Training of the Lateral Pterygoid Muscle in the Treatment of Anterior Temporomandibular Joint Disc Displacement With Reduction With Pain
Phase: NA
Conditions: Facial Pain, Temporomandibular Disorder, Temporomandibular Joint Disorders, Temporomandibular; Functional Disturbance
Sponsor: University Medicine Greifswald

1 
 
Training of the lateral pterygoid muscle in the treatment of anterior 
temporomandibular joint disc displacement with reduction with pain 
 
Physical exercises for temporomandibular disorders 
 
Unique Protocol ID: 0016032021 
Document Date: March 16, 2021 
List of abbreviations 
 
 
DC/TMD 
Diagnostic Criteria for Temporomandibular Disorder 
DDWR 
Disc displacement with reduction 
JFLS-8  
Jaw Functional Limitation Scale 
mm 
 
Millimeter 
NRS  
Numeric rating scale 
TMD  
Temporomandibular Disorder 
TMJ  
Temporomandibular Joint 
 
 
 
 
 
Abstract 
Temporomandibular Disorders are a common clinical picture that appear in particular 
in people between the age of 20 and 40 years. About 33% of the total population 
shows symptoms and signs of TMD. Among the temporomandibular joint disorders 
anterior disc displacement appear to be the most common. In case of limitations of 
jaw movements and or pain conservative methods including combinations of 
behavior change, physiotherapy, stabilization appliance therapy and medication are 
most popular. The benefit of a self-treatment program to strengthen the lateral 
pterygoid muscle and to learn a properly executed lower jaw sideways movement to 
achieve pain reduction is up to now not well investigated. The aim of this study is to 
examine the effectiveness of muscle training for the treatment of patients with 
anterior disc displacement with reduction (DDWR). 60 patients with DDWR and pain 
(≥18 years) will be randomly allocated to two groups: 1. Physical exercises, 2. 
Stabilization appliance therapy. All patients receive a functional examination 
according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) at 
baseline. 
The training in group 1 includes eccentric and concentric counter-movements of the 
lower jaw muscle to strengthen and restore a physiological lateral movement of the 
mandible. The muscle exercises should be performed once a day with 5-6 repetitions 
per side. The treatment with an equilibration appliance in the lower jaw serves as a 
comparison group. Patients are instructed to wear the appliance while sleeping. The 
wearing rhythm is described as intermittent. (three nights - wearing the appliance, one 
night – not wearing the appliance). The primary target variable is the occurrence of 
pain in the head and joint area before and during therapy. The variable is measured 
using a numeric rating scale (NRS; 0-10) during the baseline examination and control 
check-ups after 2, 4 and 6 months. 

2 
 
 
 
Scientific background 
 
The literature describes the cause of a temporomandibular disorder (TMD) as a 
multifactorial event [20]. It can be influenced by anatomical, neuromuscular, traumatic 
or psychosocial factors [3]. Disturbances often occur in the condyle-disc complex of 
the temporomandibular joint [4]. The relationship between the articular disc and the 
condyle head is pathologically altered. The Diagnostic Criteria for Temporomandibular 
disorders (DC / TMD) describe the displacement of the disc in 4 different forms: disc 
displacement with reduction; disc displacement with reduction and intermittent locking; 
disc displacement without reduction with limited opening and disc displacement without 
reduction without limited opening [17]. TMDs are a common clinical picture that 
appears in particular in people between the age of 20 and 40 years. About 33% of the 
total population show signs and symptoms of TMD [16], [21]. 
Studies prove that the displacement of the disc with reduction is the most common 
disorder among temporomandibular joint disorders [6], [19]. According to the DC / 
TMD, this clinical picture shows intracapsular and biomechanical alterations. If the 
mouth is closed, the articular disc is often located in front of the mandibular condyle; if 
the mouth is opened, the disc moves back to its original position on the condyle. 
Anterior disc displacement appears to be the most common, although a medial or 
lateral displacement is also possible. During the disc repositioning clicking, popping or 
snapping noises are usually recorded [17]. Temporomandibular joint disorders such as 
disc displacement, can also cause pain [7], [8]. Overstretching of the posterior ligament 
and a compression of the bilaminar zone mandibular movements can be pain-related. 
Therefore, clicking, popping or snapping noises in the area of the temporomandibular 
joint (TMJ) correlate with pain in the surrounding tissue. Those complaints intensify 
when opening the mouth or chewing food [2], [15].  
The treatment of TMD should be oriented on evidence-based procedures that are easy 
to implement in practice and have a long-term positive effect on the patient's symptoms 
[22]. 
Conservative 
methods 
including 
combinations 
of 
behavior 
change, 
physiotherapy, splint-therapy and medication are most popular [10], [13], [14]. The 
physiotherapeutic treatment should pursue different strategies, including manual 
therapy methods (e.g. mobilization and stretching of the temporomandibular joint and 
/ or the neck area) and the demonstration of exercises in everyday life (e.g. self-
mobilization and stretching of the masticatory muscles and / or cervical spine) and in 
addition educating the patient (e.g. about the perception of parafunctions or relaxation 
techniques) [11], [22]. Conservative attempts for patients with TMD should be the first 
choice. However, there is still no clear data situation and the data pool of randomized 
clinical studies on this topic needs to be improved. So far studies demonstrate a 
positive effect of the tested therapy forms. But the individual studies differ greatly in 
terms of the patient pool, diagnosis, treatment modalities and the result [18]. 
Furthermore, a precisely described procedure is missing in some papers. Therefore, 
an exact reproducibility for practitioners is not executable. More research is needed 
into the benefits of various non-invasive treatments for TMD.  
The primary goal of this study is to decrease the ambiguity in this scientific field. In the 
past various manual and physiotherapeutic exercise methods have already been 
tested [9], [12]. 

3 
 
This study is also intended to examine the effectiveness of muscle training for the 
treatment of patients with anterior disc displacement with reduction. The exercises 
are primarily supposed to train the lateral pterygoid muscle. The treatment with an 
stabilization appliance in the lower jaw serves as a comparison group.  
 
 
Hypothesis 
 
In this study, patients with anterior disc displacement with reduction are treated with 
muscle training of the lateral pterygoid muscle. The treatment with an stabilization 
appliance in the lower jaw serves as a comparison group. 
 
1. By strengthening the lateral pterygoid muscle and learning a properly executed 
lower jaw sideways movement, pain reduction is achieved in patients with an anterior 
disc displacement with reduction. 
 
2. By strengthening the lateral pterygoid muscle and learning a properly executed 
lower jaw sideways movement, the cracking phenomenon during jaw opening or jaw 
closing movements in patients with an anterior disc displacement with reduction is 
reduced. 
Study design 
 
 
Prospective, randomized study with control group, stratified by gender. 
The type of therapy is assigned randomly. 
The study is unblinded for the doctor and patient. 
It is not possible to blind the practitioner because he is familiar with the forms of 
treatment. Since the practitioner and examiner are one and the same person in the 
practice, blinding is not possible here either. 
It is also not possible to blind the patient, as they are able to research the form of 
therapy. During the last examination, the participants of the study are asked whether 
they have researched the respective form of treatment. 
Target criteria 
Primary outcome variable 
 
The primary outcome variable is defined as the change of orofacial pain in the head and 
joint area after initiating the therapy measured by numeric rating scale (NRS; 0-10, 0: no 
pain, 10: worst imaginable pain) at the time of the follow-up appointments. 
 
Secondary outcome variables 
 
The following parameters are recorded as secondary target variables: 
- 
Change in number of clicking noises in the TMJ during jaw opening or jaw 
closing movements 
- 
Change in force degrees for lateral movement of the mandible according to 
Janda (modified scale from 4- to 5) 

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- 
Change in interincisal distance during maximum unassisted opening (in mm) 
 
Sample size estimation 
Determine the required sample size based on the numerical pain scale 0-10 for the 
primary target variable. Norms are pain scores of 3-5 (myofascial pain) in patients 
with craniomandibular dysfunction (CMD). To determine a mean difference of 2 level 
(standard deviation of 2 between the two treatment groups, they must each comprise 
24 patients. 
Test method: Wilcoxon-Mann-Whitney test with a two-sided α = 0.05, a power = 0.90 
assuming the family of logistic distributions (G * Power, version 3.1.) The net sample 
consists of 48 persons. Assuming a drop out 6 patients per group, a total sample of 
60 persons must be calculated. 
 
Methods of data collection 
 
The data is collected electronically and saved in the patient file. The required values 
for each patient were taken from the computer system of Dr. med. dent. Falk 
Pfanne’s dental practice. 
 
The patient fills in a symptom-related questionnaire before the initial examination 
starts. The questionnaire is based on the current requirements of the DC / TMD. 
Demographic data as well as questions about general pain, headaches, jaw noises 
or locking are answered. In addition, each patient completes a questionnaire on the 
grading of chronic pain (Version 2.0), the Jaw Functional Limitation Scale (JFLS-8) 
and the Oral Behavior Checklist. 
A functional examination is created during the baseline check-up. It is used to 
capture masticatory muscle and temporomandibular joint complaints based on a 
detailed anamnesis and subsequent clinical examination via palpation and inspection 
of the orofacial area. A standardized examination procedure adapted to the DC / 
TMD is used for this procedure. 
During the screening examinations (after 2, 4 and 6 months), the functional status as 
well as the primary (pain when opening or closing the mouth) and secondary 
(occurrence of the cracking phenomenon when opening or closing the mouth, Janda 
degrees of strength for laterotrusion movement, interincisal opening) target variables 
will be collected. 
Patient characteristics 
Treatment groups 
 
Treatment group 1: patients with anterior disc displacement with reduction 
Therapy: Static stretching and isometric contraction exercises of the lateral pterygoid 
muscle are used to strengthen and restore a physiological lateral movement of the 
mandible. The training is supervised in the dental practice and continued with self-

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exercises at home. The therapy is accompanied by an exercise movie on DVD 
produced by Dr.med.dent Falk Pfanne.  
 
Treatment group 2: patients with anterior disc displacement with reduction. 
Therapy: Stabilization appliance for the lower jaw 
 
Group size: 30 patients per group (60 patients in total) 
 
Description of the recruitment: The patients will be recruited in the dental practice 
 
Inclusion Criteria 
- 
Orofacial pain in the joint or muscles, degree NRS≥3 
- 
Clicking phenomenon during TMJ opening or closing movement 
- 
Deviation movement during opening of the lower jaw 
- 
Age: ≥ 18 years 
- 
Legal competence and presence of the signed declaration of consent 
Exclusion Criteria 
- 
Age <18 years 
- 
Drug abuse 
- 
Depression 
- 
Polyarthritis 
Test procedure 
Examiners 
 
 
All examinations and determinations of the individual measurement data are carried 
out by Dr. med. dent. Falk Pfanne, in his dental practice in Steina. 
The exercise instructions are supervised by Christin Olbort in the dental practice in 
Steina. 
 
Baseline examination 
 
For the baseline examination the patient's anamnesis is recorded and the dental 
status is ascertained. 
A panoramic radiograph must be available prior to the treatment in order to assess 
dental health and ensure the success of the treatment and it must not be older than 6 
months. Such an X-ray can be realized by the volunteer’s general dentist or the 
specialized dental practice in Steina. 
The functional examination is based on the standardized DC / TMD. 
Also, the inclusion and exclusion criteria for the planned form of therapy are checked. 
The assessment of the degrees of strength according to Janda during the lateral 
movement of the mandible requires a pain-free and coordinated sequence of 
movements. Subjects who experience unilateral or bilateral pain during this lower jaw 
movement cannot be included in the study. 
The assessment of patients, who are assigned to the muscle training group and who 
are diagnosed with a pain-free, but uncoordinated movement pattern, is based on the 

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Groot Landeweer coordination scale (I-III). The subjects who only achieve Grade II or 
III must first perform exercises to improve coordination during laterotrusion (exercises 
with a spatula). The development of the coordinative ability is reassessed through 
weekly checks. By achieving level I (according to Groot Landeweer), the strength 
level (according to Janda) for the lateral movement of the lower jaw can be 
determined. Instructions in muscle training can be given.  
These examination procedures are part of the routine examination in the “TMD 
Competence Center Westlausitz” for patients with temporomandibular disorders. 
 
Coordination according to Groot Landeweer [1]: 
 
I 
Coordinated execution of the movement 
II 
Execution of the movement only by using facial muscles and / or masticatory muscles 
III Inability to perform the movement 
 
Modified scale of the degrees of force according to Janda for laterotrusion [5]: 
 
4- Full movement against a slight resistance 
4 
Full movement against moderate resistance 
5- Full movement against clear resistance 
5 
Full movement against strong resistance / maximum strength  
 
Randomization 
The randomized grouping into blocks at a ratio of 1: 1 takes place generated random 
numbers by Excel. The assignment is stratified according to gender because gender 
is a strong predictor of temporomandibular dysfunctions. 
 
Preliminary exercise 
 
Coordination training for lateral movement of the mandible (spatula exercise): 
1. A wooden spatula is loosely placed between the teeth of the upper and lower 
jaw; the head must be aligned with the body axis; the exercise should be 
performed in front of a mirror. 
2. The lower jaw moves to the left and back to the center with little contact to the 
spatula  
3. The lower jaw moves to the right and back to the center under contact with the 
spatula 
 
Muscle Training 
Treatment effects are considered to be a result of proprioceptive neuro- muscular 
facilitation, increased awareness, stretching, and reciprocal muscle inhibition. 
Exercises have also been proposed to produce hypoalgesia by activation of the 
endogenous opioid system. 
 
Instructions for muscle training: 

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The training includes eccentric and concentric counter-movements of the lateral 
pterygoid muscle to strengthen and restore a physiological lateral movement of the 
mandible. The demonstration of the exercises takes place in the dental practice in 
Steina. Additionally, patients receive an exercise movie on DVD for self-instruction. It 
has been developed in the “CMD Westlausitz competence center”. The muscle 
exercises should be performed once a day with 5-6 repetitions per side. 
 
Training of the left lateral pterygoid muscle: 
1. The left palm is placed on the left temple region 
2. Right hand forms a fist and is placed on the tip of the right chin 
3. Both arms are aligned parallel to the surface of the floor 
4. The lower jaw is moved to the right against a moderate resistance of the fist   
= concentric muscle work 
5. With measured force of the fist, the lower jaw is brought back to the center     
= eccentric muscle work 
(Right lateral pterygoid muscle training with opposite hands.) 
Stabilization appliance therapy 
 
Upper and lower jaw impressions are registered by using an intraoral scanner. The 
arbitrary hinge axis position is determined using a face bow. 
The stabilization appliance with anterior canine guidance is manufactured in the 
Lexmann laboratory in Dresden. 
 
Integration: 
The stabilization appliance is incorporated by the dentist and the static and dynamic 
occlusion is checked. A tension-free fit of the appliance on the lower jaw is 
necessary. Additionally, equal contacts in the side teeth area and incisors guidance 
in the case of mandibular protrusion are checked visually and by using occlusion foil. 
During mandibular lateral movement only the canine guidance takes place and is 
also registered optically and by using occlusion foil.Interference contacts should be 
adjusted. 
The patient is instructed to wear the stabilization appliance while sleeping. The 
wearing rhythm is described as intermittent. (three nights - wearing the appliance, 
one night – not wearing the appliance). 
 
Control appointment for stabilization appliance group (1 week after integration) 
 
The first inspection takes place one week after the integration. The surface contacts 
in the side teeth area as well as the incisor and canine guidance are checked again. 
 
 
First control appointment (2 months after start of therapy) 
 
Two months after starting the therapy, an examination is carried out with a renewed 
assessment of the functional status. The primary (pain when opening or closing 
movements of the mouth) and secondary (occurrence of the cracking phenomenon 
when opening or closing movements, Janda degrees of strength in lateral movement 
of the mandible, interincisal opening distance) target variables are recorded. 
 

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Second control appointment (4 months after start of therapy) 
 
A second check is carried out 4 months after starting the therapy. The functional 
findings as well as the primary (pain when opening or closing the mouth movement) 
and secondary (occurrence of the cracking phenomenon when opening or closing the 
mouth movement, Janda strength levels for lateral movement of the mandible, 
interincisal opening distance) target variables are recorded. 
 
Third control appointment (6 months after the start of therapy) 
 
The last examination takes place 6 months after starting the therapy. The functional 
status as well as the primary (pain when opening or closing the mouth movement) 
and secondary (occurrence of the cracking phenomenon when opening or closing the 
mouth movement, Janda strength levels for lateral movement of the mandible, 
interincisal opening distance) target variables are recorded. 
 
Patient Safety 
 
Adverse events are recorded and the connection (certain, likely, unlikely) assessed. 
Serious or unexpected side effects are recorded on a separate form. 
 
Risks of the treatment execution  
 
There are no additional risks for the patients because the treatment methods of the 
study are based on routine clinical procedures. 
During the muscle training, the volunteers may occasionally experience an increase 
in pain (similar to muscle soreness) and headache or dizziness may occur. However, 
these side effects should disappear after the first week and regular exercising. 
In addition, the untrained muscles can be overloaded in the beginning. 
The basic risks of stabilization appliance therapy include allergic reactions to the 
material or incompatibilities in the oral cavity. 
Temporary side effects can include: dry mouth or increased salivation, changes in 
occlusion, feeling of tension / pain in teeth, oral mucosa or tongue, gagging or bad 
taste. Loss of tooth crowns, fillings or other dentures can only occur in rare cases. 
When wearing an stabilization appliance over a longer period of time (months to 
years), permanent changes in the teeth can be established in some cases, such as 
tooth migration, opening of interdental spaces, loss of teeth with periodontitis or 
missing molar contacts. 
In their entirety, risks and side-effects of these two treatment methods could be deem 
insignificant. 
Termination Criteria 
 
Adverse events can lead to premature termination of treatment. The following 
reasons could be possible: 
 
- Intolerance or allergic reactions 

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- Pain on teeth, muscles or jaw joints that cannot be controlled 
- Loosening of teeth 
- Changes in tooth position or occlusion that cannot be tolerated 
- Other physical or mental illnesses 
 
A study termination must be documented in the patient’s file by stating the 
corresponding reasons. A final examination of the volunteer is carried out. 
Patient safety must not be compromised. All safety and health examinations and 
treatments must be continued.  
The justification for an early termination of the study is only necessary under the 
points given above. 
Ethical and Regulatory Aspects 
 
This study is carried out with special attention to the content of the following laws and 
guidelines: 
 
• Declaration of Helsinki in its current version (Fortaleza, 2013) 
• Medizinproduktegesetz – MPG 
• Medizinprodukte-Betreiberverordnung – MPBetreibV  
• Landesdatenschutzgesetz – DSG M-V 
• Datenschutzgrundverordnung – EU-DSGVO  
 
Independent ethics committee 
 
The investigation will begin after consultation and approval by the responsible ethics 
committees and only if there are no ethical concerns. The head of this study (Prof. 
Dr. Olaf Bernhardt) is responsible for submitting applications to the ethics committee 
of the University Medical Center Greifswald. The application to the ethics committee 
of the Free State of Saxony is submitted by Christin Olbort and Dr. med. dent. Falk 
Pfanne. 
 
Patient information and consent 
 
Participation in this study is only possible by a written consent. After Dr. med. dent. 
Pfanne or Christin Olbort have advised the patients, both orally and in writing, about 
the nature, meaning and scope of the study in an understandable manner, they will 
provide sufficient time to make a decision. By signing the consent, the volunteers 
declare their agreement with the recording of data required for the study. 
The patient can withdraw his consent at any time, without giving any reason and 
experiencing any disadvantages.  
The patient receives an original copy of the written patient information and consent in 
written or digital form. A second original is kept safe in the “CMD Competence Center 
Westlausitz”. 
 

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Insurance  
 
The study describes approved clinical forms of therapy that have successfully passed 
the conformity assessment procedure and are CE marked. 
No additional invasive or stressful examinations are performed on the patient. The 
course of this study is based on clinical routine. Therefore, the patient is not exposed 
to any study-related risks. 
 
The treatment process and the check-up examinations are based on the clinical 
routine and the volunteer does not have to spend extra time due to the study. 
Therefore, it is not necessary to propose an additional insurance. 
 
Data protection 
 
The provisions of the data protection laws (in particular DSG MV and EU-DSGVO) 
are observed. All test materials and data are adequately pseudo-anonymized in 
accordance with the privacy policy. An assignment of the personal data to the study 
data may only be carried out by employees of the dental surgery of Dr. med. dent. 
Falk Pfanne in Steina. 
 
Statistical analysis plan  
Number of cases 
 
The total number of cases in the study was 60 people. 30 patients are assigned to 
the muscle training group and 30 patients are included in the comparison group with 
an equilibration splint. 
In addition, the study groups are differentiated according to the categorical factor of 
gender. 
 
Statistical analysis  
 
The evaluation of the target variables is carried out using descriptive and inductive 
statistics. 
In the descriptive statistical representation, the usual characteristic values such as 
frequency, mean values, standard deviation and range of values (minima, maxima) 
are used. 
Possible differences in the study groups are analyzed using parametric (double t-test) 
and non-parametric (Mann-Whitney U-test) methods. The Chi²- test is used to 
analyze possible relationships between the nominally scaled values (e.g. gender). 
The interpretation is based on a 95% confidence interval. The hypothesis testing 
procedure is based on an error probability of 5% [p = 0.05], which is often used in 
studies. 
 

11 
 
The evaluation of the blinded data is carried out by Christin Olbort. 
Data management 
Data collection 
 
The data for each patient are taken from the electronic patient file of Dr. med. dent. 
Falk Pfanne in Steina. This includes the questionnaire consisting of the baseline 
exmaination, x-rays, functional status, as well as the primary (pain when opening or 
closing the mouth) and secondary (occurrence of the cracking phenomenon when 
opening or closing the mouth, Janda degrees of strength in laterostrusion movement, 
interincisal opening distance) target variables. 
 
The forms are filled out, dated and signed by the test subjects or persons who are 
authorized to document them (dental practice employees). 
 
Data processing 
 
The data entry in the electronic patient file is carried out by the examiner 
Dr.med.dent. Falk Pfanne or his employees. All questionnaires and findings sheets 
that have been filled out by hand are scanned and also saved in the electronic file of 
each volunteer. 
 
The use of the data takes place in accordance with legal regulations and requires a 
voluntarily submitted and signed declaration of consent by the test persons before 
participating in the clinical study. 
The collected data may be passed on to Christin Olbort and the study director in 
pseudo-anonymized form for the purpose of scientific evaluation. 
Pseudo-anonymization is the replacement of the name and other identification 
features with a label in order to exclude the identification of the person concerned or 
to make it much more difficult (according to BDSG Section 3, Paragraph 6a). 
In comparison, anonymization means changing personal data in such a way that the 
individual information about personal and factual circumstances can no longer be 
assigned to a specific or identifiable natural person, or only with a disproportionately 
large amount of time, cost and labor (according to BDSG §3 Para. 6). 
The study participants declare their consent for the scientific publication of the 
research results in compliance with the data protection regulations (a conclusion to 
individual persons is excluded). 
Participation in the clinical study can be terminated at any time by the volunteer or 
the study director, even without giving reasons. When withdrawing their consent to 
participate in the study, participants have the right to request the deletion of all 
personal data stored up to that point. It is not possible to delete data that has already 
been analyzed. 
All data will be retained for at least ten years after the study is completed or 
discontinued. Thereafter, personal data will be deleted, unless there are statutory 
retention periods to the contrary. 
 
 

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References 
 
1.  
Bumann, A., Groot Landeweer, G.: Manuelle Untersuchungstechniken zur 
Manuellen Untersuchungstechniken zur Differenzierung von 
Funktionsstörungen im Kausystem. In Hahn, W.: Funktionslehre: aktueller 
Stand und praxisgerechte Umsetzung. Hanser, München, 1993 
2.  
Eberhard D (2002) The efficacy of anterior repositioning splint therapy studied 
by magnetic resonance imaging. The European Journal of Orthodontics 
24:343–352. doi: 10.1093/ejo/24.4.343 
3.  
Egermark I, Magnusson T, Carlsson GE (2003) A 20-year follow-up of signs 
and symptoms of temporomandibular disorders and malocclusions in subjects 
with and without orthodontic treatment in childhood. Angle Orthod 73:109–115. 
doi: 10.1043/0003-3219(2003)73<109:AYFOSA>2.0.CO;2 
4.  
El-Asfahani I, Kortam S (2020) Effect of CAD/CAM versus conventional 
anterior repositioning splints on the management of temporomandibular joint 
disc displacement with reduction: A randomized controlled clinical trial. 
Egyptian Dental Journal 66:571–585. doi: 10.21608/edj.2020.79131 
5.  
Janda V (2013) Muscle Function Testing. Butterworth-Heinemann 
6.  
Kalaykova SI, Lobbezoo F, Naeije M (2011) Risk factors for anterior disc 
displacement with reduction and intermittent locking in adolescents. J Orofac 
Pain 25:153–160 
7.  
Karacayli U, Mumcu G, Cimilli H, Sisman N, Sur H, Gunaydin Y (2011) The 
effects of chronic pain on oral health related quality of life in patients with 
anterior disc displacement with reduction. Community Dent Health 28:211–215 
8.  
Kumazaki Y, Kawakami S, Hirata A, Oki K, Minagi S (2016) Ipsilateral Molar 
Clenching Induces Less Pain and Discomfort than Contralateral Molar 
Clenching in Patients with Unilateral Anterior Disc Displacement of the 
Temporomandibular Joint. J Oral Facial Pain Headache 30:241–248. doi: 
10.11607/ofph.1405 
9.  
Lindfors E, Arima T, Baad-Hansen L, Bakke M, De Laat A, Giannakopoulos N, 
Glaros A, Guimarães A, Johansson A, Le Bell Y, Lobbezoo F, Michelotti A, 
Müller F, Ohrbach R, Wänman A, Magnusson T, Ernberg M (2019) Jaw 
Exercises in the Treatment of Temporomandibular Disorders—An International 
Modified Delphi Study. J Oral Facial Pain Headache 39:389–398. doi: 
10.11607/ofph.2359 
10.  
List T, Axelsson S (2010) Management of TMD: evidence from systematic 
reviews and meta-analyses. J Oral Rehabil 37:430–451. doi: 10.1111/j.1365-
2842.2010.02089.x 

13 
 
11.  
McNeely ML, Armijo Olivo S, Magee DJ (2006) A systematic review of the 
effectiveness of physical therapy interventions for temporomandibular 
disorders. Phys Ther 86:710–725 
12.  
Nagata K, Hori S, Mizuhashi R, Yokoe T, Atsumi Y, Nagai W, Goto M (2019) 
Efficacy of mandibular manipulation technique for temporomandibular 
disorders patients with mouth opening limitation: a randomized controlled trial 
for comparison with improved multimodal therapy. Journal of Prosthodontic 
Research 63:202–209. doi: 10.1016/j.jpor.2018.11.010 
13.  
Navi F, Kalantar Motamedi MH, Taheri Talesh K, Lasemi E, Nematollahi Z 
(2013) Diagnosis and Management of Temporomandibular Disorders. In: 
Kalantar Motamedi MH (ed) A Textbook of Advanced Oral and Maxillofacial 
Surgery. InTech 
14.  
Navi F, Motamedi MHK, TaheriTalesh K, Lasemi E, Nematollahi Z (2013) 
Diagnosis and Management of Temporomandibular Disorders. A Textbook of 
Advanced Oral and Maxillofacial Surgery. doi: 10.5772/55018 
15.  
Okeson JP (1988) Long-term treatment of disk-interference disorders of the 
temporomandibular joint with anterior repositioning occlusal splints. J Prosthet 
Dent 60:611–616. doi: 10.1016/0022-3913(88)90224-7 
16.  
Okeson JP (2019) Management of Temporomandibular Disorders and 
Occlusion - E-Book. Elsevier Health Sciences 
17.  
Schiffman E, Ohrbach R, Truelove E, Look J, Anderson G, Goulet J-P, List T, 
Svensson P, Gonzalez Y, Lobbezoo F, Michelotti A, Brooks SL, Ceusters W, 
Drangsholt M, Ettlin D, Gaul C, Goldberg LJ, Haythornthwaite JA, Hollender L, 
Jensen R, John MT, De Laat A, de Leeuw R, Maixner W, van der Meulen M, 
Murray GM, Nixdorf DR, Palla S, Petersson A, Pionchon P, Smith B, Visscher 
CM, Zakrzewska J, Dworkin SF (2014) Diagnostic Criteria for 
Temporomandibular Disorders (DC/TMD) for Clinical and Research 
Applications: Recommendations of the International RDC/TMD Consortium 
Network and Orofacial Pain Special Interest Group. J Oral Facial Pain 
Headache 28:6–27 
18.  
Wänman A, Marklund S (2020) Treatment outcome of supervised exercise, 
home exercise and bite splint therapy, respectively, in patients with 
symptomatic disc displacement with reduction: A randomised clinical trial. J 
Oral Rehabil 47:143–149. doi: 10.1111/joor.12888 
19.  
Wieckiewicz M, Grychowska N, Wojciechowski K, Pelc A, Augustyniak M, 
Sleboda A, Zietek M (2014) Prevalence and Correlation between TMD Based 
on RDC/TMD Diagnoses, Oral Parafunctions and Psychoemotional Stress in 
Polish University Students. Biomed Res Int 2014. doi: 10.1155/2014/472346 

14 
 
20.  
Wolfart S, Heydecke G, Luthardt RG, Marré B, Freesmeyer WB, Stark H, 
Wöstmann B, Mundt T, Pospiech P, Jahn F, Gitt I, Schädler M, Aggstaller H, 
Talebpur F, Busche E, Bell M (2005) Effects of prosthetic treatment for 
shortened dental arches on oral health-related quality of life, self-reports of 
pain and jaw disability: results from the pilot-phase of a randomized 
multicentre trial. Journal of Oral Rehabilitation 32:815–822. doi: 
10.1111/j.1365-2842.2005.01522.x 
21.  
Wright EF, Klasser GD (2019) Manual of Temporomandibular Disorders. John 
Wiley & Sons 
22.  
Wright EF, North SL (2009) Management and Treatment of 
Temporomandibular Disorders: A Clinical Perspective. J Man Manip Ther 
17:247–254