Quantitative assessment of the variation within grades of facial paralysis.

A completely objective, unambiguous outcome measure of facial function is now available. A new automated computer-assisted clinimetric system combines the crucial detection capabilities of the human observer and the unique capacity of the computer to quantify the image light reflectance difference observed during facial expression. The new system was applied to 27 patients with a variety of diseases affecting the facial nerve. All subjects could be individually and objectively ranked, and disease-specific profiles could be constructed. These tasks are not possible with the House-Brackmann scale, because of the wide variation within grades and the ambiguity between grades. With the automated objective, unambiguous outcome measure, it may be possible to define individual case progression, recovery, and outcome over the course of disease.