Human permanent tooth sizes are associated with genes encoding oestrogen receptors.

OBJECTIVE

To evaluate if genetic polymorphisms in the oestrogen receptor 1 () and oestrogen receptor 2 () genes encoded for oestrogen receptors alpha (ERα) and beta (ERβ) are involved in permanent tooth size.

DESIGN

Cross-sectional study.

SETTING

Orthodontic Clinic at School of Dentistry of Ribeirão Preto, University of São Paulo.

PARTICIPANTS

A total of 108 orthodontic patients.

MATERIALS AND METHODS

Pre-treatment orthodontic records were evaluated. Dental casts were used to determine the maximum crown measurements of fully erupted permanent teeth in the mesiodistal dimensions. Second and third molars were not included in the analysis. Genomic DNA samples were used for the genotyping of four genetic polymorphisms: (rs9340799 and rs2234693) and (rs1256049 and rs4986938). The associations between tooth size and sex were evaluated using t test. The associations between tooth size and genotype were analysed with linear regression and adjusted by sex at an alpha of ⩽0.05.

RESULTS

Female patients presented smaller tooth size than male patients. A statistically significant difference was observed in almost all teeth (<0.05). The genetic polymorphisms in rs9340799, rs2234693, rs1256049 and rs4986938 were associated with some tooth sizes in both the maxilla and mandible (<0.05).

CONCLUSION

This study provides evidence that genetic polymorphisms in and could be associated with tooth size in permanent teeth.