The effectiveness of adding pharmacologic treatment with clonazepam or cyclobenzaprine to patient education and self-care for the treatment of jaw pain upon awakening: a randomized clinical trial.
To compare the relative effectiveness of a benzodiazepine (clonazepam), a muscle relaxant (cyclobenzaprine), and a placebo for the treatment of jaw pain upon awakening, when each is combined with the recommended nonpharmacological components of initial medical management.
                Forty-one subjects were recruited with a diagnosis of myofascial pain based on the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). All subjects were given education about TMD and a self-care program. Subjects were randomized into 1 of 3 groups: clonazepam (0.5 mg/night), cyclobenzaprine (10 mg/night), or placebo. The primary outcome measure was the subjects' average intensity of jaw pain upon awakening over the prior week. This was recorded with a visual analog scale at pretreatment and at the completion of the 3-week trial. A secondary outcome measure was sleep quality based on the Pittsburg Sleep Quality Index.
                Within-group changes showed a statistically significant (P < .001) decrease in jaw pain upon awakening for all 3 groups. Between-group differences demonstrated a statistically significant difference (P < .016) between cyclobenzaprine and placebo, and between cyclobenzaprine and clonazepam. There was no significant effect on sleep quality in any group.
                This study suggests that cyclobenzaprine is statistically superior to either placebo or clonazepam when added to self-care and education for the management of jaw pain upon awakening. Based on the subjects' report of sleep quality, these medications failed to significantly improve sleep in the short term.
There was insufficient evidence to support the use of cyclobenzaprine in the treatment of MP. We identified only two small studies in which a total of 35 participants were given cyclobenzaprine, and it was not possible to estimate risks for benefits or harms. Further high quality RCTs of cyclobenzaprine for treating MP need to be conducted before firm conclusions on its effectiveness and safety can be made. Experts in this area should elect cut-off points for participants to identify whether a patient has achieved a clinically relevant reduction of pain (primary outcome), so that their results can be combined easily into future versions of this review.