Method: N=71 from pharmacy records. All had received Botox injections in the temporalis and masseter bilaterally. The records were reviewed to look for 1) medical/psychiatric comorbidities, 2) clinical findings, diagnosis and adjunct therapy, and 3) subjective responses to Botox therapy. Chi-square tests were used to compare those with and without the above variables.
Result: 77% of the patients reported beneficial effects of Botox. Patients with bruxism, occlusal splint, joint pain, myofascial pain, fibromyalgia, degenerative joint disease, or stress-related psychiatric comorbidity (SRPC) were more likely to report beneficial effects of Botox than those who did not (bruxism p = 0.042). If the time between the initial Botox injection and the follow-up was less than 5 weeks, then the patients were less likely to observe improvements (p = 0.009).
Conclusion: Botox is an effective pain management option for patients who have TMD and associated myofascial pain, and the effect should be evaluated no earlier than 5 weeks post-injection.
Future Studies: We intend to conduct a controlled clinical trial to investigate the efficacy of Botox in the treatment of TMD in patients with a diagnosis of post-traumatic stress disorder (PTSD). Since temporomandibular and myofascial pain may be a trigger for PTSD symptoms, we will also study whether Botox is effective in reducing the severity of PTSD itself by observing a change in the central mechanism using fMRI.