The ideal gluteal contouring in Thai-transwomen: cross-sectional descriptive study.

Background: Gluteal contouring is one of the major concerns of transwomen worldwide. Hip and gluteal surgery, as one type of gender-affirmation surgery (GAS), is now increasing in popularity to alleviate gender incongruence. This study investigated the ideal buttock shape in the Thai-transwomen population, which can further aid in the guidance for hip and gluteal surgery. Methods: A cross-sectional descriptive study was done on transwomen attending services at Tangerine Community Health Center, the Plastic and Reconstructive Surgery Clinic in Chulalongkorn Hospital, and Gender Health Community from 2022 to 2023. Participants were inquired about their ideal gluteal contouring using survey images of gluteal contouring of varying proportions and gluteal shapes on posterior and lateral views. Results: Among 373 participants, the most preferred waist-to-hip ratio (WHR) in the posterior view and lateral view were 0.65 and 0.70, respectively. Regarding gluteal convexity, many participants preferred round shape buttocks the most (47.45%), followed by the A-shape (43.97%), square shape (7.77%) and, V-shape (0.80%). In the gluteal projection aspect, the most attractive type was the middle buttock type which data were congruence among each subgroup population. Conclusions: The image of a narrowing waist proportionated with a widening hip on the posterior view, with the WHR of 0.65, could be considered an ideal perception of beauty in transwomen. It could help the patient in decision-making and guiding the surgical planning.