Method error analysis
To assess the reliability of the 4D tracking of facial expressions, the same investigator repeated the application of the dummy mesh to the individual patients’ morphology in ten cases. Additionally, a second examiner performed the same task one time. Agreement was excellent for the magnitude of facial expression (ICC = 0.982; 95% CI [0.933, 0.995]) and good to excellent for the shape change in the region of interest lower face (ICC = 0.947; 95% CI [0.814, 0.986]).