Influence of auriculotemporal nerve anaesthesia on the masseteric silent period

Silent periods were evoked from the masseter muscles bilaterally in response to chin taps during a clench. Injection of 0.75 ml of 3% Mepivicaine posteromedial to each condyle led to a distribution of skin anaesthesia consistent with the distribution of the auriculotemporal nerve. Silent periods were evoked prior to and during anaesthesia in ten subjects. The silent period latencies (mean ± standard deviation) prior to anaesthesia were 12.5 ± 1.8 ms and 11.9 ± 2.5ms in the right and left masseters. During anaesthesia the latency decreased by 0.3 ± 1.3 ms in the right masseter and by 0.3 ± 2.1 ms on the left masseter. Neither change was statistically significant (P > 0.05). The silent period durations prior to anaesthesia were 20.3 ± 4.0 ms and 22.8 ± 7.1 ms in the right and left masseters. During anaesthesia, these decreased by 2.74 ± 5.8 ms on the right and 2.15 ± 4.4 ms on the left. These decreases were not statistically significant (P > 0.05). These results failed to demonstrate an influence of the predominant nerve supply of the TMJ on either the latency or the duration of the masseteric silent period.