Second to fourth digit ratio (2D:4D) as the 'anatomical marker' and reproductive 'hormonal fingerprint' in the occurrence dental plaque accumulation.

OBJECTIVES: Digit ratio (2D:4D), as endocrine fingerprint, can indicate prenatal androgen exposure. It serves as an anatomical marker for various systemic diseases and a few studies relating it to oral health. The present study aims to evaluate the association between digit ratio and susceptibility to dental plaque formation.

METHODS: The study was conducted on young adults aged between 18 and 25 years. Digit ratio and reproductive hormones were measured; dental plaque score and gingival index (GI) were recorded. Data were analysed using the MedCalc. v.20.

RESULTS: Male and female participants were categorized into two groups based on their digit ratios being either above or below the calculated average (0.99 for females, 0.98 for males). Those with a digit ratio below the average had a significantly higher mean dental plaque score (p < 0.0001) than those with ratios at or above the average. However, there was no significant difference in the GI between the two groups. Reproductive hormone profiles varied significantly between the higher and lower digit ratio groups for both sexes.

CONCLUSIONS: Digit ratio may find potential to be used as an anatomical marker to identify the susceptibility to dental plaque build-up.