Evaluation and Grading Systems of Facial Paralysis for Facial Rehabilitation

[Purpose] We investigated the availability of facial grading systems for the evaluation of facial nerve functions including both of traditional and computer-based approaches. An accurate and reliable studies on facial grading systems is needed for constructing a standard system, which is desired by the medical professions all over the world, for evaluating how much the patients suffering from facial paralysis. [Methods] We searched for articles related to facial grading systems using online databases such as Pub Med, Elsevier, IEEE, Springer, and the ACM digital library. Studies selected to be include were based on following criteria: a) in English language; b) published from 1955 to 2012; and c) considered both bilateral and unilateral facial palsy resulting from any causes. [Results] Thirty-two articles were identified in the search, and we present an overview and explanations of various traditional and computer-based methods for accessing facial nerve function for facial rehabilitation. [Conclusion] Studies of facial grading systems cannot be compared easily as facial grading systems have their own advantages and disadvantages. We expect that this review will provide the clinicians and researchers a brief overview of the facial grading systems which have been used and assist in the development of a standard one.