BACKGROUND: The Sunnybrook Facial Grading System is considered one of the best 
scales available to grade facial motility and postparetic synkinesis. To measure 
facial landmarks and movement excursion, a new software, the Facial Assessment 
by Computer Evaluation, has been proposed. The aim of this study was to quantify 
eye synkinesis improvement after botulinum toxin type A injections using the new 
software and to compare this method with the Sunnybrook grading system.
METHODS: The study included 40 injection sessions on 29 Caucasian outpatients 
with facial synkinesis. Before and 2 weeks after the injection, patients were 
evaluated using the Italian version of the Sunnybrook system. Eyelid fissure 
size at rest, during lip puckering, and while smiling was measured with the new 
software.
RESULTS: After botulinum infiltration, the Sunnybrook grading system showed a 
global facial improvement with reduction of synkinesis and increase of static 
and dynamic symmetry. The Facial Assessment software detected an increase of 
ocular fissure measure at rest, during lip puckering, and especially during 
smiling, and the improvement was positively correlated with initial asymmetry. A 
single point of the Sunnybrook system synkinesis score corresponded to a mean 
difference of 0.77 mm during smiling and 1.0 mm during lip puckering.
CONCLUSIONS: The Facial Assessment by Computer Evaluation measure allowed the 
authors to quantify the improvement of eye synkinesis after botulinum toxin type 
A injection. The Sunnybrook Facial Grading System provided an immediate 
instrument with which to monitor treatment in routine clinical practice, whereas 
the Facial Assessment system gave a more accurate quantitative assessment.
CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, II.