I. Introduction
Facial palsy is a disease caused by neural damage of the face. The patient is usually paralyzed or decreased ability of movement of their face on one side. Although they can recover from the condition, some sequelae may be left if the disease is not treated early and properly. For an effectiveness of treatment, a quantitative evaluation of the disease has to be performed so that the approximate treatment method [1] can be applied accordingly. In Japan, the Yanagihara grading system (YGS) [2] is largely used for medical diagnostics of facial palsy. In the YGS, for the patient, there are ten expressions to be required to perform. Each expression is assigned a score of 0 point (pt) for full palsy, of 2 (pts) for partial palsy, or of 4 (pts) for normal depending on how serious condition. The assignment of score from clinician is based on clinical observation and experience of clinicians. The total score for ten expressions is used for general diagnosis. A person is considered as a normal if he or she has the total score in the range from 36 (pts) to 40 (pts). Conversely, a patient is considered as a full palsy if he or she has the total score in the range from 0 (pts) to 8 (pts). Table I enumerates 10 expressions of YGS and approximate scores corresponding to serious levels of facial paralysis disease. Yanagihara grading system
Denote | Expression | Evaluation Score | ||
---|---|---|---|---|
Normal | Partial palsy | Full palsy | ||
EP0 | No expression | 4 (pts) | 2 (pts) | 0 (pts) |
EP1 | Raising eyebrows | |||
EP2 | Closing eyes gently | |||
EP3 | Closing eyes tightly | |||
EP4 | Closing one eye | |||
EP5 | Screwing up nose | |||
EP6 | Puffing out cheeks | |||
EP7 | Moving toothy | |||
EP8 | Whistling | |||
EP9 | Turning down under lip |