Prevalence of temporomandibular disorders discovered incidentally during routine dental examination using the Research Diagnostic Criteria for Temporomandibular Disorders

Accepted Manuscript Title: Prevalence of temporomandibular disorders discovered incidentally during routine dental examination using the research diagnostic criteria for temporomandibular disorders Author: Wael M. Talaat, Omar I. Adel, Saad Al Bayatti PII: DOI: Reference:

S2212-4403(17)31190-2 https://doi.org/10.1016/j.oooo.2017.11.012 OOOO 1889

To appear in:

Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology

Received date: Revised date: Accepted date:

5-7-2017 2-10-2017 4-11-2017

Please cite this article as: Wael M. Talaat, Omar I. Adel, Saad Al Bayatti, Prevalence of temporomandibular disorders discovered incidentally during routine dental examination using the research diagnostic criteria for temporomandibular disorders, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology (2017), https://doi.org/10.1016/j.oooo.2017.11.012. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Prevalence of temporomandibular disorders discovered incidentally during routine dental examination using the Research Diagnostic Criteria for Temporomandibular Disorders Wael M. Talaat, PhDa,b; Omar I. Adel, DDSc; Saad Al Bayatti, MScd a

Assistant Professor of Oral and Maxillofacial Surgery, Department of Oral and Craniofacial

Health Sciences, College of Dental Medicine, University of Sharjah, UAE, 27272. [email protected] b

Associate Professor of Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial

Surgery, Suez Canal University, Ismailia, Egypt. c

Clinical tutor, College of Dental Medicine, University of Sharjah, UAE, 27272.

[email protected] d

Lecturer of Oral Radiology, Department of Oral and Craniofacial Health Sciences, College of

Dental Medicine, University of Sharjah, UAE, 27272. [email protected] Corresponding author: Wael M. Talaat, PhD Assistant Professor of Oral and Maxillofacial Surgery Assistant Director for Training and Education College of Dental Medicine, University of Sharjah, UAE Tel: +971 65057605 Fax: +971 65057606 University Dental Hospital Sharjah, Room F125 P.O. Box: 27272 Email: [email protected]

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Disclosures: Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Conflicts of Interest: None Ethical Approval: Research Ethics Committee, University of Sharjah

Word count for the abstract: 199 Word count for the complete manuscript: 5917 Number of references: 49 Number of figures: 2 Number of tables: 8

Statement of Clinical Relevance: Temporomandibular disorders (TMD) can be discovered incidentally during routine dental examination. Dental practitioners have to screen patients for TMD and refer them for treatment as needed. This will improve the quality of care and enhance the patient’s quality of life.

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Abstract Objectives: To assess the prevalence of temporomandibular disorders (TMD) discovered incidentally during routine dental examination, identify disease patterns, and evaluate patients’ attitude toward accepting treatment. Study design: A total of 3009 subjects were examined at the University Dental Hospital Sharjah. Research Diagnostic Criteria for TMD (RDC/TMD) Axes I and II were used for assessment. Subjects with acute/serious dysfunction symptoms underwent cone-beam computed tomography (CBCT) examination. MRI was used to confirm the diagnosis of disc displacement. Results: Non-self-reported TMD prevalence was 10.8% (n=325). Among TMD patients, the disorders were diagnosed more in women (65.85%) (p<0.05), and between the ages of 25 and 45 (65.54%) (p<0.05). Axis I assessment revealed disc displacement with reduction (group IIa) was the most common (40.92%). Axis II chronic pain grade (CPG) showed 32.62% of TMD patients experienced chronic pain, whereas 66.77% had mild disability. Interest to pursue treatment was indicated by 92.31% of patients. CBCT and MRI assessment changed the primary diagnosis in 26.08% and 18.47% of cases, respectively. Conclusions: TMD screening during routine dental examination led to the diagnosis of non-selfreported TMD, most commonly related to disc displacement with reduction. Radiographic assessment was important to confirm TMD diagnosis. Patients diagnosed with TMD during dental screening expressed interest in pursuing treatment.

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Keywords: Temporomandibular Disorders; Temporomandibular Joint; Research Diagnostic Criteria for Temporomandibular Disorders; Prevalence; Routine dental examination; Disc displacement

Introduction Temporomandibular disorders (TMD) are a common and divergent combination of disorders that affect the muscular, soft tissue, and bony components of the temporomandibular joint (TMJ). The causes of TMD are variable, as are the clinical symptoms, which may include pain, clicking, limited opening, deviation of the mandible on opening and closing, headaches, earaches, and muscle tenderness. TMD is the most common cause of non-odontogenic pain in the orofacial region. The diagnosis of TMD often involves history taking, clinical examination, and imaging of the TMJ.1, 2 The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) are the most commonly used standardized diagnostic criteria for TMD and provide excellent reliability and validity.3,4 The RDC/TMD have two assessment components. Axis I includes a clinical examination of signs and symptoms supplemented with radiographic assessment, which leads to classifying TMD into three groups: Group I, Muscular Disorders (Ia myofascial pain; Ib myofascial pain with limited mouth opening); Group II, Disc Displacement (IIa disc displacement with reduction, IIb disc displacement without reduction with limited opening, IIc disc displacement without reduction without limited opening); and Group III, Arthralgia, Osteoarthritis, and Osteoarthrosis (IIIa arthraglia, IIIb osteoarthritis, IIIc osteoarthrosis). The radiographic analysis criteria for Axis I involve the use of MRI for the diagnosis of disc displacement by evaluating the disc position, and computed tomography for the diagnosis of osteoarthritis by analyzing bony alterations inside the joint. Axis II of the RDC/TMD is an evaluation of psychosocial dysfunction and pain-related disability, and assesses several TMD-

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related factors such as chronic pain grade, characteristic pain intensity, and disability. Axis II evaluation is important in predicting the treatment outcome as well as the chronicity of pain.3 Another diagnostic classification of TMD is that introduced by the American Academy of Orofacial Pain, which, according to the presenting symptoms and clinical examination, classifies TMD into muscular disorders and articular disorders. The articular group includes disc disorders, inflammatory disorders, osteoarthritis, condylar dislocation, ankylosis, and fractures.5 Clinical examination must be endorsed by different imaging modalities to confirm the diagnosis. Magnetic resonance imaging (MRI) is the radiographic modality of choice to evaluate the soft tissue components of the TMJ, where an accurate diagnosis of disc abnormalities would not be reached without supplementing the clinical examination with MRI. On the other hand, the RDC/TMD recommends computed tomography (CT) as the imaging modality of choice to assess the bony alterations associated with TMD. Recently, cone beam computed tomography (CBCT) has been suggested as an alternative to CT due to lower cost, lower radiation, similar diagnostic efficacy, and better access to equipment. CBCT is currently used to diagnose TMD involving bony alterations such as osteoarthritis.1–4 Prevalence of TMD varies significantly between different studies. This is related to differences in studied populations, methodologies, examination procedures, diagnostic criteria, and classifications.6 Some studies have assessed the prevalence of TMD-related pain in children and adolescents,7–10 and many investigations have assessed the prevalence of TMD in other general and specific populations.11–20 Patients might ignore TMD symptoms, which might be discovered only when TMJ examination is included in the patients’ screening protocol in dental practice. The prevalence and classification of non-self-reported TMD that is discovered incidentally during routine dental examination is missing in the literature. The aim of this study was to assess the prevalence of TMD discovered incidentally during routine dental examination at the University Dental Hospital Sharjah, identify disease patterns, and evaluate the patients’ attitude toward accepting or refusing treatment.

Materials and methods

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The study was conducted on patients attending the Oral Diagnosis and Urgent Care Clinic at the University Dental Hospital Sharjah, United Arab Emirates, between February 2017 and June 2017. A total of 3009 patients were examined during the initial screening. The patients were predominantly men (60.9%), Caucasians (73.4%), and young adults, between the ages of 25 and 45 years (36.7 ± 6.2) (61.2%). All patients underwent a comprehensive TMJ clinical examination as part of their routine dental, intra-oral, and extra-oral diagnostic examination procedure. When indicated, panoramic radiographs were acquired as part of the examination procedure to diagnose various conditions, including the initial screening for suspected TMD. All patients between the ages of 18 and 65 years old with symptoms of TMD identified during the screening procedures were further evaluated by an RDC/TMD-based diagnostic examination. These symptoms include TMJ pain, clicking, crepitus, limited mouth opening, limited lateral excursions of the mandible, deviation of the mandible on opening and closing, headaches, earaches, and muscle tenderness. Patients were excluded from the study if they had received previous TMD treatment or had approached the University Dental Hospital Sharjah with TMD as their chief complaint. Pregnant women were excluded to avoid any adverse effects from x-rays. All subjects were informed of the aim of the study, and they signed a formal consent prior to participation, which was approved by the University of Sharjah Research Ethics Committee. Clinical examination An RDC/TMD Axis I–based clinical examination and structured diagnosis of TMD was carried out. The initial TMJ clinical examination procedure was conducted by a clinical tutor as part of the screening at the Oral Diagnosis and Urgent Care Clinic. The clinical examination included palpation of the masticatory and cervical muscles to identify any areas of tenderness or sustained contraction. The joints were auscultated and palpated during mandibular motion, and joint sounds were identified as short duration sound (clicking) or long duration sound (crepitus). The pattern of opening was observed for deviation. The maximal mouth opening was measured as the interincisal distance between the upper and lower incisors, and lateral excursions were measured as the distance between the maxillary and mandibular midlines on moving the mandible to the right and left. Pain intensity was measured using the 10-point visual analog scale (VAS) (0 indicating the absence of pain, and 10 indicating the worst pain). TMJ clinical

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examination was again performed by one oral and maxillofacial surgeon who had specialized for over 12 years in the diagnosis and treatment of TMD. This examiner was blinded to the outcome of the initial screening procedure (performed by the clinical tutor) as well as to any related variables that were assessed in all questionnaires. Calibration of the examiners was achieved before the beginning of the study by allowing each examiner to evaluate the same 20 subjects independently. The results were then compared; any discrepancies were resolved by group discussion. Helkimo’s clinical dysfunction index (Di)21 (Table I) was used to qualify subjects for CBCT exposure, and only subjects with acute or serious dysfunction symptoms (group Di III) detected on clinical examination underwent CBCT examination of their TMJ. MRI was performed to confirm the diagnosis of disc displacement, with or without reduction, following the RDC/TMD-based clinical examination. Evaluation by CBCT All CBCT examinations were performed with GALILEOS 3D X-ray systems (SIRONA Dental Systems, York, PA, USA). Exposure parameters were uniform for all patients: tube voltage: 85 kV, exposure time: 3 seconds, tube current: 7 mA, effective dose: 75 mSv, voxel size: 150 mm (screen resolution 1366|768), field of view: 15 ×15 cm, and slice thickness 1.0 mm. The right and left joints were interpreted from the medial pole to the lateral pole in three planes: sagittal, coronal, and axial, observing the following radiographic criteria: Fattening: loss of an even convexity or concavity of the joint outlines; Osteophyte: local outgrowth of bone arising from a mineralized joint surface (Fig. 1); Ely’s cyst (sub-cortical cyst): rounded radiolucent area that may be just below the cortical plate or deep in trabecular bone; and Condylar surface irregularities (Fig. 2). The radiographic criteria were categorized as either present or not present. The distances from the deepest point on the concavity of the glenoid fossa to the highest point on the condyle in sagittal and coronal views were measured, and the mean of the last two readings was recorded for joint space measurement.22 Evaluation by MRI

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MRI examinations were conducted when TMJ internal derangement was suspected following the clinical examination. All examinations were performed using a 1.5 Tesla scanner (CHORUS 1.5T, ISOL Technology, Gyeonggi-do, South Korea) with a TMJ surface coil. Pulse sequences were obtained from all patients in closed and maximal open-mouth positions on corrected sagittal and coronal T1 weighted (500/16 ms); proton density, and T2 weighted (2000/80 ms) images. The imaging parameters were as follows: flip angle, 20 degrees; an 11 cm2 field of view; and a section thickness of 2 mm with 0.2 mm gap. The right and left joints were interpreted in closed and maximal open-mouth positions, observing any displacement in the articular disc with any evidence of recapture. MRI and CBCT image analysis and measurements were performed by an oral radiologist with a Master of Science in oral and maxillofacial radiology and a total of 28 years of experience. The oral radiologist was blind to the clinical examination outcome. The image analysis criteria of the RDC/TMD Axis I were used as the basis for radiographic assessment in this study.3 Each radiographic image was interpreted twice by the oral radiologist on separate occasions, with a 1week interval. Cases with doubtful findings at the second interpretation were decisively evaluated at a third occasion after a 1-week interval. RDC/TMD Axis II evaluation A validated questionnaire was used to assess the socioeconomic status of all subjects based on Axis II of RDC/TMD.6 The questionnaire analyzed different related factors such as selfperceived general health; self-perceived oral health; education; familial economic status; housing conditions, including type of housing and number of rooms used for sleeping; average monthly income; and social integration and cohesion. The chronic pain grade (CPG) scale, characteristic pain intensity (CPI) scale, and disability scale were assessed for each patient as components of RDC/TMD Axis II. The CPG scale was classified as grade 0: no pain in the past 6 months, grade I: low intensity pain, grade II: high-intensity pain, grade III: moderately limiting pain, and grade IV: severely limiting pain. The disability scale was graded by points: no disability = 0 points, mild disability = 1 to 2 points, moderate disability = 3 to 4 points, and severe disability = 5 to 6 points. The prevalence of headache and sleep/awake bruxism was also assessed.

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Following the clinical, radiographic, and Axis II evaluation, all data were collected and analyzed; thus, subjects were diagnosed with TMD and classified according to RDC/TMD Axis I. The patients included in this study were those in which there was agreement between the authors with respect to the final diagnosis. All subjects then answered a questionnaire about accepting or refusing treatment of their condition. TMD education was provided to all subjects. No treatment was offered to the patients within the premises of the study to avoid skewing their answers. Ethical aapproval for this study was obtained from the Research Ethics Committee at the University of Sharjah. The Helsinki Declaration guidelines were followed in this investigation. Statistical analysis Data analysis was performed using the statistical package for social sciences, SPSS version 16.0. Categorical variables were generally described by frequency and percentages. The different RDC/TMD Axis I groups and the CPG of Axis II groups were analyzed using Pareto Analysis with the application of a z-test of two proportions to detect any statistically significant differences between the groups. The chi-square test of independence was used to determine the association between the two categorical variables, the RDC/TMD Axis I and the CPG of Axis II, and between the RDC/TMD Axis I and the Disability of Axis II. The Mann–Whitney U-test was used to assess the socioeconomic factors. A p value <0.05 was considered statistically significant, whereas a p value <0.01 was considered statistically highly significant.

Results TMD prevalence within the evaluated sample was 10.8% (n = 325). TMD was found significantly more in women (65.85%) (p <0.05), and between the ages of 25 and 45 years (65.54%) (p <0.05). The results of Axis I assessment of the RDC/TMD showed that disc displacement with reduction (group IIa) was the most common diagnosis (40.92%), followed by myofascial pain (group Ia) (17.54%), disc displacement without reduction and with limited opening (group IIb) (15.69%), osteoarthritis (group IIIb) (11.69%), myofascial pain with limited opening (group Ib)

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(9.23%), disc displacement without reduction and without limited opening (group IIc) (4.62%), osteoarthrosis (group IIIc) (0.31%), and, finally, arthralgia (group IIIa) (0.00%). Pareto analysis with the application of the z-test of two proportions was done to detect any statistically significant differences between the prevalence of different Axis I groups; the differences were found to be highly statistically significant between group IIa and group Ia, group IIIb and group IIC, and group IIc and group IIIc (p <0.01) (Table II). The CPG of RDC/TMD Axis II evaluation showed that 32.62% of the examined subjects experienced some degree of chronic pain. The most common CPG grade was grade 0 (67.38%), followed by grade II (16.92%), grade I (8.92%), grade III (4.62%), and grade IV (2.15%). Pareto analysis with the application of a z-test of two proportions was done to detect any statistically significant difference between the CPG groups; the differences were found to be highly statistically significant between grade 0 and grade II and between grade II and grade I (p <0.01) (Table III). According to the CPG of RDC/TMD Axis II and its relation to Axis I classification, the most common CPG for group Ia was grade 0 (61.4%); for group Ib grade 0 and grade II equally (33.3%); for group IIa grade 0 (82.0%); for group IIb grade 0 (58.8%); for group IIc grade 0 (80.0%); for group IIIb grade 0 (60.5%), and for group IIIc grade III (100.0%). The relationship between the CPG and Axis I groups was highly significant (p <0.001) (Table IV). The most common level of characteristic pain intensity (CPI) was level 0 (67.38%), followed by level 5 (7.08%) (Table V). The assessment of disability level evaluated by Axis II showed that 46 patients had no disability (14.15%), 217 patients had mild disability (66.77%), 55 patients had moderate disability (16.92%), and 7 patients had severe disability (2.15%). The highest incidence of severe disability was found in group IIIb (13.2%). The relationship between the disability level and Axis I groups was highly significant (p <0.01) (Table VI). Short-duration TMJ sounds, identified as clicking, were found in 224 (68.92%) of the patients; right-side clicking was identified in 75 (23.08%) of the patients, left-side clicking was identified in 92 (28.31%) of the patients , and bilateral clicking was identified in 57 (17.54%) of the patients. Long-duration sounds, identified as crepitus, were found in 99 (30.46%) of the

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patients, in whom right-side crepitus was identified in 9 (2.77%) of the patients, left-side crepitus was identified in 23 (7.08%) of the patients, and bilateral crepitus was identified in 67 (20.62%) of the patients. The analysis of headache and bruxism by RDC/TMD Axis II revealed that headache was present in 51.69% of patients, and sleep/awake bruxism was present in 64.3%. All patients diagnosed with TMD (n = 325) completed a questionnaire to evaluate their socioeconomic status. No statistically significant differences were observed between the CPI of the different socioeconomic variables (Table VII). The results of the questionnaire about accepting or refusing treatment showed that 300 (92.31%) of the patients were interested in pursuing treatment of their condition, whereas 7.69% (n = 25) were not interested. The CBCT evaluation of qualified subjects (n = 46) with group Di III according to Helkimo’s clinical dysfunction index showed that CBCT detected at least one radiographic sign in 42 patients. The most common radiographic sign observed on CBCT was Ely’s cyst (43.48%), followed by condylar surface irregularity (36.96%) (Table VIII). The CBCT evaluation led to a change in the primary diagnosis that was concluded after the clinical examination in 26.08% of cases, whereas MRI evaluation led to a change in the primary diagnosis in 18.47% of cases.

Discussion Currently, dentists are considered the primary care providers for TMD, because they have the necessary training to diagnose and treat these complex disorders properly. In addition, the United States court system appraises TMD to be within the scope of the practice of dentistry.23 Accordingly, it is the duty of every dental practitioner to screen all patients for TMD to detect any signs or symptoms of these disorders. The screening should include history, clinical examination, consultation, and referral as needed. This approach might spare patients from possible disease progression and help relieve TMD symptoms, including the commonly undiagnosed headache. Thorough investigation of the signs and symptoms recognized during screening might reveal advanced forms of the disease. Another important benefit would be the

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promotion of TMD public education, which is crucial, considering the increasing prevalence of the disease.23–25 In our study, the overall TMD prevalence was 10.8%. In one study that evaluated TMD as a cause of orofacial pain among other causes in the United States, 5.3% of the population suffered from orofacial pain due to TMD, whereas pain of odontogenic origin was more frequent (12.2%).11 A study in Brazil found that 37.5% of the population suffered from at least one TMD symptom. This was a questionnaire-based population study, using five questions that focused on TMD symptoms.12 Studies assessing the prevalence of TMD signs and symptoms in college students found that 41.3% to 68.6% of students suffered from at least one sign or symptom of TMD.13–16 Two of these investigations were anamnestic, questionnaire-based studies,13,15 whereas the other two studies used clinical examination for the diagnosis in addition to the questionnaires.14,16 Other epidemiological studies found that at least one TMD sign was present in 40% to 75% of the population, whereas at least one TMD symptom was present in 33% of the population.26 A study on the prevalence of TMJ disc displacement in a pre-orthodontic adolescent sample evaluated the TMJ of 75 boys and 119 girls by means of MRI. A total of 138 subjects had no signs or symptoms, but 56 subjects suffered from TMD signs and symptoms. This report found normal joints in only 50% of boys and in 23%–29% of girls. The rest of the study population presented with different degrees of slight to full disc displacement with or without a change in morphology. On the other hand, 82% of patients presenting with pain and functional disturbance of their TMJ had displaced discs when examined with magnetic resonance imaging. The overall prevalence of symptomatic disc displacement or internal derangement ranged between 20% and 30%.27 An epidemiologic survey reported that 20% to 25% of the population has symptoms of TMD, whereas only 3% to 4% of the population (less than one-fifth of those who exhibit symptoms) seek treatment.28 This means that an average of 18% to 19% of the population might have undiagnosed TMD, and the chances of having their disorders properly managed are very low, because they are not seeking treatment. The TMD prevalence reported in our study was lower than that reported in several other studies.12–16,26–28 This might be because our study assessed the non-self-reported TMD prevalence, whereas patients with TMD as their chief complaint were excluded.

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The significant variation between the reported prevalence of TMD in different studies is attributed to differences in populations, methodologies, examination procedures, and diagnostic criteria,6 but many of these studies also used questionnaires as their sole research tool without any radiographic confirmation of the primary diagnosis and, in some cases, even without clinical examination. The absence of an agreed-upon worldwide definition of TMD may add to this problem. TMD prevalence may thus be overestimated in several studies. Assessing the TMD prevalence by using both clinical and radiographic examination is expected to provide more reliable results. Research assessing the value of CBCT in the diagnosis and management of TMD showed that the use of CBCT led to changes in the primary diagnosis of TMD in more than half the patients. In this study, the primary diagnosis was reached through history, clinical examination, and orthopantomogram.29 In our study, the use of CBCT and MRI led to changes in the primary diagnosis in 26.08% and 18.47% of cases, respectively. This confirms the value of CBCT and MRI in reaching an accurate diagnosis of TMD when bony or soft-tissue changes are suspected. This should be achieved by adopting reliable and consistent image analysis criteria in all prevalence studies, so that the results of different studies can be compared. Although the panoramic radiograph is of limited value in the process of diagnosing TMD, it might be useful for the detection of the significant bony alterations during the initial screening.3 The results of Axis I assessment in our study showed that disc displacement with reduction (group IIa) was the most common abnormality (40.92%), followed by myofascial pain (group Ia) (17.54%), and then disc displacement without reduction and with limited opening (group IIb) (15.69%). This was not in agreement with another study, which reported myofascial pain with or without limitation of opening (groups Ia and Ib) as the most prevalent (29.5%), whereas disc displacement with reduction (group IIa) was found in only 6.5% of the population, and disc displacement without reduction (groups IIb and IIc) was rare (1.4%).30 Although this study had a large sample size, its clinical examination was not augmented by any radiographs. In a systematic review of Axis I epidemiologic findings, the prevalence of group I in general populations was found to be 45.3%, 41.1% for group II, and 30.1% for group III. In a community-based study, disc displacement with reduction was the most common diagnosis, which is in accordance with our findings.31 A study applying the Finnish version of the RDC/TMD Axis 1 found the prevalence for group I, II, and III to be 13.3%, 19.9%, and 4%, respectively.32 The prevalence of group IIa in a study assessing Axis I clinical subtypes in an

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Andalusian health care service was 39.7% and 42.8% for the left and right TMJ, respectively, which was similar to that found in our study.33 The CPG of RDC/TMD Axis II evaluation showed that 32.62% of the examined subjects felt some degree of chronic pain. These results are in agreement with another study, which found 36.2% of the population with some degree of TMD pain; however, our results showed that mild disability was the most prevalent in our patients (66.77%), whereas no disability was the most prevalent in their population (60.3%).30 Another study found the majority of patients seeking treatment for TMD had low or no disability, whereas severely limiting disability was found in only 5.4% of patients, which is in agreement with our results (2.15%).34 It was noted in the present study that TMD pain is often overlooked by patients and frequently mistaken for pain due to dental or ear origin, which is a known fact due to anatomic considerations. The prevalence of joint sounds has varied among studies, ranging from 9.9%30 to 25%35 to 51.2%,36 whereas in our investigation, clicking was found in 68.92% of patients and crepitus in 30.46%. This variability might be due to inter-examiner reliability and lack of calibration in different investigations.37 The literature is in favor of considering disc displacement rather than muscular disorders the main cause of joint sounds. Headache and sleep/awake bruxism are common conditions usually associated with TMD. In our study, the prevalence of headache was 51.69%, which is in accordance with that reported in the literature (55.5% to 67.3%).39–41 The prevalence of bruxism was 64.3%, in agreement to another study that suggested that bruxism is strongly related to muscular rather than articular disorders.42 There were no statistically significant differences between the CPI of the evaluated socioeconomic variables. These results are in accordance with other community-based studies.44,45 This is commonly attributed to the fact that research tends to assess TMD prevalence in subjects with similar socioeconomic status. Another reason might be the impossibility of excluding stress from the daily life of subjects in the higher socioeconomic classes.45 Although no treatment was offered to patients diagnosed with TMD in this study, 92.31% of patients showed interest in pursuing treatment for their condition, based on their response to the provided questionnaire. A study has shown that only 2.7% of the patients diagnosed with TMD are aware of their condition.35 In spite of the fact that not all TMD patients require

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treatment, they should at least be alerted, because these disorders are often progressive. In 1979, Solberg et al.43 examined the prevalence of mandibular dysfunction in young adults and found that 20% of patients diagnosed with TMD desired to be treated. The authors suggested that the number of patients seeking care for their TMD would increase when more focus on public education has been implemented. Recently, another study found that 47% of patients reported that they needed treatment of their TMD.6 One possible explanation for the higher percentage of patients concerned with treating their TMD in our research is that the study was based in a dental hospital setting providing free treatment, which may generate a feeling of comfort and security to the patients. CBCT is currently regarded as an essential tool for the accurate diagnosis of TMD.22,29 For ethical considerations, only patients with serious symptoms of dysfunction were qualified for CBCT evaluation in this study. The most common radiographic signs seen were Ely’s cyst (43.48%) and condylar surface irregularities (36.8%). This was in partial agreement with our previous study, in which condylar surface irregularities were found in 43.47% of TMD patients. However, these results should be interpreted with caution, because the results might change if CBCT evaluation were performed for patients with minor and moderate dysfunction, in whom the adaptive bony alterations may be more prevalent. Despite the reported high prevalence of TMD in general, and the identification of advanced forms of these disorders in patients who did not seek treatment, the attention given to these disorders by educational institutions and health authorities is still not sufficient. Currently, dental graduates are not getting the necessary training to diagnose TMD efficiently.46 Also, screening for TMD is not yet recognized as an element of the initial dental screening. Referring TMD patients to a trained specialist after spotting the disorder would significantly improve the quality of care provided and enhance the patient’s quality of life as well. Although excellent results have been reported in treatment of TMD,47–49 the currently available guidelines for the initial diagnosis are still unreliable, especially those concerning the indications for radiographic assessment. In conclusion, TMD screening during routine dental examination was successful in diagnosing non-self-reported TMD.The prevalence of non-self-reported TMD was 10.8%. TMD was diagnosed predominantly in women, and between the ages of 25 and 45 years. Disc

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displacement with reduction was the most common Axis I subtype diagnosed. The prevalence of chronic pain grade and disability was comparable to that reported in the literature. Radiographic assessment was important to confirm TMD diagnosis. The use of CBCT and MRI led to a change in the primary diagnosis in 26.08% and 18.47% of cases, respectively. A large majority of patients diagnosed with TMD expressed interest in pursuing treatment for their conditions. This emphasizes the need to attract the attention of the concerned educational institutions and health authorities to these common disorders, with an aim of training undergraduate students to screen and diagnose TMD, refining the current guidelines for the diagnosis of TMD, and enforcing the inclusion of TMD screening in the process of routine dental examination.

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30- P.S. Progiante, M.P. Pattussi, H.P. Lawrence, S. Goya, P.K. Grossi, M.L. Grossi, Prevalence of Temporomandibular Disorders in an Adult Brazilian Community Population Using the Research Diagnostic Criteria (Axes I and II) for Temporomandibular Disorders (The Maringá Study), Int. J. Prosthodont. 28 (2015) 600-609. 31- D. Manfredini, L. Guarda-Nardini, E. Winocur, F. Piccotti, J. Ahlberg, F. Lobbezoo , Research diagnostic criteria for temporomandibular disorders: A systematic review of axis I epidemiologic findings. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 112 (2011) 453– 462. 32- M.A. Rantala, J. Ahlberg, T.I. Suvinen, A. Savolainen, M. Könönem, Symptoms, signs and clinical diagnoses according to the research diagnostic criteria for temporomandibular disorders among Finnish multiprofessional media personnel, J. Orofac. Pain. 17 (2003) 311–316. 33- A. Blanco-Hungría, A. Blanco-Aguilera, E. Blanco-Aguilera, et al, Prevalence of the different Axis I clinical subtypes in a sample of patients with orofacial pain and

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43- W.K. Solberg, M.W. Woo, J.B. Houston, Prevalence of mandibular dysfunction in young adults, J. Am. Dent. Assoc. 98 (1979) 25–34. 44- R.J. Martins, A.R. Garcia, C.A. Garbin, M.L. Sundefeld, The relation between socioeconomic class and demographic factors in the occurrence of temporomandibular joint dysfunction, Cien. Saude. Colet. 13 (2008) 2089-2096. 45- V.V. Mello, A.C. Barbosa, M.P. Morais, S.G. Gomes, M.M. Vasconcelos, F. Caldas Júnior Ade, Temporomandibular disorders in a sample population of the Brazilian northeast. Braz. Dent. J. 25 (2014) 442-46. 46- S.V. Carrara, C.R. Conti Paulo, J.S. Barbosa, Statement of the 1st Consensus on Temporomandibular Disorders and Orofacial Pain, Dental. Press. J. Orthod. 15 (2010) 114-120. 47- W. Talaat , M.M. Ghoneim, M. Elsholkamy, Single-needle arthrocentesis (Shepard cannula) vs. double-needle arthrocentesis for treating disc displacement without reduction, Cranio 34 (2016) 296-302. 48- S. Barkin, S. Weinberg, Internal derangements of the temporomandibular joint: the role of arthroscopic surgery and arthrocentesis, J. Can. Dent. Assoc. 66 (2000) 199–203. 49- D. Manfredini, Fundamentals of TMD management, in: D. Manfredini (Ed), Current concepts on temporomandibular disorders, Quintessence Publishing, Berlin, 2010, pp. 305-317.

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Figure legends Figure 1: Osteophyte shown on CBCT Figure 2: Condylar surface irregularities, bone remodeling and Ely’s cyst shown on CBCT

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Table I Helkimo’s clinical dysfunction index

1. TMJ function impairment Smooth movement without TMJ sounds and deviation on

0

opening or closing movements ≤2 mm TMJ sounds in one or both joints and/or deviation ≥2 mm

1

on opening or closing movements Locking and/or luxation of the TMJ

5

2. Muscle tenderness during palpation No pain on palpation of masticatory musculature

0

Tenderness to palpation of masticatory musculature in 1–3

1

palpation sites Tenderness to palpation in four or more sites of the masticatory

5

musculature 3. TMJ pain during palpation No tenderness to palpation

0

Tenderness to palpation laterally

1

Tenderness to palpation posteriorly

5

4. Pain during mandibular movement No pain on movement

0

Pain in association with one movement

1

Pain in association with two or more movements

5

5. Range of mandibular mobility

A. Maximum opening of mouth >40 mm

0

30–39 mm

1

<30 mm

5

B. Maximum lateral movement to the right ≥7 mm

0

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4–6 mm

1

0–3 mm

5

C. Maximum lateral movement to the left ≥7 mm

0

4–6 mm

1

0–3 mm

5

≥7 mm

0

4–6 mm

1

0–3 mm

5

Sum A + B + C + D

0

0

1–4

1

5–20

5

D. Maximum protrusion

Sum of 1 + 2 + 3 + 4 + 5

Di

Di 0: 0 point–absence of clinical symptoms; Di I: 1 to 4 points–mild dysfunction symptoms; Di II: 5 to 9 points–moderate dysfunction symptoms; Di III: 10 to 25 points–acute/serious dysfunction symptoms.

Table II Pareto analysis with the application of a z-test of two proportions to detect any statistically significant differences between Axis I groups: group Ia = myofascial pain, group Ib = myofascial pain with limited opening, group IIa = disc displacement with reduction, group IIb = disc displacement without reduction and with limited opening, group IIc = disc displacement without reduction and without limited opening, group IIIa = arthralgia, group IIIb = TMJ osteoarthritis, group IIIc = TMJ osteoarthrosis Axis I groups IIa

Ia

P1

P2

z

P value

40.92%

17.54%

6.55

<0.001**

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Ia

IIb

17.54%

15.69%

0.63

0.527

Ia

IIIb

17.54%

11.69%

2.11

0.035*

IIb

IIIb

15.69%

11.69%

1.48

0.138

IIb

Ib

15.69%

9.23%

2.49

0.013*

IIIb

Ib

11.69%

9.23%

1.03

0.305

IIIb

IIc

11.69%

4.62%

3.30

<0.001**

Ib

IIc

9.23%

4.62%

2.32

0.020*

IIc

IIIc

4.62%

0.31%

3.54

<0.001**

* Statistically significant from the compared group and all other groups with smaller proportions ** Highly statistically significant from the compared group and all other groups with smaller proportions

Table III Pareto analysis with the application of a z-test of two proportions to detect any statistically significant differences between the CPG grades. Grade 0 = no pain in the past 6 months, grade I = low-intensity pain, grade II = high-intensity pain, grade III = moderately limiting, grade IV= severely limiting CPG grade

P1

P2

z

P Value

Grade 0

Grade II

67.38%

16.92%

13.03

<0.001**

Grade II

Grade I

16.92%

8.92%

3.04

0.002**

Grade I

Grade III

8.92%

4.62%

2.19

0.029*

Grade III

Grade IV

4.62%

2.15%

1.74

0.083

* Statistically significant from the compared group and all other groups with smaller proportions ** Highly statistically significant from the compared group and all other groups with smaller proportions

Table IV Relationship between CPG of Axis II and DRC/TMD Axis I groups RDC/TMD Axis

CPG

Total

P Value

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I

Grade

Grade I Grade

0 I (Ia + Ib)

II 45

13

Grade

Grade

III

IV

18

51.72% 14.94%

8

3

20.69%

9.20%

3.45%

II

151

13

31

3

1

(IIa + IIb + IIc)

75.88%

6.53%

15.58%

1.51%

0.50%

III

23

3

6

4

3

7.69%

15.38%

10.26%

7.69%

29

55

15

7

(IIIa + IIIb + IIIc) 58.97% Total

219

<0.001** 87

199

39 325

** Highly significant

Table V Prevalence of characteristic pain intensity (CPI) RDC/TMD Axis II: CPI

Level

N (%)

Level 0

219 (67.38%)

Level 1

0 (0%)

Level 2

10 (3.08%)

Level 3

17 (5.23%)

Level 4

19 (5.85%)

Level 5

23 (7.08%)

Level 6

15 (4.62%)

Level 7

6 (1.85%)

Level 8

9 (2.77%)

Level 9

2 (0.62%)

Level 10

5 (1.54%)

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Table VI Relationship between disability of Axis II and DRC/TMD Axis I groups

RDC/TMD Axis I

Disability Moderate Severe Total

No disability

Mild

I

17

61

9

0

(Ia + Ib)

19.54%

70.11%

10.34%

0.00%

II

28

139

30

2

(IIa + IIb + IIc)

14.07%

69.85%

15.08%

1.01%

III

1

17

16

5

(IIIa + IIIb + IIIc)

2.56%

43.59%

41.03%

12.82%

46

217

55

7

Total

87

P Value <0.001**

199

39 325

** Highly significant

Table VII Relationship among characteristic pain intensity (CPI), perceived health-related variables, and socioeconomic status Variable

N (%)

CPI

P-value

Mean ± SD Q1. How your

a. Very bad

5 (1.53%)

6 ± 2.422

general health is:

b. Bad

5 (1.53%)

5 ± 2.183

c. Good

188

0.627 ± 2.430

d. Very good

(57.84%)

4.611 ± 2.238

0.128

126 (38.76%) Q2. How do you

a. Very bad

18 (5.53%)

3 ± 2.072

think your oral

b. Bad

69 (21.23%)

2.913 ± 2.19

health is:

c. Good

208

0.730 ± 2.184

d. Very good

(64.00%)

5.602 ± 2.640

0.645

30 (9.23%) Q3. What is your

a. None

21 (6.46%)

4.14 ± 2.30

level of

b. Primary school

46 (14.15%)

2.15 ± 2.572

Page 27 of 31

education?

c. Secondary school

88 (27.07%)

1.86 ± 2.89

d. Degree

170

1.08 ± 2.492

0.211

(52.30%) Q4. How do you

a. Not good

64 (19.69%)

1.57 ± 2.671

rate your income?

b. Moderate

137

1.74 ± 2.628

(42.15%)

0.920

c. Good

111

1.49 ± 2.260

d. Very good

(34.15%)

2.92 ± 2.562

13 (4.00%)

Q5. You are living

a. Parents

41 (12.61%)

1.09 ± 2.984

with:

b. Spouse

113

2.37 ± 2.321

(34.76%) c. Sharing with friends

1.00

106

1.39 ± 2.746

(32.61%)

1.12 ± 2.834

d. Alone

65 (20.00%)

Q6. How many

a. One

145

1.73 ± 2.874

rooms are there in

b. Two

(44.61%)

1.28 ± 2.952

your house?

Q7. You are:

88 (27.07%)

1.00

c. Three

46 (14.15%)

1.71 ± 2.877

d. More than three

46 (14.15%

1.95 ± 2.836

a. Single

108

1.35 ± 2.940

b. Married

(33.23%)

1.21 ± 2.963

212

0.211

(65.23%) c. Divorced

3 (0.92%)

3 ± 1.00

d. Widowed

2 (0.61%)

4.50 ± 1.22

Page 28 of 31

Table VIII Radiographic signs depicted on CBCT Right TMJ

Left TMJ

Total

N (%)

N (%)

N (%)

Flattening

4 (8.70%)

5 (10.90%)

9 (19.57%)

Osteophyte

6 (13.04%)

2 (4.35%)

8 (17.39%)

Ely’s cyst

12 (26.08%)

8 (17.39%)

20 (43.48%)

Condylar surface

9 (19.57%)

8 (17.39%)

17 (36.96%)

Total

31 (67.40%)

23 (50.00%)

Joint space

5.07  2.05

5.10  2.26

5.56  2.09

5.82  2.39

irregularity

Coronal in mm (Mean  SD) Joint space Sagittal in mm (Mean  SD)

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