Endocrine Abstracts

Background: Facial feminization or masculinization is particularly important in transpersons, both for self-image and social interaction. Females tend to have a smaller, rounder face, with more prominent cheeks and males tend to have a larger, more square face with frontal bossing. It is unknown whether cross-sex hormones can change these features. However, transgenders themselves often report facial changes due to hormone treatment. Therefore we aim to objectify if hormone treatment in transpersons can cause facial feminization and masculinization.

Design: In a single center cohort study, we studied persons diagnosed with gender dysphoria, transwomen and transmen, who were treated with a regimen of hormones according to protocol (estrogen and cyproterone acetate in transwomen and testosterone in transmen). 3D facial images were made with an Artec Spider scanner at baseline and after 3 months of treatment. The primary outcome was relative local shift of skin in millimeters after 3 months of treatment, measured in 22 soft tissue landmarks.

Results: We included 14 transwomen and 6 transmen, mean age 28.3(IQR 21.5–30.0 years). Face surface mappings (colormaps) in transwomen demonstrated a small shift of skin in the jaw and cheek region. The gonion landmark shifted towards the origin in the x-axis (mean=1.19 mm; 95%CI, −0.46 to 2.43) and the cheek landmark shifted away from the origin in the z-axis (mean=0.50 mm; 95%CI, 0.09 to 0.91). In transmen, the colormap showed a small increase in the cheek region, corresponding with a measured shift towards the origin in the z-axis (mean=−0.54 mm; 95%CI, −0.77 to −0.31).

Conclusions: In both transwomen and transmen the face shows changes in the first 3 months of treatment. In transwomen the shifts implicate a rounding of the jaw and an increase in cheek tissue. In transmen the shift implicates a decrease in cheek tissue. These changes suggest that hormonal treatment induces facial feminization in transwomen and masculinization in transmen. Furthermore, this research shows that 3D imaging is a promising tool for the evaluation of facial changes.