Grade I: Normal. Normal facial muscle movement in all regions. Grade II: Mild functional abnormalities. Gross: Mild facial muscle weakness on close examination, may have very light joint band movements. Resting state: symmetrical face with normal muscle tone. Motor: normal frontal area, complete eye closure with slight force, mild asymmetry of the corners of the mouth. Grade III: moderate functional abnormalities. Gross: obvious facial muscle weakness, but no facial deformation, significant joint band movement or hemifacial spasm. Resting state: symmetrical face with normal muscle tone. Motor: frontal diminished, complete eye closure after force, mild asymmetry in the corners of the mouth after using maximum force. Grade IV: moderate to severe functional abnormalities. Gross: marked facial muscle weakness and/or facial deformation. Resting state: facial symmetry with normal muscle tone. Motor: no frontal, incomplete eye closure, and asymmetry in the corners of the mouth after using maximum force. Grade V: severe functional abnormalities. Gross: only barely perceptible facial movements. Resting state: asymmetry of the face. Movement: absent in the frontal region, incomplete eye closure, slight movement in the corners of the mouth. Grade VI: complete paralysis with no movement.