Two- and Three-Dimensional Quantification of Facial Symmetry After Fat Grafting and Free Flap Reconstruction in Hemifacial Atrophy

Hemifacial atrophy causes one side of the face to become smaller, leading to facial asymmetry. Surgeons often restore facial volume using either autologous fat grafting or free-flap reconstruction. However, it is not fully clear how much facial symmetry improves after surgery when measured objectively using two-dimensional (2D) photographs and three-dimensional (3D) surface scans. This is a single-center, retrospective observational study of patients with hemifacial atrophy treated between January 2020 and December 2023 at \[Plastic Surgery Hospital, Chinese Academy of Medical Sciences \& Peking Union Medical College\]. We will quantify facial symmetry before surgery and at the first follow-up visit occurring at or beyond 6 months after the initial surgery. Symmetry outcomes will be assessed using standardized 2D photographs for all included patients, and 3D surface scans for a subset of patients. Complications will also be assessed at the first ≥6-month follow-up visit. We will compare changes in symmetry between patients treated with fat grafting and those treated with free-flap reconstruction.