Botulinum Toxin-A for Bruxism Using Digital Occlusal Analysis

Objective Assessment of Bruxism and Treatment Response Using Digital Occlusal Analysis: A Clinical Study of Botulinum Toxin-A

Bruxism is a repetitive jaw-muscle activity that may lead to tooth wear, muscle pain, headaches, and functional limitations. Current diagnostic approaches mainly rely on self-reported symptoms and clinical examination findings, which may not accurately reflect ongoing muscle activity. Digital occlusal analysis systems offer an objective method for evaluating bite force and occlusal function.

The aim of this randomized, placebo-controlled clinical trial is to investigate whether a digital occlusal analysis system can objectively assess bruxism and monitor treatment response following Botulinum Toxin-A (BTX-A) injections. Thirty-six adults diagnosed with bruxism will be randomly assigned to receive either BTX-A injections or placebo injections into the masseter muscles.

Clinical examinations, patient-reported outcomes, and digital occlusal measurements will be collected at baseline and at 2 weeks, 3 months, and 6 months after treatment. Primary outcomes include bite force characteristics, force distribution, occlusion time, disocclusion time, and center of force. Secondary outcomes include pain intensity, maximum mouth opening, muscle tenderness, functional limitation scores, and self-reported bruxism-related symptoms.

This study aims to provide objective evidence regarding the usefulness of digital occlusal analysis in the diagnosis and follow-up of bruxism and to evaluate the effectiveness of Botulinum Toxin-A treatment using both objective and subjective outcome measures.

Study Overview

• Status: Not yet recruiting
• Conditions: Bruxism
• Intervention / Treatment: Drug: Botulinum Toxin-A injection; Drug: Placebo (saline injection)

Detailed Description

Bruxism is a repetitive jaw-muscle activity characterized by clenching and/or grinding of the teeth and is associated with various oral and craniofacial consequences, including tooth wear, muscle pain, headaches, and temporomandibular disorders. Recent international consensus statements define bruxism as a motor behavior rather than a disease entity, emphasizing the need for multidimensional assessment approaches.

Current diagnostic methods primarily rely on self-reported symptoms and clinical findings. However, self-reports may be affected by recall bias and limited awareness, while clinical signs often reflect cumulative tissue changes rather than ongoing functional activity. Although electromyography and polysomnography can provide objective information regarding masticatory muscle activity, their routine clinical use is limited by cost, technical complexity, and accessibility.

Digital occlusal analysis systems have emerged as promising tools for the objective evaluation of occlusal force characteristics. These technologies allow quantitative assessment of bite force distribution, occlusal timing, and force balance, potentially providing indirect information about masticatory muscle function. Despite their increasing clinical use, the role of digital occlusal analysis systems in the diagnosis and longitudinal monitoring of bruxism remains insufficiently investigated.

Botulinum Toxin-A (BTX-A) has been increasingly used for the management of bruxism because of its ability to reduce masticatory muscle activity through inhibition of acetylcholine release at the neuromuscular junction. Previous studies have demonstrated reductions in bite force and symptom severity following BTX-A treatment. However, most available studies have focused on subjective outcomes or lacked placebo-controlled designs and objective functional measurements.

This study was designed to address these gaps by investigating whether digital occlusal analysis can serve as an objective tool for evaluating bruxism and monitoring therapeutic response. The findings may contribute to the development of more objective diagnostic and follow-up strategies for bruxism while providing additional evidence regarding the functional effects of Botulinum Toxin-A treatment.

• Study Type: Interventional
• Enrollment (Estimated): 36
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Yasemin Beliz Önder, DDS, PhD; Phone Number: +905532502064; Email: ybyilmaz@gmail.com

Study Locations

• Turkey (Türkiye)
  • Bilecik
    • Bilecik, Bilecik, Turkey (Türkiye), 11100
      • Department of Periodontology, Bilecik Seyh Edebali University Faculty of Dentistry
      • Contact: Beliz Yasemin Önder; Phone Number: 05532502064; Email: ybyilmaz@gmail.com
      • Contact: Muhammed Emin Kalender, DDS; Phone Number: +90 546 610 78 27; Email: ybyilmaz@gmail.com
      • Principal Investigator: Yasemin Beliz ÖNDER, DDS, PhD
      • Sub-Investigator: Muhammed Emin Kalender, DDS, PhD
      • Sub-Investigator: Taner TÜRKAY, DDS, PhD

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Adults aged 18 years and older
• Diagnosis of bruxism based on self-report and clinical assessment
• Systemically healthy individuals
• Angle Class I occlusion
• Ability and willingness to provide written informed consent and comply with study procedures

Exclusion Criteria:

• Presence of temporomandibular joint pathology
• Neuromuscular disorders
• Pregnancy or lactation
• Known allergy or hypersensitivity to Botulinum Toxin-A
• Use of medications that may affect muscle function
• Missing posterior teeth
• Ongoing orthodontic treatment
• Angle Class II or Class III malocclusion
• Previous Botulinum Toxin injection into the masseter muscles

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Botulinum Toxin-A Group; Participants assigned to this arm will receive bilateral Botulinum Toxin-A injections into the masseter muscles. A total dose of 25 IU will be administered to each masseter muscle using a standardized three-point injection protocol. Participants will undergo follow-up assessments at baseline, 2 weeks, 3 months, and 6 months after treatment.	Drug: Botulinum Toxin-A injection; Botulinum Toxin-A administered bilaterally into the masseter muscles at a total dose of 25 IU per muscle using a standardized three-point injection protocol.
Placebo Comparator: Placebo Group; Participants assigned to this arm will receive bilateral saline (0.9% sodium chloride) injections into the masseter muscles using the same anatomical injection sites and injection protocol as the experimental group. Participants will undergo follow-up assessments at baseline, 2 weeks, 3 months, and 6 months after treatment.	Drug: Placebo (saline injection); 0.9% sodium chloride solution administered bilaterally into the masseter muscles using the same anatomical sites and injection protocol as the experimental group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Maximum Bite Force Measured by the OccluSense Digital Occlusal Analysis System	Maximum bite force will be assessed using the OccluSense digital occlusal analysis system. Participants will be instructed to perform maximum intercuspation under standardized conditions. The OccluSense system will record the magnitude and distribution of occlusal forces during maximal clenching. Three consecutive measurements will be obtained at each assessment visit, and the mean value will be used for analysis. Changes in maximum bite force from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate treatment-related changes in masticatory muscle function and occlusal force generation.	Baseline, 2 Weeks, 3 Months, and 6 Months
Change in Right/Left Occlusal Force Balance Measured by the OccluSense Digital Occlusal Analysis System	Right/left occlusal force balance will be assessed using the OccluSense digital occlusal analysis system. The percentage distribution of occlusal forces between the right and left sides of the dental arch will be recorded during maximum intercuspation under standardized conditions. Three consecutive measurements will be obtained at each assessment visit, and the mean value will be used for analysis. Changes in right/left force balance from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate treatment-related changes in occlusal force distribution and masticatory muscle function.	Baseline, 2 Weeks, 3 Months, and 6 Months
Change in Anterior/Posterior Occlusal Force Distribution Measured by the OccluSense Digital Occlusal Analysis System	Anterior/posterior occlusal force distribution will be assessed using the OccluSense digital occlusal analysis system. The percentage distribution of occlusal forces between the anterior and posterior regions of the dental arch will be recorded during maximum intercuspation under standardized conditions. Three consecutive measurements will be obtained at each assessment visit, and the mean value will be used for analysis. Changes in anterior/posterior force distribution from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate treatment-related changes in occlusal loading patterns and masticatory muscle function.	Baseline, 2 Weeks, 3 Months, and 6 Months
Change in Occlusion Time Measured by the OccluSense Digital Occlusal Analysis System	Occlusion time will be assessed using the OccluSense digital occlusal analysis system. Occlusion time is defined as the elapsed time from the first tooth contact until maximum intercuspation is achieved during closure. Measurements will be performed under standardized conditions during maximum intercuspation. Three consecutive recordings will be obtained at each assessment visit, and the mean value will be used for analysis. Changes in occlusion time from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate treatment-related changes in occlusal contact dynamics and masticatory muscle function.	Baseline, 2 Weeks, 3 Months, and 6 Months
Change in Disocclusion Time Measured by the OccluSense Digital Occlusal Analysis System	Disocclusion time will be assessed using the OccluSense digital occlusal analysis system. Disocclusion time is defined as the elapsed time required for posterior teeth to separate during mandibular excursive movements following maximum intercuspation. Measurements will be performed under standardized conditions, and three consecutive recordings will be obtained at each assessment visit. The mean value of the recordings will be used for analysis. Changes in disocclusion time from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate treatment-related changes in occlusal function, excursive movement dynamics, and masticatory muscle activity.	Baseline, 2 Weeks, 3 Months, and 6 Months
Change in Center of Force (COF) Measured by the OccluSense Digital Occlusal Analysis System	Center of Force (COF) will be assessed using the OccluSense digital occlusal analysis system. The COF represents the overall location of the resultant occlusal force based on the distribution and magnitude of occlusal contacts across the dental arch during maximum intercuspation. Measurements will be performed under standardized conditions, and three consecutive recordings will be obtained at each assessment visit. The mean value of the recordings will be used for analysis. Changes in COF position and distribution from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate treatment-related changes in occlusal force distribution, functional occlusal balance, and masticatory muscle activity.	Baseline, 2 Weeks, 3 Months, and 6 Months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Pain Intensity Assessed by the Visual Analog Scale (VAS)	Pain intensity will be assessed using a 10-cm Visual Analog Scale (VAS), where 0 indicates no pain and 10 indicates the worst pain imaginable. Participants will be asked to rate the intensity of pain or discomfort associated with bruxism-related symptoms, including masticatory muscle pain and jaw discomfort. Changes in VAS pain scores from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate the effect of treatment on pain-related outcomes.	Baseline, 2 Weeks, 3 Months, and 6 Months
Change in Maximum Mouth Opening Measured in Millimeters (mm)	Maximum mouth opening will be assessed as the maximum interincisal distance measured in millimeters (mm) between the incisal edges of the maxillary and mandibular central incisors during unassisted maximum mouth opening. Measurements will be obtained using a millimeter ruler under standardized clinical conditions at each assessment visit. Standardized clinical photographs will also be taken to document the measurements. Changes in maximum mouth opening from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate treatment-related changes in mandibular function and jaw mobility.	Baseline, 2 Weeks, 3 Months, and 6 Months
Change in Masseter Muscle Tenderness Assessed by Clinical Examination	Masseter muscle tenderness will be assessed by standardized clinical examination using digital palpation of the bilateral masseter muscles. Participants will be asked to rate tenderness or discomfort elicited during palpation, and findings will be recorded at each assessment visit. Changes in masseter muscle tenderness from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate treatment-related changes in masticatory muscle pain and sensitivity associated with bruxism.	Baseline, 2 Weeks, 3 Months, and 6 Months
Change in Jaw Functional Limitation Assessed by the Jaw Functional Limitation Scale-8 (JFLS-8)	Jaw functional limitation will be assessed using the 8-item Jaw Functional Limitation Scale (JFLS-8), a validated patient-reported outcome measure that evaluates limitations in mastication, jaw mobility, and verbal and emotional expression related to jaw function. Participants will complete the questionnaire at each assessment visit, and total scores will be calculated according to the instrument guidelines. Changes in JFLS-8 scores from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate treatment-related changes in jaw function and functional impairment associated with bruxism. The Jaw Functional Limitation Scale-8 (JFLS-8) is a questionnaire designed to assess the degree of mandibular dysfunction during activities such as chewing tough food, chewing chicken, eating soft food requiring no chewing, opening wide enough to drink from a cup, swallowing, yawning, talking, and smiling.	Baseline, 2 Weeks, 3 Months, and 6 Months
Change in Bruxism-Related Morning Symptoms and Parafunctional Habits Assessed by Self-Report Questionnaire	Bruxism-related morning symptoms and parafunctional habits will be assessed using a self-report questionnaire administered at each assessment visit. The questionnaire will evaluate the presence and frequency of symptoms commonly associated with bruxism, including morning jaw fatigue, jaw muscle soreness, headache upon awakening, tooth clenching, and tooth grinding behaviors. Changes in self-reported morning symptoms and parafunctional habits from baseline to 2 weeks, 3 months, and 6 months after intervention will be compared between the Botulinum Toxin-A and placebo groups to evaluate treatment-related changes in bruxism-related symptom burden and oral parafunctional activity.	Baseline, 2 Weeks, 3 Months, and 6 Months

Collaborators and Investigators

• Sponsor: Bilecik Seyh Edebali Universitesi

Publications and helpful links

General Publications

• Manfredini D, Ahlberg J, Aarab G, Bender S, Bracci A, Cistulli PA, Conti PC, De Leeuw R, Durham J, Emodi-Perlman A, Ettlin D, Gallo LM, Haggman-Henrikson B, Hublin C, Kato T, Klasser G, Koutris M, Lavigne GJ, Paesani D, Peroz I, Svensson P, Wetselaar P, Lobbezoo F. Standardised Tool for the Assessment of Bruxism. J Oral Rehabil. 2024 Jan;51(1):29-58. doi: 10.1111/joor.13411. Epub 2023 Feb 10.
• Verhoeff MC, Lobbezoo F, Ahlberg J, Bender S, Bracci A, Colonna A, Dal Fabbro C, Durham J, Glaros AG, Haggman-Henrikson B, Kato T, Koutris M, Lavigne GJ, Nykanen L, Raphael KG, Svensson P, Wieckiewicz M, Manfredini D. Updating the Bruxism Definitions: Report of an International Consensus Meeting. J Oral Rehabil. 2025 Sep;52(9):1335-1342. doi: 10.1111/joor.13985. Epub 2025 May 1.
• da Silva Ramalho JA, Palma LF, Ramalho KM, Tedesco TK, Morimoto S. Effect of botulinum toxin A on pain, bite force, and satisfaction of patients with bruxism: A randomized single-blind clinical trial comparing two protocols. Saudi Dent J. 2023 Jan;35(1):53-60. doi: 10.1016/j.sdentj.2022.12.008. Epub 2022 Dec 24.
• Li K, Tan K, Yacovelli A, Bi WG. Effect of botulinum toxin type A on muscular temporomandibular disorder: A systematic review and meta-analysis of randomized controlled trials. J Oral Rehabil. 2024 May;51(5):886-897. doi: 10.1111/joor.13648. Epub 2023 Dec 27.

Study record dates

Study Major Dates

• Study Start (Estimated): July 20, 2026
• Primary Completion (Estimated): December 20, 2026
• Study Completion (Estimated): July 20, 2027

Study Registration Dates

• First Submitted: June 1, 2026
• First Submitted That Met QC Criteria: June 5, 2026
• First Posted (Actual): June 10, 2026

Study Record Updates

• Last Update Posted (Actual): June 10, 2026
• Last Update Submitted That Met QC Criteria: June 5, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Botulinum Toxin Type A; Bruxism; Masseter Muscle; Bite Force; Placebo-Controlled Trial; Digital Occlusal Analysis; Occlusal Force Distribution; Masticatory Muscle Activity
• Additional Relevant MeSH Terms: Stomatognathic Diseases; Tooth Diseases; Behavior; Habits; Bruxism; Amino Acids, Peptides, and Proteins; Proteins; Biological Factors; Hydrolases; Enzymes; Enzymes and Coenzymes; Inorganic Chemicals; Chlorine Compounds; Botulinum Toxins; Metalloendopeptidases; Endopeptidases; Peptide Hydrolases; Metalloproteases; Bacterial Proteins; Bacterial Toxins; Toxins, Biological; Sodium Compounds; Chlorides; Hydrochloric Acid; Botulinum Toxins, Type A; Sodium Chloride
• Other Study ID Numbers: BSEU-ONDER-002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: No plan to share individual participant data is currently in place. Participant confidentiality and privacy considerations limit public data sharing.

Drug and device information, study documents

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