Evaluation of the Effect of Muscle Activity on Subjective Tinnitus in Temporomandibular Disorders
Phase: NA
Conditions: Tinnitus, Subjective, Temporomandibular Disorder
Sponsor: Kutahya Health Sciences University

 
STUDY PROTOCOL (20.12.2021) 
 
 
Title of Study: 
 
Evaluation of the Effect of Muscle Activity on Subjective Tinnitus in Temporomandibular 
Disorders 
 
Title, name, area of expertise and place of duty of principal investigator: 
Berkan Altay, Department of Oral and Maxillofacial Surgery; Kütahya University of Health 
Sciences Faculty of Dentistry 
 
Title, names, fields of expertise and place of duty of all researchers who will be involved 
in the research: 
Vural Kavuncu, Physical Medicine and Rehabilitation; Kütahya University of Health Sciences 
Faculty of Medicine 
Berkan Altay, Department of Oral and Maxillofacial Surgery; Kütahya University of Health 
Sciences Faculty of Dentistry 
Berceste Güler, Department of Periodontology; Kütahya University of Health Sciences Faculty 
of Dentistry 
Selver Suna Başak, Department of Prosthodontics; Kütahya University of Health Sciences 
Faculty of Dentistry 
Mehmet Çağatay Ulucan, Department of Prosthodontics; Kütahya University of Health 
Sciences Faculty of Dentistry 
Merve Akdeniz Chickpeas; Physical Medicine and Rehabilitation; Kütahya University of 
Health Sciences Faculty of Medicine 
Elif Çoban, Department of Oral and Maxillofacial Surgery; Kütahya University of Health 
Sciences Faculty of Dentistry 
Where the research will be conducted:  
Kütahya University of Health Sciences Faculty of Dentistry 
PHASE OF THE RESEARCH 
AND 
TYPE 
PHASE 1 
☐ 
PHASE 2 
☐ 
PHASE 3 
☐ 
PHASE 4 
☐ 
observational drug study 
☐ 
Medical device clinical research 
☐ 
Performance evaluation studies with in 
vitro medical diagnostic devices 
☐ 
Non-drug clinical research 
☒ 
If other, specify: 
The planned date range of the research: 25.12.2021-15.11.2022 
 

The hypothesis of the research: 
µ = 1 hypothesis: Temporomandibular disorder accompanied by subjective tinnitus and 
treatment of bruxism with an occlusal splint; It has an effect on the decrease in the levels of 
tinnitus, bruxism and temporomandibular disorder. 
 
µ = 0 hypothesis: Temporomandibular disorder accompanied by subjective tinnitus and 
treatment of bruxism with occlusal splint; It has no effect on the decrease in the levels of 
tinnitus, bruxism and temporomandibular disorder. 
 
 
Introduction-Purpose Section: 
Temporomandibular disorders; is a general term describing disorders of the masticatory 
muscles, temporomandibular ligaments, and temporomandibular joint (TMJ). The most 
common symptoms of these disorders are pain in the preauricular region and masticatory 
muscles, limitation/irregularity in joint movements and sounds coming from the joint. 
Additional symptoms include; headache, tinnitus, dizziness, hearing loss, sleep disturbance, 
and chronic fatigue. Bruxism is one of the most common predisposing factors that cause 
temporomandibular disorders. 
 
Bruxism is a repetitive jaw-muscle activity that occurs with mandible movement characterized 
by clenching and/or grinding of the teeth. Bruxism can occur during the day or night while 
sleeping or awake. While clenching is more prominent in diurnal bruxism, grinding is seen in 
addition to clenching in nocturnal bruxism. Factors such as stress, occlusal irregularities, 
allergies, and sleep quality are discussed in its etiology. Treatment includes botulinum toxin 
injection and/or occlusal splint. 
 
Occlusal splints are one of the most common and first-choice treatment modalities in patients 
with TMD and bruxism, as they are a non-invasive and easily accessible treatment option. These 
splints are used to correct the static and dynamic effects of the stomatognathic system. With the 
occlusal splint, equal and balanced occlusal contact is achieved without permanently changing 
the resting position of the mandible and/or dental occlusion. It is usually in the form of a dental 
retainer or removable prosthesis made of hard acrylic. The most commonly used type of 
occlusal splint is the Michigan type bite splint. This splint is mostly used in the maxilla. The 
main purpose of this appliance is to separate the occlusion, put the condyle in a centric position, 
relax the chewing muscles and prevent further tooth wear due to parafunctional activity. The 
main feature of the Michigan type bite splint is that it can easily provide centric and canine-
protected occlusion. 
 
Tinnitus is defined as the perception of sounds in one's ears or inside the head without any 
acoustic stimulus. Sounds can be perceived in the ear or in the head. Microtrauma associated 
with repetitive activities, such as bruxism, is considered a risk factor for the onset and 
persistence of muscle pain and may be directly related to the symptom of tinnitus. Hyperactivity 
in the masticatory muscles as a result of bruxism may affect the tensor tympani muscle and the 
auditory system and trigger tinnitus. 1 Ramirez et al. reported that the tensor veli palatini muscle 

lost its function in patients with bruxism, and the position of the tympanic membrane and 
malleus could change due to its union with the tensor tympani muscle. 2 Therefore, they reported 
that velopharyngeal, neck and facial movements have an important role in the symptoms of 
otic-temporomandibular disorder. 2 In the study by Camparis et al., it was found that the 
frequency of tinnitus is high in patients with sleep bruxism and chronic myofascial pain; At the 
same time, it was reported that the number of painful areas on palpation in the chewing and 
cervical muscles and the absence of teeth were more common in the tinnitus group, and the 
tinnitus frequency was higher in patients with sleep bruxism. 3 In the study of Kuttila et al., it 
was reported that the pain in the chewing muscles in patients with tinnitus was higher than the 
control group. 4 Bernhardt et al. reported that tinnitus patients had more muscle and TMJ pain 
than the control group. 5 According to the positive correlation between bruxism and tinnitus; 
Since oral parafunctions trigger both conscious and unconscious jaw movements, it is thought 
that abnormal activity of the masticatory muscles and jaw joint may trigger a more intense 
tinnitus sensation. 
 
Electromyography (EMG is the most reliable method to record muscle function and activity 
with electrical potentials. It is a graphical recording of the electrical potentials of the muscles. 
In the EMG method, the tool is the electrode that provides the connection between the biological 
tissue and the recording system. There are 2 basic types of electrodes. These are superficial and 
needle electrodes. Surface electrodes are noninvasive. They do not cause infection. With this 
technique, only the activities of localized muscles close to the skin can be detected. Therefore, 
masseter or anterior temporal muscle activities are mostly examined. Patients do not want this 
application because the hair must be cut to detect the medial and posterior fibers of the temporal 
muscle. If the activity of the pterygoid muscle is detected anatomically difficult. Low 
reproducibility as a result of impedance inconsistency. EMG provides information about the 
functions of the stomatognatic system in TMD patients with minimal discomfort and a non-
invasive method. 6 Surface electromyography of the masticatory muscles allows an objective 
distinction between different TMD subgroups and does not support conventional clinical 
assessments. might help. 7 In the literature, there are studies evaluating temporomandibular 
disorders and bruxism with EMG, studies examining the correlation between masticatory 
muscles and subjective tinnitus with subjective and EMG, studies examining the treatment of 
temporomandibular disorders and bruxism with occlusal splint with EMG. However, subjective 
tinnitus seen with temporomandibular disorders/bruxism; There are no studies investigating the 
treatment and management of these diseases. It is presented in discussion. At the same time, 
the anatomical differences discussed in the etiology of subjective tinnitus associated with 
temporomandibular disorders/bruxism, and the question of common phylogenetic origin still 
remain unresolved. In our study, only TMD and TMD+bruxism groups, etiological factor 
questions and treatment of these diseases, changes in masticatory muscles and the management 
of subjective tinnitus will be investigated. 
 
In this study, we also; We aimed to treat patients with temporomandibular disorder 
accompanied by tinnitus with the use of occlusal splint, which is minimally invasive and the 
most preferred method. At the same time, we aimed to compare the data between the use of 
superficial EMG and the electrical activity of the masseter muscle, which is the main chewing 

muscle, and temporomandibular disorder, bruxzyme, subjective tinnitus, and to elucidate the 
etiology of subjective tinnitus, which is the subject of discussion in the literature. The use of an 
occlusal splint is one of the most effective methods in the management of temporomandibular 
joint disorders and in reducing symptoms such as joint/muscle pain and limitation in mouth 
opening. With this treatment method, simultaneous treatment of subjective tinnitus seen with 
the temporomandibular joint is aimed. 
 
Material-Methods Section: 
 
The study will be conducted with patients who routinely apply to Kütahya Health Sciences 
University Faculty of Dentistry. 70 patients with temporomandibular disease accompanied by 
tinnitus and bruxism will be included in the study. Demographic data such as age, gender, and 
systemic disease, drug and trauma history data will be collected. 
 
TMD findings of the patients will be classified according to Wilkes classification. The Wilkes 
classification is as follows: 
1. Stage 1 (early period): No pain or limitation of jaw movements, only reciprocal click during 
or after chewing. Mild anterior disc displacement in radiological evaluation. 
2. Stage 2 (early/intermediate): Mild to moderate pain with reciprocal clicking and periodic 
locking. Change in disc position. 
3. Stage 3 (intermediate): Joint tenderness with frequent pain. Ongoing crash. On the 
radiological image, changes in disc position and deformation with adhesions. 
4. Stage 4 (intermediate/late): Chronic pain that gets worse from time to time and limitation in 
jaw movements. Change in the shape and position of the disc and the shape of the condyle. 
Multiple adhesions with hard tissue changes. 
5. Stage 5 (late stage): pain that occurs from time to time with crepitation. 
 
Bruxism data (time of onset, whether it is felt during the day/night, fatigue, difficulty in opening 
the mouth in the morning, stressful period) are questioned and examination findings (disc 
displacement, masseter hypertrophy on inspection, linea alba, attrition of teeth, fractures in 
restorations and teeth, muscle and joint pain) , facial asymmetry, mouth opening) will be 
recorded. The characteristics of tinnitus (objective/subjective, duration, in which ear, increasing 
and decreasing factors, type) and hearing loss, vertigo will be questioned. 
 
Patients will be divided into two groups. Group I will consist of Wilkes Stage 1-2 patients with 
temporomandibular intra-articular disorder. Group II will consist of patients with both Wilkes 
Stage 1-2 temporomandibular intra-articular disorder and bruxism. 
 
In order to measure the muscle strength of the patients before the treatment, in order to reach 
the chewing muscles easily and to minimize the patient's discomfort, EMG containing right-
left M. Masseters will be taken. The analog EMG signal will be amplified using a differential 
amplifier with a high common-mode rejection ratio (bandwidth 5 KHz, peak-to-peak input 
range 200 μV ). The average of the signals is over 500 ms. (Micromed, Italy) 
Superficial EMG will be taken following the following protocol: 

 
● To reduce skin impedance, the skin will be cleaned before electrode placement and 
recordings will be made after 5-6 minutes. 
● Superficial electrodes will be placed on the right and left masseter muscles, with the upper 
pole of the electrode parallel to the intersection between the tragus-labial commissura and 
the exocantion-gonion lines. The grounding electrode will be placed in the forehead area. 
● For all tests, patients will be seated with their head unsupported and asked to maintain a 
natural upright position. 
● To avoid any effects of fatigue, a rest period of at least 3 minutes will be allowed between 
tests. The average EMG potential for each of the muscles will be set to 100%. 
● To standardize EMG potentials, two 10 mm thick cotton rolls will be placed on each 
subject's mandibular first and second molars, and maximum voluntary clamping of 5 
seconds will be recorded. For 5 seconds, the patient will be encouraged to maintain the 
same level of contraction. EMG data analysis for all tests, the best 3-s period (the one with 
the most stable signal) will be automatically selected by the software and used for all 
subsequent analysis. 
● Electromyographic activity will then be recorded with a maximum voluntary squeeze at 
the intercuspal position; The patient will be invited to squeeze as hard as possible and 
maintain the same level of contraction for 5 seconds. Electromyographic activity will also 
be taken again while the patient is at rest. 
● For each subject, the EMG potentials of the analyzed muscles recorded during the 
maximum voluntary clamping tests will be expressed as a percentage of the average 
potential recorded during the standardization test (maximum voluntary clamping on cotton 
rolls). 
o (μV/μV×100). 
● To assess muscle symmetry, the EMG waves of the masseter muscles will then be 
compared by calculating a percent overlap coefficient (POC, %). POC is an index of the 
symmetrical distribution of muscle activity determined by occlusion. The index ranges 
from 0% to 100%: a POC of 100% will be achieved when two paired muscles contract 
with perfect symmetry. 
 
 
Tinnitus and bruxism will be evaluated by the patient with the VAS score. Tinnitus level will 
additionally be measured with the Tinnitus Handicap Inventory. Then, an occlusal splint will 
be prepared for the patients. occlusal splints; will be done with canine-protected occlusion and 
necessary occlusal arrangements will be made before the plates are delivered to the patients. 
Splints will be manufactured from hard acrylic and personalized measurements will be taken 
and the model will be prepared and made. It will be recommended to use them for 24 weeks. 
Postoperative EMG, Tinnitus Handicap Inventory and VAS scores will be re-evaluated after 
the use of the occlusal splint. 
 
In the light of the data obtained; Age, gender, disease findings, preoperative and postoperative 
Tinnitus Handicap Inventory, VAS scores, masseter and temporal muscle strength in EMG will 
be compared and evaluated. 

 
Inclusion criteria: 
Patients older than 18 years 
Patients with chronic subjective tinnitus 
Patients with Wilkes Stage 1-2 
Patients with bruxism 
 
Exclusion criteria: 
Patients with Wilkes Stage 3-4-5 
Patients with tinnitus due to audiological, neurological, metabolic or pathological reasons 
Patients with objective tinnutus 
Patients with normal tinnitus 
Mentally retarded patients 
Hearing loss, use of ototoxic drugs 
Those with ear diseases such as acute ostitis media, perforated tympanic membrane 
Those with Meniere's disease 
Patients with middle ear pathology 
Those with intracranial pathology 
Those with traumatic cervical spine injury 
Patients with severe depression diagnosed by a psychologist 
Patients who have received TMB treatment in the last two months 
 
Sample Selection: Significance in the G Power analysis program with reference to a previously 
presented study. When the effect size was taken as 0.08 for the value, it was planned to recruit 
70 patients for α= 0.05 and 80% power. 
 
Statistical method to be used: All analyzes will be done with SPSS software. In-group 
temporal evaluations in test and control groups will be evaluated using Pairedsample –T or 
Wilcoxon test according to normal distribution values. For comparisons between groups, 
according to the normal distribution of the data, Student-t test will be used for parametric 
within-group evaluations and Mann Withney U test will be used for non-parametrics. The 
normal distribution of the data will be evaluated with the Kolmogorov-Smirnov test. The 
significance value will be taken as 0.05. Relationships between variables will be evaluated with 
Logistic Regression Analysis or Multivariate Regression Analysis. 
 

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TR 
KÜTAHYA HEALTH SCIENCES UNIVERSITY 
TO THE CHAIRMAN OF THE CLINICAL RESEARCH ETHICS COMMITTEE 
 
 
 
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