[Mineralized dental tissues: a unique example of skeletal biodiversity derived from cephaic neural crest].

Molecular and structural biodiversity characterises dental mineral tissues. Groups of matrix proteins belong specifically to each tissue; amelogenins to enamel, DSPP to dentine and CAP to cementum. A wide group of proteins is also shares with other mineralized tissues such as calcium (calbindins) and phosphate (alkaline phosphatase) handling proteins. Dental tissues organisation is also based on specific cellular programs of morpho-differentiation (polarity) and on expression patterns of proteins implicated in mineralisation. The regulation of gene expression in tooth has been analysed regarding various hormones such as vitamin D in a first step and recently transcription factors (Osf-2/Cbfa1/Aml3). Other molecular families encoded by divergent homeobox genes (Msx and Dlx) are implicated in the determinism of this gene regulation and of early development. Genetic and hormonal abnormalities of dental mineralized tissues should now be interpreted thanks to the recent availability of cellular models and of odontogenic protein promoter structure.