Association between the prenatal hormonal signature (2D:4D ratio) and mandibular radiomorphometric parameters in...

Prenatal hormonal influences have been proposed to contribute to craniofacial development, and the second-to-fourth digit ratio (2D:4D) is widely used as a non-invasive proxy marker of prenatal androgen exposure. However, it remains unclear whether this signature is reflected in mandibular growth during childhood, particularly in the prepubertal period when pubertal hormonal effects have not yet emerged. This study aimed to evaluate the association between the 2D:4D ratio and radiomorphometric indicators of mandibular growth in prepubertal children.

This cross-sectional study included 300 prepubertal children aged 6-12 years. Right- and left-hand 2D:4D ratios were measured using a digital caliper. Mandibular radiomorphometric parameters-including gonial angle, mandibular cortical width, mandibular height, panoramic mandibular index, and antegonial notch depth-were assessed on standardized digital panoramic radiographs. Associations were examined using correlation analyses and multiple linear regression models adjusted for chronological age, sex, and body mass index.

No significant associations were identified between the 2D:4D ratio and mandibular radiomorphometric parameters. In contrast, chronological age showed significant associations with mandibular cortical width, mandibular height, panoramic mandibular index, and antegonial notch depth. Body mass index was independently associated with mandibular height and panoramic mandibular index. Although gonial angle values were higher in boys, the effect size was small and did not influence overall mandibular growth patterns.

Mandibular growth during the prepubertal period appears to be shaped primarily by postnatal somatic growth rather than prenatal hormonal signatures. Accordingly, the 2D:4D ratio should be considered a limited and context-dependent indicator rather than an independent biomarker of mandibular growth in prepubertal populations.