Digit Ratio and Dental Caries: A Sexually Dimorphic Trait

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.

Association of Hormonal Fingerprints and Dental Caries: A Pilot Study

Context:

Dental caries remains the most widespread oral disease among all age groups. Hormonal fingerprints (second digit: fourth digit ratio or 2D:4D ratio) are biomarkers displaying sexual dimorphism and diverse human phenotypic traits. A person's genetic makeup may influence the occurrence of dental caries.

Aim:

The present study aimed to evaluate the influence of digit ratio on the incidence of dental caries.

Settings and Design:

Two hundred patients between 18 and 55 years, reporting for restorations or endodontic therapy, participated in the study.

Subjects and Methods:

Hormonal fingerprints (2D:4D ratio) were measured with the help of a digital vernier caliper. Caries incidence was recorded using the DMFT index.

Statistical Analysis used:

Data obtained were tabulated and statistically analyzed using Independent t-test and Chi-square test.

Results

Males had a less mean 2D:4D ratio than females, which was statistically significant (p-value = 0.003). Chi-square test was applied, and there was a statistically significant correlation between high digit ratio and caries experience (p-value = 0.002). Females with a high digit ratio and males with a low digit ratio were in the moderate and low caries risk groups with a p-value of 0.029 and 0.001 in the respective risk groups.

Conclusion

The present study displayed a correlation between hormonal fingerprints (2D:4D ratio) and dental caries. An indicator of caries risk will help prevent caries by implementing oral hygiene measures, which will reduce its incidence as the most occurring oral disease.