Facial Expression after Face Transplant: An International Face Transplant Cohort Comparison

Abstract

Background: Assessment of motor function restoration following face transplant (FT) is difficult, as standardized, bilateral tests are lacking. This study aims to bolster support for software-based analysis through international collaboration. Methods: FaceReader (Noldus, Wageningen, The Netherlands), a facial expression analysis software, was used to analyze posttransplant videos of eight FT patients from Boston, Massachusetts (range, 1 to 9 years after transplant), two FT patients from Helsinki, Finland (range, 3 to 4 years after transplant), and three FT patients from Antalya, Turkey (range, 6.5 to 8.5 years after transplant). Age-matched healthy controls from respective countries had no history of prior facial procedures. Videos contained patients and controls performing facial expressions evaluated by software analysis using the Facial Action Coding System. Facial movements were assigned intensity score values between 0 (absent) and 1 (fully present). Maximum values were compared with respective healthy controls to calculate percentage restoration. Results: Of 13 FT patients, eight patients were full FT, five patients were partial FT, and two patients were female patients. Compared with healthy controls, the median restoration of motor function was 36.9% (interquartile range, 28.8% to 52.9%) for all patients with FT (P = 0.151). The median restoration of smile was 37.2% (interquartile range, 31.5% to 52.7%) for all patients with FT (P = 0.065). When facial nerve coaptation was performed at the distal branch level, average motor function restoration was 42.7% ± 3.61% compared with 27.9% ± 6.71% at the proximal trunk coaptation level (P = 0.032). Use of interpositional nerve grafts had no influence on motor outcomes. Conclusions: Software-based analysis is suitable to assess motor function after FT. International collaboration strengthens outcome data for FT. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.