Non-Randomized Trial of Bruxism-Related TMD Treatments

Comparative Evaluation of Occlusal Splint Therapy, Botulinum Toxin Type A Injection, and Combined Medical-Splint Therapy in Bruxism-Related Temporomandibular Disorder Symptoms: A Prospective Non-Randomized Open-Label Controlled Trial

This study compares three treatment approaches for adults with bruxism-related temporomandibular disorder symptoms: occlusal splint therapy, botulinum toxin type A injection, and combined medical-splint therapy. Participants were assigned to one of three non-randomized treatment arms according to clinical indication, symptom profile, shared decision-making, and patient preference. Symptom severity was assessed before treatment and after 3 months using the Fonseca Anamnestic Index. The primary purpose of the study was to compare the 3-month change in total Fonseca Anamnestic Index scores among the treatment arms. Selected symptom items and treatment-related adverse events were also evaluated during follow-up.

Study Overview

• Status: Completed
• Conditions: Bruxism; Myofascial Pain; Temporomandibular Disorders (TMD)
• Intervention / Treatment: Device: Occlusal splint; Drug: Botulinum Toxin Type A (Dysport®); Drug: Thiocolchicoside; Drug: tenoxicam

Detailed Description

This is a prospective, non-randomized, open-label, controlled, parallel-arm clinical trial evaluating treatment outcomes in patients with bruxism-related temporomandibular disorder symptoms. A total of 60 adult participants were assigned to one of three treatment arms: occlusal splint therapy, botulinum toxin type A injection, or combined medical-splint therapy.

Participants in the occlusal splint arm received custom-made maxillary stabilization splints and were instructed to use the splints during sleep. Participants in the botulinum toxin type A arm received a single session of intramuscular injections into the masseter and temporalis muscles. Participants in the combined medical-splint arm received a maxillary stabilization splint together with a short-term pharmacological regimen for acute symptom control.

The Fonseca Anamnestic Index was administered at baseline and at the 3-month follow-up. The primary outcome was the change in total Fonseca Anamnestic Index score from baseline to 3 months. Secondary assessments included changes in selected Fonseca Anamnestic Index sub-item scores, changes in Fonseca Anamnestic Index severity categories, and monitoring of treatment-related adverse events. Because of the nature of the interventions, participants and clinicians were not blinded to treatment assignment.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Phase 4

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Rize Province
    • Rize, Rize Province, Turkey (Türkiye), 53020
      • Recep Tayyip Erdogan University Faculty of Dentistry

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Adults aged 18 years or older.
• Presence of bruxism-related temporomandibular disorder symptoms.
• Self-reported sleep or awake bruxism based on clenching or grinding awareness.
• Clinical signs compatible with bruxism, including dental attrition, cupped-out wear facets, or shiny occlusal surfaces.
• Absence of known systemic conditions that could interfere with treatment or outcome assessment.
• Ability to provide written informed consent.

Exclusion Criteria:

• Age younger than 18 years.
• Presence of systemic or neurological disorders.
• Uncontrolled psychiatric conditions.
• Infection or inflammatory lesions at the planned injection sites.
• History of maxillofacial surgery or severe trauma in the relevant orofacial region.
• Inability or unwillingness to provide written informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Occlusal Splint Therapy; Participants in this arm received custom-made maxillary stabilization splints. The splints were adjusted to obtain simultaneous bilateral posterior contacts in centric relation and canine guidance during eccentric movements. Participants were instructed to wear the splints during sleep for at least eight hours per night for 3 months.	Device: Occlusal splint; Custom-made maxillary stabilization splints were fabricated from hard acrylic resin and adjusted to obtain simultaneous bilateral posterior contacts in centric relation and canine guidance during eccentric movements. Participants were instructed to wear the splints during sleep for at least eight hours per night.; Other Names: Maxillary stabilization splint; Hard acrylic stabilization splint
Active Comparator: Botulinum Toxin Type A Injection; Participants in this arm received a single session of intramuscular botulinum toxin type A injections. Dysport was reconstituted with 2 mL sterile 0.9% saline. A total dose of 160 U Dysport was administered per participant, consisting of 60 U into each masseter muscle and 20 U into each temporalis muscle.	Drug: Botulinum Toxin Type A (Dysport®); Botulinum toxin type A was administered as a single intramuscular injection session. Dysport was reconstituted with 2 mL sterile 0.9% saline. A total dose of 160 U Dysport was administered per participant, consisting of 60 U into each masseter muscle and 20 U into each temporalis muscle.
Experimental: Combined Medical-Splint Therapy; Participants in this arm received a custom-made maxillary stabilization splint using the same design and adjustment protocol as the splint arm. In addition, a short-term pharmacological regimen consisting of thiocolchicoside 8 mg/day and tenoxicam 20 mg/day was prescribed for 7 to 10 days for acute symptom control. Participants continued nocturnal splint use during the follow-up period.	Device: Occlusal splint; Custom-made maxillary stabilization splints were fabricated from hard acrylic resin and adjusted to obtain simultaneous bilateral posterior contacts in centric relation and canine guidance during eccentric movements. Participants were instructed to wear the splints during sleep for at least eight hours per night.; Other Names: Maxillary stabilization splint; Hard acrylic stabilization splint; Drug: Thiocolchicoside; Thiocolchicoside 8 mg/day was prescribed as part of a short-term pharmacological regimen for acute symptom control in the combined medical-splint therapy arm. The medication was used for 7 to 10 days.; Drug: tenoxicam; Tenoxicam 20 mg/day was prescribed as part of a short-term pharmacological regimen for acute symptom control in the combined medical-splint therapy arm. The medication was used for 7 to 10 days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Total Fonseca Anamnestic Index Score	Change in total Fonseca Anamnestic Index score from baseline to the 3-month follow-up. The change score was calculated as pre-treatment total score minus post-treatment total score. Higher positive values indicate greater symptom improvement.	Baseline to 3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Selected Fonseca Anamnestic Index Sub-Item Scores	Changes in selected Fonseca Anamnestic Index sub-item scores from baseline to the 3-month follow-up. The selected items assessed mouth opening difficulty, masticatory muscle fatigue or pain during chewing, temporomandibular joint clicking, and teeth clenching or grinding habit.	Baseline to 3 months
Change in Fonseca Anamnestic Index Severity Category	Change in categorical Fonseca Anamnestic Index severity classification from baseline to the 3-month follow-up. Total scores were categorized as absence of TMD-related symptoms, mild symptoms, moderate symptoms, or severe symptoms according to the Fonseca Anamnestic Index classification.	Baseline to 3 months
Treatment-Related Adverse Events	Occurrence of treatment-related adverse events during the 3-month follow-up period, including injection-site symptoms, chewing weakness, facial asymmetry, dysphagia, medication-related intolerance, splint-related discomfort, mucosal irritation, or occlusal changes. Serious adverse events were defined as events requiring urgent medical care, hospitalization, treatment discontinuation, or resulting in persistent functional impairment.	Up to 3 months

Collaborators and Investigators

• Sponsor: Recep Tayyip Erdogan University
• Investigators: Principal Investigator: Sedef KURT CIRALIK, Recep Tayyip Erdogan University, Faculty of Dentistry

Study record dates

Study Major Dates

• Study Start (Actual): August 5, 2024
• Primary Completion (Actual): August 1, 2025
• Study Completion (Actual): August 1, 2025

Study Registration Dates

• First Submitted: May 7, 2026
• First Submitted That Met QC Criteria: May 7, 2026
• First Posted (Actual): May 14, 2026

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 7, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Botulinum toxin type A; Occlusal splint; Fonseca Anamnestic Index; Medical-splint therapy; Masticatory muscle pain; Bruxism-related TMD symptoms; Temporomandibular disorder symptoms
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Stomatognathic Diseases; Muscular Diseases; Joint Diseases; Jaw Diseases; Tooth Diseases; Mandibular Diseases; Craniomandibular Disorders; Behavior; Habits; Bruxism; Temporomandibular Joint Disorders; Amino Acids, Peptides, and Proteins; Proteins; Biological Factors; Orthopedic Equipment; Surgical Equipment; Equipment and Supplies; Hydrolases; Enzymes; Enzymes and Coenzymes; Botulinum Toxins; Metalloendopeptidases; Endopeptidases; Peptide Hydrolases; Metalloproteases; Bacterial Proteins; Bacterial Toxins; Toxins, Biological; Orthotic Devices; Botulinum Toxins, Type A; abobotulinumtoxinA; Occlusal Splints; tenoxicam; thiocolchicoside
• Other Study ID Numbers: 1081 (Förderung, Forschung und Lehre der LMU;); 2024/194 (Other Identifier: Recep Tayyip Erdoğan University Institutional Ethics Committee)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data underlying the results reported in this study may be made available from the corresponding author upon reasonable request. Data will be shared only after review of the scientific purpose of the request and, where appropriate, completion of a data sharing agreement.
• IPD Sharing Time Frame: De-identified individual participant data and available supporting information will be made available beginning 6 months after publication and will be available for 5 years.
• IPD Sharing Access Criteria: De-identified individual participant data may be shared with qualified researchers for scientifically valid purposes upon reasonable request to the corresponding author. Requests will be reviewed by the study investigators, and data will be shared only after approval of the request and, where appropriate, completion of a data sharing agreement. Shared data will not include information that could directly identify participants.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No