EFFECTS OF BOTULINUM TOXIN (BTX) INJECTION ON PAIN INTENSITY, FUNCTIONAL RECOVERY, AND ORAL HEALTH–RELATED QUALITY OF LIFE IN PATIENTS WITH MYOFASCIAL PAIN DISORDER: A RANDOMIZED CONTROLLED TRIAL

Abstract

Myofascial Pain Disorder (MPD) is a chronic and debilitating musculoskeletal condition characterized by localized trigger points, persistent muscle tenderness, functional impairment, and reduced quality of life. Conventional treatment modalities often provide limited or temporary relief, particularly in refractory cases. This study aimed to evaluate the effectiveness of Botulinum Toxin (BTX) injection in reducing pain intensity and improving functional recovery and oral health–related quality of life among patients diagnosed with MPD. A prospective, randomized, double-blind, placebo-controlled clinical trial was conducted at a tertiary care hospital. Eligible participants were randomly assigned to receive either BTX injection or placebo. Pain intensity was assessed using the Visual Analog Scale (VAS), functional recovery using the Functional Independence Measure (FIM), and oral health–related quality of life through a validated questionnaire. Baseline characteristics were comparable between groups, with no statistically significant difference in initial pain scores (p = 0.52). Post-intervention analysis demonstrated significant reductions in pain intensity and significant improvements in functional performance and quality of life in the BTX group compared to placebo (p < 0.05). The magnitude of improvement suggests both clinical and statistical relevance. These findings support the neuromuscular inhibitory mechanism of BTX and indicate that it may serve as an effective adjunctive therapy in the multimodal management of chronic myofascial pain. Further large-scale studies with longer follow-up periods are recommended to confirm long-term efficacy and optimize treatment protocols