Osseous Transformation with Facial Feminization Surgery: Improved Anatomical Accuracy with Virtual Planning

Abstract

Background: Facial feminization surgery entails a series of surgical procedures that help the transwoman pass as their affirmed gender. Although virtual surgical planning, with intraoperative cutting guides, and custom plates have been shown to be helpful for craniomaxillofacial reconstruction, they have not yet been studied for facial feminization surgery. The authors used cadaveric analysis for morphologic typing and to demonstrate the utility of virtual surgical planning in facial feminization surgery procedures. Methods: Male cadaveric heads underwent morphologic typing analysis of the frontal brow, lateral brow, mandibular angle, and chin regions (n = 50). Subsequently, the cadavers were split into two groups: (1) virtual surgical planning intraoperative cutting guides and (2) no preoperative planning. Both groups underwent (1) anterior frontal sinus wall setback, (2) lateral supraorbital recontouring, (3) mandibular angle reduction, and (4) osseous genioplasty narrowing. Efficiency (measured as operative time), safety (determined by dural or nerve injury), and accuracy (scored with three-dimensional computed tomographic preoperative plan versus postoperative result) were compared between groups, with significance being p < 0.05. Results: For frontal brow and lateral lower face, morphologic type 3 (severe) predominated; for lateral brow and chin, type 2 (moderate) predominated. For frontal sinus wall setback, virtual surgical planning improved efficiency (19 minutes versus 44 minutes; p < 0.05), safety (100 percent versus 88 percent; p < 0.05; less intracranial entry), and accuracy (97 percent versus 79 percent; p < 0.05) compared with no preoperative planning. For mandibular angle reduction, virtual surgical planning improved safety (100 percent versus 88 percent; p < 0.05; less inferior alveolar nerve injury) and accuracy (95 percent versus 58 percent; p < 0.05). Conclusions: Preoperative planning for facial feminization surgery is helpful to determine morphologic typing. Virtual surgical planning with the use of cutting guides/custom plates improved efficiency, safety, and accuracy when performing four key craniofacial techniques for facial feminization.