT. In conclusion, OC HindIII polymorphisms may not be a useful genetic marker for differential risk of dental fluorosis among children in PR China.