Triazolam improves sleep but fails to alter pain in TMD patients

Patients with chronic orofacial pain often report disturbances in sleep, leading to the hypothesis that nocturnal motor hyperactivity of the muscles of mastication may contribute to the nociceptive process. This hypothesis was tested in a controlled study to evaluate the relationship between sleep stages, patient self-report of pain in the orofacial region, and nocturnal masticatory muscle activity. Twenty subjects participating in a two-period, within-subject, crossover study received triazolam or placebo for 4 nights. Sleep, pain, and mandibular range of motion were assessed at baseline, following the first period, and again following the second period; a 3-day washout period separated the two treatments. Subjective report of sleep quality was significantly improved following triazolam in comparison to placebo as measured by category scales for sleep quality, restfulness, and sleep compared to usual. The amount of time spent in stage-2 sleep was also significantly increased by triazolam. No improvement was seen in pain as measured by palpation with an algometer, in scales for sensory intensity and the affective component of pain, or in daily pain diaries. Mean facial muscle electromyographic activity for 30-second epochs averaged over the entire period of sleep did not reveal any differences in muscle activity across the three conditions. These data indicate that improvements in sleep quality and alterations in sleep architecture do not affect nocturnal facial muscle activity or subsequent pain report in temporomandibular patients, thereby failing to support the hypothesized relationship between sleep disturbances and chronic orofacial pain.