トランス女性に対する顔面女性化手術

Facial Feminization Surgery for Transgender Women

はじめに

　トランス女性が女性としての社会生活を営むうえで，客観的性別評価（いわゆる「パス度」）の改善は非常に重要な要素である。人は一見にして無意識のうちに性別を判断している 1）。適切な顔面女性化手術（facial feminization surgery：以下，FFS）を行うことで「パス度」の向上を図る。

　What provides the differences between a masculine face and a feminine face? These differences should be understood when facial feminization surgery (FFS) is planned as facial contouring surgery. Male and female facial morphologies are quite different in terms of size and shape. Compared to female faces, male faces generally have a flatter forehead, an enlarged projection of frontal bossing, straight eyebrows at a slightly lower position, an M-shaped or square hairline, a larger and longer nose, thinner lips, a wider chin with more projection, a sharp mandibular angle, a more rough and angulated facial contour, and a larger laryngeal prominence. Compared to male faces, those of females have a slightly curved forehead, a minimal frontal bossing, curved eyebrows at a slightly higher position, an O-shaped hairline, a smaller nose, thicker lips, a narrow chin with less projection, a less angulated mandibular angle, and smaller, curved and smooth facial contours. Various FFS procedures are thus performed for transgender women in order to feminize the face, including contouring surgery of several facial bones and adjustments of soft tissue: forehead contouring (the burring and/or a setback osteotomy of frontal bossing), an eyebrow lift, scalp advancement, hair transplantation, rhinoplasty, malarplasty, lip lift and augmentation, genioplasty, reduction mandibuloplasty, orthognathic surgery, and a thyroid chondroplasty.

　The essences of FFSs are the reduction of the prominence, creating a curving contour and making the facial size smaller. Commonly, forehead contouring, a reduction mandibuloplasty, rhinoplasty, and hairline plasty are the most important FFS techniques, and malarplasty is also important. FFSs are effective and highly satisfactory procedures.