A comparison of the masseteric silent period in temporomandibular joint dysfunction and normal human subjects by surface electromyography and single motor-unit recordings

Characteristics of a jaw reflex in humans with temporomandibular disorders: a preliminary report

“…The decreased duration of this inhibitory period in the TMD group is again in agreement with the previous studies (11, 20, 13). Curiously, Sharav et al.…”

“…The general finding that reflex masseter inhibitions were weaker or absent in TMD patients is in keeping with previous similar studies (11, 13, 20, 23). The analysis of reflex thresholds was made difficult by the fact that not all the subjects would tolerate the top multiple of sensory threshold (10T) because the pain caused by the test stimulus became intolerable at lower intensities.…”

“…If that finding is mirrored in the trigeminal situation -and these inhibitory jaw reflexes are often viewed as being the trigeminal equivalent to flexion withdrawal (25) -then this would eliminate the concern that the likely reflex threshold was not being reached. The absence of a significant difference in reflex threshold between the two general groups is not a surprise as it mirrors the findings of Sharav et al (11) and Tü rker et al (13) when studying intra-orally evoked reflexes. A general trend towards a difference (but not a significant difference) being present when the TMD patients were in pain compared with the controls was in agreement with Sharav and his colleagues.…”

“…(11) and Türker et al. (13) when studying intra‐orally evoked reflexes. A general trend towards a difference (but not a significant difference) being present when the TMD patients were in pain compared with the controls was in agreement with Sharav and his colleagues.…”

Masseter reflexes modulated by pain

“…The latter finding is in agreement with the observation of a more robust configuration of the early inhibitory period (ES1, 15‐msec latency) than the late inhibitory period (ES2, 45‐msec latency) after electrical stimulation of the facial or perioral skin in patients with persistent jaw‐muscle pain. This finding has also been found in recordings of single motor units of patients with TMD pain where the early inhibitory period, as revealed in the cumulative sum displays, was more prominent and resistant to changes in the prestimulus firing frequency than in the control group 4. However, the same characteristics were true for the late inhibitory period in control subjects.…”