An Early Phase 1 interventional study of Botulinum Toxin-A injection and Placebo (saline injection) in Bruxism, sponsored by Bilecik Seyh Edebali Universitesi. Not yet recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 64 Years. Per ClinicalTrials.gov, last updated 2026-10-02.
Sponsored by Bilecik Seyh Edebali Universitesi · Early Phase 1, Interventional, and Treatment
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.
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.
151 studies on the registry are indexed under Bruxism; 39 are open to participants now.
This study's planned enrollment of 36 is close to the median of 39 across 94 interventional studies indexed under Bruxism.
Browse Bruxism studies →Bilecik Seyh Edebali Universitesi is the lead sponsor of 62 studies on the registry; 27 are open to participants now.
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Exclusion Criteria:
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Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
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)
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.
0.9% sodium chloride solution administered bilaterally into the masseter muscles using the same anatomical sites and injection protocol as the experimental group.
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: Baseline, 2 Weeks, 3 Months, and 6 Months
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: Baseline, 2 Weeks, 3 Months, and 6 Months
Plan to share: No — No plan to share individual participant data is currently in place. Participant confidentiality and privacy considerations limit public data sharing.
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Studies of the drug tested here: Botulinum toxin type A
Bilecik Seyh Edebali Universitesi