Calcitonin Gene-Related Peptide-Mediated Trigeminal Ganglionitis: The Biomolecular Link between Temporomandibular Disorders and Chronic Headaches.

A bidirectional causal relationship has been established between temporomandibular disorders (TMDs) and chronic headaches. Recent advances in the neurobiology of chronic pain offer a framework for understanding the comorbidity between these two conditions that might reside in the shared biomolecular mechanisms of peripheral and central sensitization. The initiation of these processes is inflammatory in nature and is most likely mediated by key molecules, including calcitonin gene-related peptide (CGRP). This scoping review proposes that CGRP-mediated neuroinflammation in the trigeminal ganglion may partly explain the biomolecular bidirectional link between TMDs and chronic headaches. Finally, clinical implications of this neuropathologic process are briefly discussed.

Acute and Chronic Temporomandibular Disorder Pain: A critical review of differentiating factors and predictors of acute to chronic pain transition.

AIMS: The aims of this critical review were to: (i) assess the factors that differentiate acute from chronic temporomandibular disorders (TMD) pain; (ii) assess the risk factors associated with the transition from acute to chronic TMD pain; and (iii) summarize and appraise the studies. METHOD: The databases used were MEDLINE, Embase, and Cochrane Database of Systematic Reviews. Eligible studies included articles comparing acute to chronic TMD pain, and cohort studies assessing the risk factors implicated in the transition from acute to chronic TMD pain. RESULTS: Seven articles were selected: one case-control study, three cross-sectional studies, and three cohort studies. These studies found that psychological factors were more common in chronic than acute TMD pain patients; however, these factors did not increase the transition risk in the multivariable model. Myofascial and baseline pain intensity were associated with the transition from acute to chronic TMD pain at a 6-month follow-up. Due to methodological weaknesses in the available literature, more research is required to establish the risk factors implicated in the transition from acute to chronic TMD pain. CONCLUSION: This review found some evidence that myofascial pain is associated with the transition risk from acute to chronic TMD pain at a 6-month follow-up and that pain intensity at baseline is associated with more intense TMD pain 6 months later. There is insufficient evidence to draw conclusions about the role of demographics and psychological disorders as independent risk factors.

Temporomandibular disorders: a human systems approach.

The face and associated cranial, oral and dental structures are among the most complicated areas of the body, contributing to an array of common orofacial disorders that include temporomandibular disorders (TMD), orofacial pain disorders and orofacial sleep disorders. This paper presents a broad, inclusive approach to diagnosis and management of TMD that reflects both conceptual models of human systems in understanding chronic illnesses as well as systematic reviews of treatment for successful management.

Prevalence and impact of signs and symptoms of temporomandibular disorders in dental students and faculty.

OBJECTIVES: Temporomandibular disorders (TMD) affect individuals undergoing increased stress, for example, dental professionals. No study to date has compared dental students and faculty in TMD manifestation. This cross-sectional study compared prevalence, risk factors, and impact on daily activities of self-reported TMD signs/symptoms between dental students and faculty at a predoctoral dental school, and between preclinical (first- to second-year) and clinical (third- to fourth-year) students. METHODS: A REDCap survey was sent to dental students and faculty, assessing TMD signs/symptoms (TMD Symptom Questionnaire), pain intensity (Chronic Graded Pain Scale), jaw function (Jaw Function Limitation Scale), parafunctions (Oral Behavioral Checklist), previous TMD treatments, anxiety/depression symptoms (Patient Health Questionnaire), perceived stress (Perceived Stress Scale), and sleep quality (RU-SATED Scale). Outcomes were compared between groups using chi-square and t-tests, adjusting for covariates with analyses of covariance (ANCOVA). RESULTS: Data derived from N = 145 participants (N = 108 students, N = 37 faculty). Dental students reported significantly higher prevalence (90.1% vs. 75.7%, p = 0.020) and greater number of TMD signs/symptoms (5.3 ± 3.5 vs. 3.0 ± 2.7, p < 0.001) compared to faculty. Students reported significantly more parafunctional activities (p = 0.000), jaw-strain episodes (prolonged mouth opening, p = 0.007), higher stress level (p = 0.008), and lower sleep quality (p = 0.002) than faculty. Difference in number of TMD signs/symptoms was maintained after adjusting for stress, sleep quality, and parafunctional/jaw-strain activities. Clinical students utilized significantly more often evidence-based TMD treatment compared to preclinical students. CONCLUSIONS: High prevalence of self-reported TMD was observed among dental students and faculty, with students reporting higher prevalence and impairment despite working in the same environment. Findings underscore the importance of education on preventive measures early in dental training to address contributing factors and TMD management.

Summaries of the Padua symposium on myofascial pain, fibromyalgia, and fascial pain disorders, June 2023, Aula Falloppio at the Human Anatomy Institute of the University of Padova, Italy.

The International Symposium on Myofascial Pain, Fibromyalgia, and Fascial Pain Disorders was held at the University of Padua, Padua, Italy in June of 2023. This report presents a summary of the presentations from scientists and clinicians from around the world who presented to the symposium. The purpose of this symposium and resultant paper is improve health professional's recognition and understanding of the clinical characteristics, co-morbidities, mechanisms, and treatment strategies for these common conditions to better understand and manage their pain, dysfunction, and quality life.

Diagnostic criteria for headache attributed to temporomandibular disorders.

AIMS: We assessed and compared the diagnostic accuracy of two sets of diagnostic criteria for headache secondary to temporomandibular disorders (TMD). METHODS: In 373 headache subjects with TMD, a TMD headache reference standard was defined as: self-reported temple headache, consensus diagnosis of painful TMD and replication of the temple headache using TMD-based provocation tests. Revised diagnostic criteria for Headache attributed to TMD were selected using the RPART (recursive partitioning and regression trees) procedure, and refined in half of the data set. Using the remaining half of the data, the diagnostic accuracy of the revised criteria was compared to that of the International Headache Society's International Classification of Headache Diseases (ICHD)-II criteria A to C for Headache or facial pain attributed to temporomandibular joint (TMJ) disorder. RESULTS: Relative to the TMD headache reference standard, ICHD-II criteria showed sensitivity of 84% and specificity of 33%. The revised criteria for Headache attributed to TMD had sensitivity of 89% with improved specificity of 87% (p < 0.001). These criteria are (1) temple area headache that is changed with jaw movement, function or parafunction and (2) provocation of that headache by temporalis muscle palpation or jaw movement. CONCLUSION: Having significantly better specificity than the ICHD-II criteria A to C, the revised criteria are recommended to diagnose headache secondary to TMD.

Management of painful temporomandibular disorders: Methods and overview of The National Dental Practice-Based Research Network prospective cohort study.

BACKGROUND: Patients often seek consultation with dentists for temporomandibular disorders (TMDs). The objectives of this article were to describe the methods of a large prospective cohort study of painful TMD management, practitioners' and patients' characteristics, and practitioners' initial treatment recommendations conducted by The National Dental Practice-Based Research Network (the "network"). METHODS: Participating dentists recruited into this study treated patients seeking treatment for painful TMDs. The authors developed self-report instruments based on well-accepted instruments. The authors collected demographics, biopsychosocial characteristics, TMD symptoms, diagnoses, treatments, treatment adherence, and painful TMDs and jaw function outcomes through 6 months. RESULTS: Participating dentists were predominately White (76.8%) and male (62.2%), had a mean age of 52 years, and were general practitioners (73.5%) with 23.8% having completed an orofacial pain residency. Of the 1,901 patients with painful TMDs recruited, the predominant demographics were White (84.3%) and female (83.3%). Patients' mean age was 44 years, 88.8% self-reported good to excellent health, and 85.9% had education beyond high school. Eighty-two percent had pain or stiffness of the jaw on awakening, and 40.3% had low-intensity pain. The most frequent diagnoses were myalgia (72.4%) and headache attributed to TMDs (51.0%). Self-care instruction (89.4%), intraoral appliances (75.4%), and medications (57.6%) were recommended frequently. CONCLUSIONS: The characteristics of this TMD cohort include those typical of US patients with painful TMDs. Network practitioners typically managed TMDs using conservative treatments. PRACTICAL IMPLICATIONS: This study provides credible data regarding painful TMDs and TMD management provided by network practitioners across the United States. Knowledge acquired of treatment recommendations and patient reports may support future research and improve dental school curricula.

Critical appraisal of methods used in randomized controlled trials of treatments for temporomandibular disorders.

AIMS: To evaluate the quality of methods used in randomized controlled trials (RCTs) of treatments for management of pain and dysfunction associated with temporomandibular muscle and joint disorders (TMJD) and to discuss the implications for future RCTs. METHODS: A systematic review was made of RCTs that were implemented from 1966 through March 2006, to evaluate six types of treatments for TMJD: orthopedic appliances, occlusal therapy, physical medicine modalities, pharmacologic therapy, cognitive-behavioral and psychological therapy, and temporomandibular joint surgery. A quality assessment of 210 published RCTs assessing the internal and external validity of these RCTs was conducted using the Consolidated Standards of Reporting Trials (CONSORT) criteria adapted to the methods of the studies. RESULTS: Independent assessments by raters demonstrated consistency with a mean intraclass correlation coefficient of 0.63 (95% confidence interval). The mean percent of criteria met was 58%, with only 10% of the RCTs meeting the four most important criteria. CONCLUSIONS: Much of the evidence base for TMJD treatments may be susceptible to systematic bias and most past studies should be interpreted with caution. However, a scatter plot of RCT quality versus year of publication shows improvement in RCT quality over time, suggesting that future studies may continue to improve methods that minimize bias.

Systematic review and meta-analysis of randomized controlled trials evaluating intraoral orthopedic appliances for temporomandibular disorders.

AIMS: To conduct a systematic review with meta-analysis of randomized controlled trials (RCTs) that have assessed the efficacy of intraoral orthopedic appliances to reduce pain in patients with temporomandibular disorders affecting muscle and joint (TMJD) compared to subjects receiving placebo control, no treatment, or other treatments. METHODS: A search strategy of MEDLINE, the Cochrane Library, the Cochrane CENTRAL Register, and manual search identified all English language publications of RCTs for intraoral appliance treatment of TMJD pain during the years of January 1966 to March 2006. Two additional studies from 2006 were added during the review process. Selection criteria included RCTs assessing the efficacy of hard and soft stabilization appliances, anterior positioning appliances, anterior bite appliances, and other appliance types for TMJD pain. Pain relief outcome measures were used in the meta-analyses, and the QUORUM criteria for data abstraction were used. A quality analysis of the methods of each RCT was conducted using the CONSORT criteria. The review findings were expressed both as a qualitative review and, where possible, as a mathematical synthesis using meta-analysis of results. RESULTS: A total of 47 publications citing 44 RCTs with 2,218 subjects were included. Ten RCTs were included in two meta-analyses. In the first meta-analysis of seven studies with 385 patients, a hard stabilization appliance was found to improve TMJD pain compared to non-occluding appliance. The overall odds ratio (OR) of 2.46 was statistically significant (P = .001), with a 95% confidence interval of 1.56 to 3.67. In the second meta-analysis of three studies including 216 patients, a hard stabilization appliance was found to improve TMJD pain compared to no-treatment controls. The overall OR of 2.15 was positive but not statistically significant, with a 95% confidence interval of 0.80 to 5.75. The quality (0 to 1) of the studies was moderate, with a mean of 55% of quality criteria being met, suggesting some susceptibility to systematic bias may have existed. CONCLUSION: Hard stabilization appliances, when adjusted properly, have good evidence of modest efficacy in the treatment of TMJD pain compared to non-occluding appliances and no treatment. Other types of appliances, including soft stabilization appliances, anterior positioning appliances, and anterior bite appliances, have some RCT evidence of efficacy in reducing TMJD pain. However, the potential for adverse events with these appliances is higher and suggests the need for close monitoring in their use.

Dental Decision Simulation (DDSim): Development of a virtual training environment.

PURPOSE: Case-based simulations are powerful training tools that can enhance learning and drive behavior change. This is an overview of the design/development of Dental Decision Simulation (DDSim), a web-based simulation of an electronic dental record (EDR). The purpose was to use DDSim to train dentists to make evidence-based treatment planning decisions consistent with current evidence. This simulated EDR provides case-based information in support of a set of defined evidence-based learning objectives. METHODS: The development of this complex simulation model required coordinated efforts to create several components: identify behavior changes, case authoring mechanism, create virtual patient visits, require users to make treatment plan decisions related to learning objectives, and a feedback mechanism to help users recognize departures from those learning objectives. This simulation was evaluated in a 2-arm, clinic-randomized, controlled pilot study examining the extent to which DDSim changed dentists' planned treatment to conform to evidence-based treatment guidelines relative to change in dentists not exposed to DDSim. Outcomes were measured by comparing preintervention and postintervention patient EDR treatment data. RESULTS: Changes in behavior over time did not favor intervention or control clinics. CONCLUSION: DDSim provides a standardized learning platform that cannot be achieved through the use of live patients. Both live patients and case-based simulations can be used to transfer knowledge and skill development. DDSim offers the advantage of providing a platform for developing treatment planning skills in a low-risk environment. However, further research examining behavior change is needed.

A quantitative evaluation of inflammatory cells in human temporomandibular joint tissues from patients with and without implants.

PURPOSE: Previous studies made only qualitative assessments of immune cell responses to temporomandibular joint (TMJ) implant wear debris. The aim of this study was to perform a quantitative comparison of inflammatory cell types in TMJ tissues with implant wear debris, TMJ tissues with a history of disc pathology without implant debris, and TMJ tissues from normal control subjects. MATERIALS AND METHODS: TMJ tissues were collected from the following 3 groups of subjects: 1) individuals with failed TMJ implants (implant group, n = 10), 2) patients with TMJ disc pathology but no history of implant placement (nonimplant surgery group, n = 10), and normal cadaveric tissues with no history of surgery (control group, n = 10). Tissue sections (5 microm) from all subjects were stained with hematoxylin-eosin, after which cell counts were done for 2 types of inflammatory cells: multinucleated giant cells and lymphocytes. Mean inflammatory cell counts from the 3 groups were compared by use of a 1-way analysis of variance procedure and Bonferroni adjustment to maintain an overall type I error rate of .05. RESULTS: Implant group tissues contained significantly more inflammatory cells than tissues from the nonimplant surgery and control groups (P < .0001). Multinucleated giant cells were only present in implant group tissues. Although the high number of multinucleated giant cells present in the implant group obscured a total count of lymphocytes for that group, lymphocyte cell counts were still significantly greater (P < .005) in implant group tissues than in tissues from the other 2 groups. CONCLUSIONS: Our data provide quantitative confirmation that the presence of Proplast-Teflon implant (Vitek, Houston, TX) wear debris is associated with a significant increase in the number of local multinucleated giant cells and lymphocytes.

Evaluation of surgically retrieved temporomandibular joint alloplastic implants: pilot study.

PURPOSE: The purpose of this study was to perform a retrieval analysis of temporomandibular joint (TMJ) alloplastic interpositional implants and test possible correlation between implant failure features and patient clinical outcomes. In addition, we investigated the implants' surface and examined the foreign body reaction associated with different types of alloplastic materials. MATERIALS AND METHODS: Twelve implants (Proplast/Teflon [Vitek, Houston, TX] and Silastic [Dow Corning, Midland, MI]) were surgically removed from the patients' TMJs. Implant surface failure features (fracture length, perforation of the implants) were observed using stereomicroscopy and recorded for description of the failure mechanisms and to statistically compare with clinical outcomes. Patients' clinical data (pain symptoms and mandibular function) were collected and examined. Clinical outcomes were obtained relative to symptom severity (Symptom Severity Index [SSI]) and jaw function (modified Mandibular Function Impairment Questionnaire [mMFIQ]). Peri-implant soft tissues and implants were analyzed with light microscopy and stereo zoom microscopy. Electron microprobe analysis of implant fragments and peri-implant tissues was performed. RESULTS: The statistical results showed that only the presence of implant perforation was statistically associated with the SSI, specifically with the pain tolerability dimension. No statistical association was seen between any of the other implant failure predictors and the SSI and between the predictors and the mMFIQ. Stereo zoom microscopy suggested that Proplast/Teflon implants (n = 7) were susceptible to perforation, layer tearing, fracture and fiber extrusion. The Silastic implants (n = 3) revealed a possible center perforation with fracture lines towards the periphery and fiber extrusion. Teflon implant wear debris particles appear to trigger a multinucleated giant cell foreign body reaction. CONCLUSION: Facial pain was a significant correlate to perforation and breakdown of the alloplastic TMJ interpositional implants, and most likely was the reason for implant removal.

Myogenous temporomandibular disorders: diagnostic and management considerations.

Myogenous temporomandibular disorders (or masticatory myalgia) are characterized by pain and dysfunction that arise from pathologic and functional processes in the masticatory muscles. There are several distinct muscle disorder subtypes in the masticatory system, including myofascial pain, myositis, muscle spasm, and muscle contracture. The major characteristics of masticatory myalgia include pain, muscle tenderness, limited range of motion, and other symptoms (eg, fatigability, stiffness, subjective weakness). Comorbid conditions and complicating factors also are common and are discussed. Management follows with stretching, posture, and relaxation exercises, physical therapy, reduction of contributing factors, and as necessary, muscle injections.

Development of a National TMJ Implant Registry and Repository-- NIDCR's TIRR.

PURPOSE: To provide a national systematic program to collect removed TMJ implants and biological tissues, make them available to researchers, and study them in conjunction with long-term clinical follow-up, with the ultimate goal of stimulating research toward understanding the safety and outcomes of TMJ implants. PROCESS: Two synchronized divisions: The Registry, recruiting clinicians and/or surgeons and patients, and collecting comprehensive clinical patient data over time; the Repository, procuring and archiving high quality, well characterized biological specimens and retrieved implants for dissemination. PARTICIPATION: Clinicians, surgeons, patients, researchers, pilot studies. PROGRESS: October 2002-present: Recruited 34 TMJ surgeons, 34 TMJ clinicians; registered 723 surgical/non-surgical TMJD patients and control subjects; collected 542 specimens, blood, saliva; initiated 19 projects using TIRR resources; produced 60 publications and presentations nationally and internationally; sent ten grants into review, with more being developed. PROSPECTS/PROJECTIONS: Continuing collection of long-term data for the development of new and improved implant designs and materials and investigation into understanding pathological mechanisms of TMJD.

Myofascial Pain: Mechanisms to Management.

More than 100 million adults in the United States have chronic pain conditions, costing more than $500 billion annually in medical care and lost productivity. They are the most common reason for seeking health care, for disability and addiction, and the highest driver of health care costs. Myofascial pain is the most common condition causing chronic pain and can be diagnosed through identifying clinical characteristics and muscle palpation. Management is focused on integrating patient training in changing lifestyle risk factors with evidence-based treatment. Understanding the cause, diagnosis, and management of myopain conditions will help prevent the impact of chronic pain.

Preventing Chronic Pain: A Human Systems Approach-Results From a Massive Open Online Course.

Chronic pain conditions are the top reason patients seek care, the most common reason for disability and addiction, and the biggest driver of healthcare costs; their treatment costs more than cancer, heart disease, dementia, and diabetes care. The personal impact in terms of suffering, disability, depression, suicide, and other problems is incalculable. There has been much effort to prevent many medical and dental conditions, but little effort has been directed toward preventing chronic pain. To address this deficit, a massive open online course (MOOC) was developed for students and healthcare professionals. "Preventing Chronic Pain: A Human Systems Approach" was offered by the University of Minnesota through the online platform Coursera. The first offering of this free open course was in the spring of 2014 and had 23 650 participants; 53% were patients or consumers interested in pain. This article describes the course concepts in preventing chronic pain, the analytic data from course participants, and postcourse evaluation forms.

Las afecciones de dolor crónico son el principal motivo de búsqueda de asistencia sanitaria, la causa más frecuente de discapacidad y toxicomanía, y el factor generador de costos sanitarios más importante, con un coste mayor al generado por el cáncer, la cardiopatía, la demencia y la diabetes. Las repercusiones en cuanto a sufrimiento, discapacidad, depresión, suicidio y otros problemas son incalculables. Se han consagrado grandes esfuerzos a la prevención de muchas enfermedades médicas y dentales, pero no se han dirigido los suficientes hacia la prevención del dolor crónico. Para hacer frente a este déficit, se ha desarrollado un curso en línea masivo y abierto (massive open online course, MOOC) para estudiantes y profesionales sanitarios. La Universidad de Minnesota ofreció el curso "Prevención del dolor crónico: enfoque de un sistema humanista" a través del sitio www.Coursera.org. La primera oferta de este curso abierto y gratuito se hizo en primavera de 2014 y acogió a 23 650 participantes; de los cuales un 53 % eran pacientes o clientes interesados en el dolor. En este artículo se describen los conceptos del curso en la prevención del dolor crónico, los datos analíticos de los participantes y los formularios de evaluación posteriores al curso.

Development of orofacial pain programs in dental schools.

This paper discusses the critical issues that surround the development of an orofacial pain program in a dental school and suggests strategies to address them. Since the University of Minnesota has an established orofacial pain program involved in both predoctoral and postdoctoral teaching, clinical and basic research, and interdisciplinary patient care over the past 20 years, this article uses this as a model for development of an orofacial pain program. The proposal includes overall goals, background and rationale, specific aims, and program activities, including teaching, research, patient care, and financial and resource needs. These features may be of assistance to those considering the development of such programs in the United States and elsewhere in the world.