UCSF Study Provides Objective Guidelines to Support and Improve Gender-Affirming Facial Surgery

April 14, 2022
Rahul Seth, MD

Facial plastic surgeons can adjust facial features to better reflect gender identity for transgender and gender diverse individuals. However, up until now, there have been few objective guidelines to justify and facilitate effective surgical decision-making for gender-affirming facial surgery (GFS). Researchers from UC San Francisco and the University of Calgary set out to quantify the effect of sex on adult facial size and shape through an analysis of three-dimensional (3D) facial surface images.

Their study was recently published in Facial Plastic Surgery & Aesthetic Medicine. Thus far, this research has achieved a high Altmetric Attention Score of 103, representing the top five percent of all research outputs scored.

"We were able to prove that there is biological differentiation of these different areas of the face between the sexes, to exemplify that surgical changes need to be made of each of these areas in order to give a change that is truly feminine or masculine," said Rahul Seth, MD, senior author and associate professor in the Facial Plastic and Aesthetic Surgery division of the Department of Otolaryngology – Head and Neck Surgery (OHNS) at UCSF in a recent interview with KJZZ, a National Public Radio (NPR) affiliate. 

The team analyzed 3D scans of more than 500 males and 1,000 females, and they found one-third of variations in the form of facial features were linked to biological sex. Male faces measured around seven percent larger, while female faces characteristically displayed larger cheeks and smaller, less prominent brows, noses, and chins. Findings will help inform patients and surgeons, and also help influence insurers and policy makers.

"It's about covering the many aspects of the face, not just the brows or the jaw. This information, along with future outcomes-based research, establishes an important, definitive, and biologically based relationship of facial features to sex. All of this empowers a patient to navigate towards a facial appearance that matches with their gender identity, and thereby reduces mis-gendering and gender dysphoria while improving self-perception," says Dr. Seth.

What's next? According to Dr. Seth, expanded research is planned to include other races and ethnicities beyond people of European-Caucasian ancestry. This process will take time, however in the interim, the current findings don't just look at isolated features, but rather relationships between them and are broadly applicable. The published analysis should be able to account for variations and patterns that are more global.

Co-authors from UCSF OHNS include P. Daniel Knott, MD, director of Facial Plastic and Aesthetic Surgery and Hailey Juszczak, MD, previous medical student at UCSF. Read more coverage from UCSF News.