Efficiency of Botulinum Toxin type-a in the Management of the Myofascial Pain

Investigation of the Relationship Between Clinical Results of Onabotulinum Toxin A Application and Pain Mediators in the Treatment of Myospasm-Related Masticatory Muscle Disorder

**Study Title:** Investigation of the Relationship Between Clinical Outcomes and Pain Mediators in the Treatment of Masticatory Muscle Disorders Associated with Myospasm Using Onabotulinum Toxin A

**Study Importance:** Temporomandibular disorders (TMD) are a major cause of chronic orofacial pain, affecting 5-12% of the population. Masticatory muscle disorders (MMD) are a common subgroup of TMD, ranging from localized myalgia to fibromyalgia. Myospasm is characterized by sudden pain, malocclusion, and limited jaw movement, while myalgia includes localized, myofascial, and referred pain patterns. The etiology of MMD is complex, involving neuromuscular dysfunction, inflammation, and increased acetylcholine activity at the neuromuscular junction. Various mediators, including CGRP, substance P, and inflammatory cytokines, play a role in sensitization and pain perception.

**Objective:** This study aims to evaluate the effectiveness of onabotulinum toxin A (BTX-A) in patients with MMD who have not responded to conventional non-invasive treatments. This exploratory study investigates whether BTX-A is associated with reductions in pain and inflammatory cytokines and neuropeptides.

**Methodology:**

• **Study Design:** Prospective observational clinical study.
• **Participants:** Patients diagnosed with MMD based on DC/TMD criteria, who have not improved with conventional treatments.
• **Exclusion Criteria:**1) pregnancy or lactation; 2) use of oral contraceptives; 3) history of radiotherapy, active chemotherapy, or trauma in the maxillofacial region; 4)uncontrolled metabolic or systemic diseases; 5)active infections; allergic tendencies; significant tooth loss; 6) rheumatic diseases or other TMJ-defined disorders; 7) use of antidepressants or anti-inflammatory agents within the past week; 8) neuromuscular disorders (e.g., myasthenia gravis, Eaton-Lambert syndrome); 9) planned surgical procedures in the near future, 10) individuals undergoing concomitant therapies.
• **Intervention:** BTX-A will be injected into the masseter and temporalis muscles (30 and 15 units per side, respectively) following a standardized protocol.
• **Data Collection:**
• Before (T0) and 28 days after (T1) treatment.
• Clinical assessments include maximum mouth opening (MMO), pain levels (VAS), pain pressure threshold and oral health impact profile (OHIP-14).
• Blood and saliva samples will be analyzed for IL-1, IL-6, TNF-α, CGRP, and NGF using ELISA.
• **Statistical Analysis:** Dependent t-test or Wilcoxon signed-rank test will be used to compare pre- and post-treatment values. Correlations between biomarker levels and pain reduction will be analyzed using Spearman correlation.

**Expected Outcomes:**

• Significant reduction in pain and improvement in MMO.
• Decreased levels of inflammatory and neuropeptide biomarkers.
• Evaluation of saliva as a non-invasive medium for biomarker analysis, potentially guiding future diagnostic and monitoring strategies.

**Significance:** This study provides insights into the pathophysiology of MMD and the efficacy of BTX-A in pain management, potentially offering an alternative therapeutic approach for patients resistant to conventional treatments.

Study Overview

• Status: Completed
• Conditions: Myofascial Pain - Dysfunction Syndrome of TMJ
• Intervention / Treatment: Drug: Botulinum Toxin A (Botox )

• Study Type: Interventional
• Enrollment (Actual): 25
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Ankara, Turkey (Türkiye)
    • Hacettepe University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria: Patients diagnosed with MMD based on RDC/TMD criteria, who have not improved with conventional treatments.

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Exclusion Criteria:Conditions such as pregnancy, metabolic disorders, trauma, systemic diseases, and medication use that could interfere with results

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Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: botulinum toxin; TX-A will be injected into the masseter and temporalis muscles (30 and 15 units per side, respectively) following a standardized protocol.	Drug: Botulinum Toxin A (Botox ); TX-A will be injected into the masseter and temporalis muscles (30 and 15 units per side, respectively) following a standardized protocol.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Pain Intensity	Change in pain intensity measured using the Visual Analog Scale (VAS). The VAS is a 10-cm scale ranging from 0 (no pain) to 10 (worst imaginable pain). Higher scores indicate greater pain intensity..	Baseline and 28 days after injection

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Salivary and Serum Inflammatory Biomarker	Change in salivary and serum concentrations of calcitonin gene-related peptide (CGRP), nerve growth factor (NGF), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-α). Biomarker levels will be quantified using enzyme-linked immunosorbent assay (ELISA) and expressed in picograms per milliliter (pg/mL). Higher concentrations indicate increased inflammatory activity. These biomarkers will be evaluated to explore potential mechanistic pathways underlying the clinical effects of Botulinum Toxin Type A.	Baseline and 28 days after injection
Change in Maximum Mouth Opening	Change in maximum mouth opening (MMO), measured in millimeters (mm) as the maximum interincisal distance without assistance. Higher values indicate improved mandibular function.	Baseline and 28 days after injection
Change in Oral Health-Related Quality of Life	Change in Oral Health Impact Profile-14 (OHIP-14) score. The OHIP-14 is a validated questionnaire with scores ranging from 0 to 56, where higher scores indicate poorer oral health-related quality of life.	Baseline and 28 days after injection
Change in Pressure Pain Threshold	Change in pressure pain threshold (PPT) measured using an algometer at the masseter and temporalis muscles. Values are recorded in kilograms per square centimeter (kg/cm²). Higher values indicate increased pain tolerance.	Baseline and 28 days after injection

Collaborators and Investigators

• Sponsor: Hacettepe University

Study record dates

Study Major Dates

• Study Start (Actual): June 3, 2024
• Primary Completion (Actual): January 12, 2025
• Study Completion (Actual): April 13, 2025

Study Registration Dates

• First Submitted: February 13, 2025
• First Submitted That Met QC Criteria: February 18, 2025
• First Posted (Actual): February 21, 2025

Study Record Updates

• Last Update Posted (Actual): February 18, 2026
• Last Update Submitted That Met QC Criteria: February 16, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Stomatognathic Diseases; Muscular Diseases; Joint Diseases; Jaw Diseases; Mandibular Diseases; Craniomandibular Disorders; Temporomandibular Joint Disorders; Amino Acids, Peptides, and Proteins; Proteins; Biological Factors; Hydrolases; Enzymes; Enzymes and Coenzymes; Botulinum Toxins; Metalloendopeptidases; Endopeptidases; Peptide Hydrolases; Metalloproteases; Bacterial Proteins; Bacterial Toxins; Toxins, Biological; Botulinum Toxins, Type A
• Other Study ID Numbers: KA-23004

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No