Outcomes of Treating Myofascial Pain by Injecting Masseter and Temporalis Muscles with Botulinum Toxin

Botulinum toxin (BTX) injections have gained great attention for the management of myofascial pain involving the masticatory muscles as alternative or complementary to other treatments. The objective is to evaluate how effective the botulinum toxin injections in reducing myofascial pain of the masseter and temporalis muscles through assessing pain changes over time and factors influencing treatment outcomes.

A prospective clinical study was conducted between January 2019 and November 2024 in Basrah, Iraq. The number of patients to be enrolled was the 320 patients who had myofascial pain and 200 patients had completed the follow-up. Pain intensity was measured on a pain scale at baseline and structural follow-ups on an interval of several follow-ups following botulinum toxin injection on masseter and temporalis muscle tender points.

The mean pain scores were lower at two years of follow up as compared to the baseline of 7.99 with a standard deviation of 0.79, which had reduced to 3.87 with a standard deviation of 1.53. The highest reduction of pain was experienced during the early follow up but it was sustained. At 8 weeks, younger patients (2635 years) had lower pain scores. There was a small difference in genders and more pain reduction was experienced by married patients. The increased income and education level was correlated with a low score of pain in the early follow-up. But the differences decreased by the two year assessment.

The effects of Botulinum toxin injections are a large and long-lasting decrease in myofacial pains of the masseter and temporalis muscles. Early pain reaction may depend on demographic and socio-economic factors, but the long-term results seem to be similar.