Objective
To obtain the mean value of parameters of the jaw jerk and to investigate gender difference on the jaw jerk in normal young adults in Korea.

Method
In young 40 subjects (20 males and 20 females), the jaw jerks were elicited by chin tapping in the relaxed masseter muscles of both sides.

Results
The jaw jerks were recorded in 100% of the total number of chin-taps. The mean latency was 5.39 ms in the males and 5.14 ms in the females (p＞0.05). The mean amplitude was 0.75 mV in the males and 0.59 mV in the females (p＞0.05). The mean duration was 8.18 ms in the males and 7.85 ms in the females (p＞0.05).

Conclusion
No significant differences were found in the parameters of the jaw jerk between males and females in this study.