Epigenetics: unravelling the molecular mechanisms that underpin dental development

Methods: We subjected 60 DNA samples from 30 MZ twin pairs to epigenetic analysis (genome-wide microarray methylation profiling).  A control group of concordant MZ pairs was compared with a group of discordant pairs for missing and extra teeth. All groups were ascertained across a broad range of tooth sizes, and an approximately equal distribution of males and females was selected.

Results: DNA samples were taken at the time of phenotyping, approximately 20 years ago. Although a degree of degradation was evident, our samples were still of high quality. Preliminary results have shown that there is a substantial degree of discordance in epigenetic profiles between many MZ twin pairs and that discordance may be greater for twins with discordant dentitions.

Conclusions: Our preliminary analysis suggests that, at a genome-wide level, there may be an influence of methylation status on tooth formation, manifesting in variation in the presence or absence of teeth.  Further analyses are required to investigate effects on tooth size and more sophisticated site-specific analyses are also required to investigate specific genes.  Epigenetics research is now being applied in several areas of dentistry and promises to have far-reaching clinical implications in the future.

Acknowledgements: We acknowledge the NHMRC, ADRF, Foundation for Children and Colgate for their support and we thank the twins and their families for their participation.