Normal Facial Function in the Sunnybrook Facial Grading System: Is the 100% Score too Restrictive?

Abstract

The primary objective of this study was to describe the distribution of the Sunnybrook Facial Grading System scores in the general population. Secondary objectives included analyzing the effects of age, gender and facial side on these scores. Two speech therapists specializing in facial motor skill assessment evaluated the healthy participants using the Sunnybrook Facial Grading System, first with the right hemiface as a reference and then with the left hemiface as a reference. The study was conducted in our ENT department from September 2022 to June 2023. One hundred eleven healthy participants were included (57 women and 54 men), aged 18 to 79 years. SFGS composite scores (SFGS-Total) and sub-scores at rest (SFGS-Rest) and in movement (SFGS-Movement) were studied according to three age categories (18-39 years) (40-59 years) and (60-79 years) and gender. Inter-rater reliability was collected between the two evaluators with Cronbach's alpha. Taking the right hemiface as a reference, SFGS-Total scores ranged from 65% to 100% (median = 96, IQR [91-100]). When the left hemiface was considered as the reference, scores ranged from 78% to 100% (median = 95; IQR [90-100]). Right and left SFGS-Total scores showed high inter-rater reliability (respectively α = 0.953 and α = 0.926). There was a slight negative correlation between age and SFGS-Total scores. By embracing a more realistic approach that acknowledges natural variations and asymmetry in facial movements, we can enhance patient care and promote a more holistic understanding of facial rehabilitation outcomes.