PURPOSE: 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, Netherlands), a facial expression analysis software, was used to analyze 77 post-transplant videos of 8 FT patients from Boston, USA (range, 1-9 years), 2 FT patients from Helsinki, FIN (range, 3-4 years), and 3 FT patients from Antalya, TUR (range, 6.5-8.5 years). 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 to respective healthy controls to calculate percent restoration.
RESULTS: Out of 13 FT patients, 8 were full FT, 5 were partial FT and 2 patients were female. Compared to healthy controls, the median restoration of motor function was 40.4% (IQR 30.8%-52.9%) for patients with full FT, 32.0% (IQR 28.2%-52.8%) for patients with partial FT and 36.9% (IQR 28.8%-52.9%) for all patients with FT. When facial nerve coaptation was performed at branch level, average motor function restoration was 42.7% ± 11.4% compared to 27.9% ± 11.6% at trunk coaptation level (p=0.032). Use of interpositional nerve grafts had no influence on motor outcomes.
CONCLUSION: Software-based analysis is suitable to assess motor function after FT. International collaboration strengthens outcome data for FT.