Learning curve using the Sunnybrook Facial Grading System in assessing facial palsy: An observational study in 100 patients

Little is known about facial function assessments of inexperienced observers in facial palsy. In this observational study learning curve was examined of two inexperienced observers assessing facial function of 100 patients using the Sunnybrook Facial Grading System. Interobserver agreement gradually improved over time, stabilizing after approximately 70 assessments. Best agreement on the voluntary movement subscore was observed, followed by synkinesis and resting symmetry subscores. Inexperienced observers can perform facial function assessments in facial palsy, but should be adequately trained first.