Sunnybrook Facial Grading System: Resting Symmetry, Dynamic Excursion, and Synkinesis Scoring
In short
The Sunnybrook Facial Grading System yields a continuous 0 to 100 composite score by evaluating resting symmetry, voluntary movement, and synkinesis. Discover its clinical value in facial rehabilitation.
In this guide (4 sections)
The Sunnybrook Facial Grading System (SFGS) is an internationally validated, sensitive clinical tool designed to overcome the limitations of single-number global scales. By separating assessment into three distinct components: resting symmetry, dynamic voluntary excursion, and synkinesis severity, the SFGS calculates a composite score ranging from 0 (complete flaccid paralysis) to 100 (normal function). This continuous numerical metric makes it exceptionally valuable for charting incremental recovery and evaluating the efficacy of targeted neuromuscular retraining.
Domestic Realities and Environmental Safeguards in India
In India, patients recovering from facial palsy often struggle during meals with family members, where chewing fibrous vegetables or rotis causes embarrassing involuntary eyelid blinking or cheek biting. During religious rituals, festival celebrations, and office meetings, individuals often attempt to overcompensate by smiling forcefully, which triggers pronounced oral-ocular synkinesis. A detailed Sunnybrook score helps the physiotherapist pinpoint exact co-contraction triggers and educate family members that low-amplitude, controlled expressions yield superior long-term control compared to forceful grimacing.
Component Weighting and Mathematical Scoring Structure
The Sunnybrook scoring system begins with resting symmetry (weighted score from 0 to 20, derived from eye, cheek, and mouth alignment). Dynamic symmetry assesses five standard facial expressions: forehead wrinkle (frontalis), gentle eye closure (orbicularis oculi), open mouth smile (zygomaticus major), lip snarl (levator labii superioris), and lip pucker (orbicularis oris), generating an excursion score from 20 to 100. Finally, synkinesis is scored across the same five standard movements (0 to 15 points). The composite score is calculated using the formula: Composite Score = Voluntary Movement Score minus Resting Symmetry Score minus Synkinesis Score. This penalizes secondary aberrant nerve sprouting and resting facial droop.
Targeting Synkinesis Sub-Scores Through Neuromuscular Retraining
When the Sunnybrook assessment reveals a rising synkinesis score despite improving voluntary movement, physiotherapists immediately modify the intervention strategy. Rather than continuing with non-specific active exercises, the clinician initiates strict mirror biofeedback. The patient is trained to maintain submaximal contractions (below 30 percent maximal voluntary effort) to preserve isolated motor firing without activating cross-wired collateral branches. If platysma banding or oral-ocular narrowing is identified, soft tissue release and slow eccentric lengthening of the hyperkinetic antagonist muscles are prioritized.
Submaximal Selective Smiling with Eyelid Aperture Control
Objective: Activate the zygomaticus major while suppressing involuntary orbicularis oculi co-contraction
- 1Position yourself comfortably before a mirror at eye level with adequate overhead lighting.
- 2Rest your fingertips lightly on your lower eyelid margins on both sides to provide tactile biofeedback.
- 3Initiate a very subtle, gentle smile, elevating the corner of your mouth by only 2 to 3 millimeters.
- 4Concentrate on keeping the affected eye wide open and completely relaxed without narrowing the palpebral fissure.
- 5Hold the gentle, symmetric mouth elevation for 3 seconds, then slowly release over 3 seconds without twitching.
| Evaluation Domain | Specific Anatomical Regions Tested | Clinical Scoring Scale and Calculation Impact |
|---|---|---|
| Resting Symmetry | Palpebral fissure width, nasolabial fold depth, corner of mouth position. | Scored as normal (0), wide/deep/high (1), or narrow/flat/low (2). Multiplied by 5. Subtracted from total. |
| Voluntary Movement | Forehead wrinkle, gentle eye closure, open smile, snarl, lip pucker. | Scored from 1 (unable to initiate) to 5 (complete movement). Multiplied by 4. Forms base positive score (20-100). |
| Synkinesis Severity | Involuntary muscle twitching or contraction observed during the 5 voluntary expressions. | Scored as none (0), mild (1), moderate (2), or severe (3). Multiplied by 1. Subtracted from total. |
| Composite Final Score | Comprehensive facial functional status combining dynamic, static, and aberrant vectors. | Formula: Voluntary Movement Score minus Resting Symmetry Score minus Synkinesis Score (0 to 100 scale). |
If a patient demonstrates an increasing Sunnybrook synkinesis score during consecutive evaluations, aggressive facial strengthening exercises must be halted immediately. Persisting with high-effort grimacing reinforces aberrant axonal misdirection and cements permanent involuntary co-contractions.
Frequently Asked Questions
How often should a Sunnybrook Facial Grading assessment be repeated?
In the acute and subacute recovery stages, reassessment every 2 to 4 weeks provides clear evidence of axonal regeneration and early synkinesis. In chronic rehabilitation or during botulinum toxin management cycles, serial scoring at 6 to 12-week intervals allows objective titration of physiotherapy interventions.
Can I access certified facial rehabilitation physiotherapists directly under Indian regulations?
Yes. Under the National Commission for Allied and Healthcare Professions (NCAHP) Act 2021, patients in India can consult registered physiotherapists directly without third-party medical prescriptions. BookPhysio.in enables direct clinic or home-visit appointment booking with pay-per-session pricing and zero subscription costs.
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The BookPhysio.in editorial team writes and maintains this content, checking it against reliable clinical sources. Content follows our medical review policy: general information only, and no page claims a clinical review until a named registered physiotherapist has signed it off.
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