Temporomandibular Disorders Research Research Articles

The challenge of ecological validity in temporomandibular disorders research.

To review the ecological validity of outcomes from current research involving temporomandibular disorders (TMDs), with an emphasis on chronic myofascial pain and the precocious development of degenerative disease of the temporomandibular joint (TMJ). Current approaches used to study TMDs in terms of neuromechanics, masticatory muscle behaviours, and the dynamics of the autonomic nervous system (ANS) were assessed for ecological validity in this review. In particular, the available literature was scrutinized regarding the effects of sampling, environmental and psychophysiological constraints and averaging data across biological rhythms. Validated computer-assisted numerical modelling of the neuromechanics used biological objective functions to accurately predict muscle activation patterns for jaw-loading tasks that were individual-specific. With respect to masticatory muscle behaviour, current findings refute the premise that sustained bruxing and clenching at high jaw-loading magnitudes were associated with painful TMDs such as myofascial pain. Concerning the role of the ANS in TMDs, there remains the need for personalized assessments based on biorhythms, and where the detection of dysregulated physiologic oscillators may inform interventions to relieve pain and restore normal function. Future human research which focuses on TMD myofascial pain or the precocious development and progression of TMJ degenerative joint disease requires experimental designs with ecological validity that capture objectively measured data which meaningfully reflect circadian and ultradian states.

The 50 most-cited articles on temporomandibular disorders: A bibliometric analysis.

Temporomandibular disorders (TMD) are musculoskeletal conditions involving masticatory muscles and temporomandibular joints. Bibliometric analysis has been introduced as a new method for collecting and analyzing information on scientific articles. The aim of this study was to identify the 50 most cited articles on TMD, performing a bibliometric analysis of the identified papers to favor research and clinical practice. On December 17, 2021 a systematic research was performed to find all papers on TMD published in the literature. The Incites Journal Citation Reports dataset and Scopus database was used to obtain bibliometric indexes of the authors and metrics data of the journals, including Impact Factor, Eigenfactor Score, and Normalized Eigenfactor. VOSviewer was used to visualize the keyword mapping networking, with the nodes standing for keywords and the edges for keyword relationships. Out of 24372 papers obtained by the search strategy, the 50 most cited articles on TMD were analyzed. The paper with the highest number of citations (n= 3020) was on TMD research diagnostic criteria. Rate of citations per year collected by the 50 most cited articles on TMD has been increasing over time (from 627 in 2006 to 1483 in 2021). Most of them were cross-sectional studies (n= 20; 40.0%) and narrative reviews (n= 14; 28.0%). This bibliometric study showed an increasing number of citations for articles on TMD, testifying a high interest in the last years. Starting from this analysis, future studies might provide high-quality evidence on TMD management.

Remarks on "Temporomandibular Disorders: Priorities for Research and Care": how will Chile advance?

Temporomandibular disorders (TMDs) are complex multi-system disorders for which common traditional dental-centric approaches to research and care unfortunately continue to prevail. A committee appointed by the National Academies of Sciences, Engineering and Medicine (NAM) of the United States of America summarized important recommendations regarding the urgent need to transform, from the predominantly biomedical model, the research, professional education/training, and patient care for TMDs into the biopsychosocial model that is standard in the rest of pain medicine. The release of the Consensus Study Report identifies eleven short-term and long-term recommendations regarding gaps and opportunities oriented towards the situation in the US, which are equally applicable to the situation in Chile. The first four recommendations focus on basic and translational research, public health research and strengthening clinical research. The next three recommendations concern risk assessment, diagnostics, and dissemination of clinical practice guidelines and care metrics to improve patient care and expand its access. Recommendations eight to ten propose Centers of Excellence for Temporomandibular Disorders and Orofacial Pain Treatment, improving professional school education, and expanding specialized continuing education for healthcare providers. The eleventh recommendation focuses on patient education and stigma reduction. This article highlights the published recommendations and addresses what should be considered by Chilean professionals, as a first step of a major effort to shift TMD research, treatment, and education paradigms for the years to come.

Publication performance and trends in temporomandibular disorders research: A bibliometric analysis

BackgroundTemporomandibular disorders (TMD) are common, can be both painful and non-painful, and encompass various conditions affecting the temporomandibular joint, the masticatory muscles or both TMD. Therefore, the purpose of this bibliometric analysis was to synthetically analyze citation performance in TMD, to address a more innovative method including details of article title, author keyword, KeyWords Plus, and abstracts. Material and methodsData used in this study were retrieved from the Clarivate Analytics Web of Science Core Collection, the online version of the Science Citation Index Expanded (SCI-EXPANDED) between 1992 and 2021. The distribution of key words in the article title and author‑selected keywords were used to evaluate research trends. ResultsOf the 7,228 documents in SCI-EXPANDED, 6,138 documents met all inclusion criteria and were included in the final analysis, of which 4,945 were articles. The present bibliometric analysis of the articles published in the research filed of TMD revealed that orofacial pain, bruxism, chronic pain, and myofascial pain are the most commonly used keywords by the authors. Further, over the last 30 years 4,945 articles are published in the field of TMD, and the far most frequently cited study was published 8 years ago and handles the diagnostic criteria of TMD.The USA and Brazil were top two ranking productive countries of publication on TMD. The most productive journal was Journal of Oral Rehabilitation, followed by Cranio-The Journal of Craniomandibular & Sleep Practice and Journal of Oral & Facial Pain and Headache. The most productive authors were P. Svensson, R. Ohrbach, and F. Lobbezooas. The most productive institutes were Sao Paulo University (Brazil), Malmo University (Sweden), and Washington university (USA) ConclusionBased on the outcome of this bibliometric study, the authors hope that both clinicians and researchers will have information to shape their future research focus, finding prominent institutions in their nearby area, or even to be stimulated to initiate new international or even multinational collaborations.

Recently Released Report by Major Scientific Academy Proposes Significant Changes in Understanding and Managing Temporomandibular Disorders

A recent Consensus Study Report1 of The National Academies of Sciences, Engineering, and Medicine (NASEM) recommends that the field of temporomandibular disorders (TMDs) must be totally changed in terms of biomedical research, professional education/training, and patient care. Recent research demonstrates that TMDs are complex multi-system disorders, which points to the need for a different, patient-centered, interprofessional approach to TMD research and treatment. Therefore, traditional dental-centric approaches to research and treatment of TMDs must be modernized to align with insights gained from new scientific discoveries.

Animal Models of Temporomandibular Disorder.

Temporomandibular disorders (TMD) are a group of diseases in the oral and maxillofacial region that can manifest as acute or chronic persistent pain, affecting millions of people worldwide. Although hundreds of studies have explored mechanisms and treatments underlying TMD, multiple pathogenic factors and diverse clinical manifestations make it still poorly managed. Appropriate animal models are helpful to study the pathogenesis of TMD and explore effective treatment measures. At present, due to the high cost of obtaining large animals, rodents and rabbits are often used to prepare TMD animal models. Over the past decade, various animal models have been intensively developed to understand neurobiological and molecular mechanisms of TMD, and seek effective treatments. Although these models cannot carry out all clinical features, they are valuable in revealing the mechanisms of TMD and creating curative access. Currently, there are multitudinous animal models of TMD research. They can be constructed in different means and summarized into four ways according to the various causes and symptoms, including chemical induction (intra-articular injection of ovalbumin, collagenase, formalin, vascular endothelial growth factor, intramuscular injection of complete Freund’s adjuvant, etc.), mechanical stress stimulation (passive mouth opening, change of chewing load), surgical operation (partial disc resection, joint disc perforation) and psychological stress induction. Here, we summarize and discuss different approaches of animal models for determining neurophysiological and mechanical mechanisms of TMD and assess their advantages and limitations, respectively.

Mapping research trends of temporomandibular disorders from 2010 to 2019: A bibliometric analysis.

Because of various clinical manifestations and complicated courses, temporomandibular disorders (TMDs) are difficult to treat. Current knowledge about this disease remains insufficient for precise treatment after diagnosis. The objective of this study is to obtain and map the overall literature trends and most cited keywords in TMDs research. Many indicators, including annual number of publications, country distribution, global cooperations, author contributions, original journals, cited references and keywords, were calculated and evaluated using VOSviewer v.1.6.13, which visualised many results, from the WoSCC database. A total of 3121 papers on TMDs research were retrieved from 2010 to 2019. The United States produced the most articles published, but the most productive institution was the University of Sao Paulo (Brazil). Researchers and institutions conducting TMDs research have shown a very widespread and close connection. TMDs have been studied worldwide by many research centres. Professor Svensson P was the most published researcher in TMDs research and the Journal of Oral Rehabilitation published the most TMDs research articles. The top cited references mainly presented diagnostic criteria of TMDs. The most cited keywords formed clusters: (a) Anatomicalfactorof TMDs, (b) Symptoms of TMDs and (c) RDC/TMD, the risk factors, biopsychosocial factors and epidemiology of TMDs. The research results provide very valuable data for a thorough understanding of the research status of TMDs and demonstrated international cooperation.

Evaluation of the condylar position in younger and older adults with or without temporomandibular symptoms by using cone beam computed tomography

Statement of problemRecent studies in young adults have questioned the influence of discrepancies between central and maximal intercuspal positions in temporomandibular disorders (TMDs). However, whether this finding was because this type of etiologic agent requires time for the development of changes in the condylar position is unclear. PurposeThe purpose of this clinical study was to use cone beam computed tomography (CBCT) to evaluate the presence or absence of discrepancies between the centric relation (CR) and maximum intercuspation (MI) in younger and older adults in populations with or without TMDs. Material and methodsThe sample was composed of 80 volunteers, 40 younger individuals aged 18 to 25 years (27 women and 13 men), half with and half without TMD symptoms, and 40 older participants aged 35 to 50 years (30 women and 10 men), half with and half without TMD symptoms. The TMD symptoms were diagnosed by using the diagnostic (standard) criteria for TMD research (RDC/TMD). Two CBCT scans were performed on each participant, one in MI and another in CR. Measurements of the joint space were performed in coronal and sagittal cuts of the temporomandibular joints, and the collected data were statistically analyzed by using the Mann-Whitney U test (α=.05). ResultsNo significant differences were found when the CR and MI positions and the presence or absence of TMD symptoms were compared in the younger and older groups. However, when the younger and older groups were compared, significant differences were found in all measures used in this study. ConclusionsThe condyle and mandibular fossa do not seem to be influenced by the CR or MI positions or by the presence or absence of TMD symptoms, but age seems to lead to a quantitative increase in the relationship between these structures.

Prevalence of temporomandibular disorders symptoms in patients with multiple sclerosis.

The aim of the present study was to assess the prevalence of symptoms of temporomandibular disorders (TMD) in patients with the relapsing-remitting form of multiple sclerosis (MS), the relationship between TMD and the severity of MS, and the presence of TMD symptoms in the evaluated groups. Sixty individuals were evaluated: 30 patients diagnosed with relapsing-remitting MS and 30 control individuals matched for gender and age range with no neurologic pathology. In order to investigate the TMD symptoms, the questionnaires of the EACD (European Academy of Craniomandibular Disorders) and the RDC/TMD (Research Diagnostic Criteria for Temporomandibular Disorders), both validated for TMD research, were administered. To assess the extent of disability produced by MS, the Expanded Disability Status Scale (EDSS) was used. The prevalence of TMD symptoms in patients with MS was 56.7% versus 16.7% for the control group, with a statistically significant difference between the groups (p=0.0016). No correlation was found between the severity of MS and the prevalence of TMD symptoms (Fisher's test, p=1.0).

The importance of complementary exams for the diagnosis of temporomandibular joint disorders

The importance of complementary exams for the diagnosis of temporomandibular joint disorders

Are headaches different from other chronic pains?

Dear Editor,Readingtheeditorial‘‘Timetoactonheadachedisorders’’[1]begs me as an oral physician [(medical and dentally trained,running an orofacial pain service, member of InternationalAssociation for the Study of Pain (IASP) and InternationalHeadache Society (IHS)] to ask a few questions.Why are headaches a separate entity from other chronicpain? What are the boundaries for the head? How do pro-fessionals look at them? How do patients interpret them? Theoral cavity and structures of the lower part of the face remainto a large extent the domain of the dental profession. Medicalstudents rarely have training in this field [2]. One needs onlyto compare the criteria for diagnosis of temporomandibulardisorders (TMD) in the classifications of IASP and IHS tothose of the TMD Research Diagnostic Criteria, to see vastdifferences [3]. Where do these disorders fit?The speciality of pain medicine is relatively young,IASP was founded in 1973 and IHS in 1981 with verysimilar aims but to include conditions of the head and neckonly. The former is truly multidisciplinary IHS is nearlyexclusively the domain of neurologists.The co-morbidities such as depression and anxiety arethe same for all chronic pain patients. TMD pain has beenshown through case control studies to be linked withmigraine, back pain, fibromyalgia and is an example ofcentral sensitisation [4]. Pain management, therefore, needsinput from a wide variety of specialties including anaes-thesia, neurology, rheumatology, neurosurgery, orthopae-dics, dentistry through to liaison psychiatry, physicaltherapy, psychology, occupational therapy. This need formultidisciplinary team (MDT) approach has resulted in painmanagement programs which have been shown throughsystematic reviews to be valuable. Yet in the headache fieldGaul et al. [5] state that acceptance for an MDT approach inheadache treatment is only now ‘‘gaining acceptance’’.IASP have declared this year the global year of head-ache in order to increase awareness of these conditions andthe two organisations have worked together to produce aseries of fact sheets for global use http://www.iasp-pain.org/Content/NavigationMenu/GlobalYearAgainstPain/GlobalYearAgainstHeadache. This would seem an excel-lent time to work towards unification to improve the globalburden of pain.

Perceived symptoms of psychological distress and salivary cortisol levels in young women with muscular or disk-related temporomandibular disorders

Objective. To assess any differences in psychological and endocrine variables between homogeneous core groups of young women with well-defined muscle- or disk-related temporomandibular disorders (TMDs) and matched controls. Material and methods. Fifteen women, aged 18–24 years, fulfilling the TMD Research Diagnostic Criteria I a/b (but not II or III) and 15 fulfilling the II a/b and III criteria were consecutively selected from referrals to an orofacial pain/TMD clinic. Thirty consecutive healthy age-matched women attending yearly routine check-ups at a general dental clinic served as controls. All 60 subjects answered a questionnaire, the Profile of Fatigue Related Symptoms (PFRS), and salivary samples on waking were collected for analysis of cortisol levels. Results. Symptom duration and pain levels were similar irrespective of muscle- or disk-related symptoms. Both diagnostic groups obtained scores that were similar and significantly higher than those of controls in all four scales of the PFRS: fatigue, emotional distress, cognitive difficulties and somatic symptoms. Salivary cortisol levels on waking did not differ between patients and controls. Conclusions. Patients with TMDs, irrespective of diagnosis, appeared to be more psychologically distressed than controls evaluated psychometrically, which is in line with earlier findings. A corresponding difference was not reflected in a single measurement of morning salivary cortisol. A more comprehensive evaluation of endocrine variables is probably necessary to reveal whether any differences actually exist in this respect.

Evidence-based versus experience-based views on occlusion and TMD

There is an old adage: never discuss divergent views concerning religion and politics with friends; you could lose a friend and create an enemy. Perhaps a variation on this notion applies to certain topics in dentistry and orthodontics. To this end, an acrimonious environment will surely ensue in the dental community when contending views are expressed about such topics as occlusion, temporomandibular disorders (TMDs), condyle position, gnathology, and mounted casts. Particularly sensitive to divergent thoughts on these topics are those who adhere to what is generally described as gnathology. Convinced of their “experience-based” views, they readily excuse away the contrary “evidence-based” (scientific) data. As Greene et al wrote, “Some clinicians are vocal critics of the TMD research community, arguing that clinicians’ anecdotal experiences are more valid than the contradictory research findings.” Even though the evidence points clearly toward occlusion having a secondary role in TMD, they still view occlusion as the primary and perhaps the single cause of TMD. This might be somewhat understandable if one agrees with Vig’s general view concerning some orthodontists: “orthodontists have lain greater emphasis on mastering their art than mastering their science. . . . There are many orthodontic controversies, past and present, that center on whose art is superior.” In a similar manner, Johnston argued: “Those who advocate new therapies seem disinclined to provide the evidence of efficacy (it may be bad for business), and the profession as a whole, perhaps being convinced in dental school of the irrelevance of ‘science,’ seems equally disinclined to demand it.” The experience-based and evidence-based views

On-line computerized diagnosis of pain-related disability and psychological status of TMD patients: a pilot study.

Temporomandibular disorders (TMD) is a collective term embracing a number of clinical problems, which involve the masticatory musculature, the temporomandibular joint or both. Virtually all theories dealing with the aetiology and treatment of TMD have recognized the importance of psychological factors. This paper reports the development of a computerized on-line program (NUS TMD v1.1) for the diagnosis of pain-related disability and psychological status of TMD patients based on Axis II of the research diagnostic criteria (RDC)/TMD (Dworkin, S.F. & LeResche, L. 1992. Journal of Craniomandibular Disorders: Facial Oral Pain, 6, 301), which was developed to redress the lack of diagnostic criteria in TMD research. Methods adopted by RDC/TMD for use in assessing Axis II status include a seven-item questionnaire for grading chronic pain severity, the Symptom Checklist 90 Revised (SCL-90-R) and a jaw disability checklist. A pilot study, based on 37 new TMD patient records, was conducted to study the pain-related disability and psychological status of TMD patients using this newly developed program. The mean age of the predominantly Chinese population (86.5%) was 32.19 years (range 20-72 years) with a sex distribution of 24 females and 13 males. Most patients (78%) had low disability, with 12 patients having low intensity and 17 patients having high intensity pain. Approximately 73% of the sample population were moderately or severely depressed. Patients that were moderately and severely depressed had significantly higher scores for limitation related to mandibular functioning than normal patients. The three most frequent jaw disabilities were: eating hard foods (84%), yawning (78%) and chewing (65%).