Peripheral TMD Pain Mechanisms and the Effect by Botulinum Toxin A. A Randomized, Controlled, Double-blind Study

What this Trial Is About

Researchers are investigating how botulinum toxin affects nerve cell plasticity in the masseter muscle of women aged 20 to 45 with painful myogenous temporomandibular disorders (TMDM). The study aims to understand if botulinum toxin changes gene expressions, epigenetic markers, and cell plasticity in these muscles and whether these changes differ between local and regional TMDM. It also evaluates how treatment influences pain characteristics like intensity, frequency, and sensitivity, looking for correlations with biomarker changes. Participants will be randomly assigned to receive either botulinum toxin or isotonic saline injections. The active treatment group receives 100 IU of botulinum toxin divided among five points on the masseter and temporalis muscles, guided by EMG to ensure accurate muscle injection. The control group receives saline injections in the same manner. The study includes a screening visit with questionnaires, clinical examination, sensory testing, and muscle biopsies before treatment. Follow-up visits occur at one, three, and six months to collect further biopsies, assess pain, and measure molecular changes. Participants will complete detailed questionnaires on physical and emotional health and undergo clinical exams including quantitative sensory testing. Muscle biopsies from painful and non-painful sites are collected before and after treatment to analyze gene expression, protein changes, and neuron markers using advanced laboratory techniques. Researchers will track pain intensity, global improvement, and physical and emotional function over time. Safety is monitored through adverse event questionnaires. The total study duration for each participant spans six months, allowing comprehensive evaluation of treatment effects and biological markers.

Peripheral TMD Pain Mechanisms and the Effect by Botulinum Toxin A