Determining the conduction latency (C.L.) is one of the most popular diagnostic tools in facial palsy. Frequently it is helpful to measure the latencies of both affected and sound sides and compare the values obtained.

The purpose of this study is to see whether the C.L. of the sound side in facial palsy falls within the range of the normal. If so, the values could be used as the normal values until those of normal persons are published. As yet we do not have these values in Korea.

The mean with its range is studied and comparison between male and female, left and right is made.

The results are as follow;

1. The ratio of male female is 1.8:1 (115:63) in the orbicularis oris and 1.8:1 (100:57) in the orbicularis oculi.

2. The ratio of left to right is 1:1.2 (82:16) in the orbicularis oris and 1:1.2 (73:84) in the orbicularis oculi.

3. The mean C.L. of the orbicularis oris is 2.97±0.35 msec (2.2-4.0 msec).

4. The mean C.L. of the orbicularis oculi is 2.70±0.28 msec (2.0-3.6 msec).

5. The difference between male and female is statistically significant.

6. The difference between left and right is statistically insignificant.

Keywords :Facial palsy, Nerve conduction study, Latency