Botulinum Toxin-A for Bruxism Using Digital Occlusal Analysis

Official title

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

Overview

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.

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.

Interventions

• 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.
• 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.

Primary outcome measures

• Change in Maximum Bite Force Measured by the OccluSense Digital Occlusal Analysis System [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 [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 [Time frame: Baseline, 2 Weeks, 3 Months, and 6 Months]
• Change in Occlusion Time Measured by the OccluSense Digital Occlusal Analysis System [Time frame: Baseline, 2 Weeks, 3 Months, and 6 Months]
• Change in Disocclusion Time Measured by the OccluSense Digital Occlusal Analysis System [Time frame: Baseline, 2 Weeks, 3 Months, and 6 Months]
• Change in Center of Force (COF) Measured by the OccluSense Digital Occlusal Analysis System [Time frame: Baseline, 2 Weeks, 3 Months, and 6 Months]

Secondary outcome measures (5)

• Change in Pain Intensity Assessed by the Visual Analog Scale (VAS) [Time frame: Baseline, 2 Weeks, 3 Months, and 6 Months]
• Change in Maximum Mouth Opening Measured in Millimeters (mm) [Time frame: Baseline, 2 Weeks, 3 Months, and 6 Months]
• Change in Masseter Muscle Tenderness Assessed by Clinical Examination [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) [Time frame: Baseline, 2 Weeks, 3 Months, and 6 Months]
• Change in Bruxism-Related Morning Symptoms and Parafunctional Habits Assessed by Self-Report Questionnaire [Time frame: Baseline, 2 Weeks, 3 Months, and 6 Months]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Turkey (Türkiye) · 1 center

• Department of Periodontology, Bilecik Seyh Edebali University Faculty of Dentistry — Bilecik

Publications

• 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. PMID 36817026
• 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. PMID 38151884
• 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. PMID 36597658
• 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. PMID 40312776

Identifiers

NCT: NCT07640035 · BSEU-ONDER-002

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗