The TMJ Association, Ltd.  (TMJA) is dedicated to providing TMJ patients, scientists and the general public with timely information on the latest scientific developments in the TMJ field.  We've assembled the following information in one place to help educate you as well as save you time and effort in your search for what's the latest in TMJ research. 

November 10, 2011 - Study Evaluates Risk Factors for Chronic Temporomandibular Joint and Muscle Disorders

Scientists affiliated with a large, seven-year study supported by the National Institute of Dental and Craniofacial Research (NIDCR), part of the National Institutes of Health, have published the preliminary results of the most comprehensive and systematic analysis to date of risk factors associated with chronic TMJD.  The findings are found in a special issue of the Journal of Pain, which now is available online to subscribers. 

These initial results from the Orofacial Pain:  Prospective Evaluation and Risk Assessment (OPPERA) study provide a voluminous body of high-quality data that confirms many previous discoveries and adds several new possibilities for risk.  These include:

• In women, the risk for chronic TMJD increases between the ages of 18 and 44, the age range evaluated in the study.  Previous studies have suggested that the risk was greatest during a woman’s early childbearing years and decreased thereafter.  In young men (ages 18-44), age was unrelated to TMJD incidence.
•     Chronic TMJD incidence does not correlate with low socio-economic status.  This finding is in stark contrast to trends seen in other chronic pain conditions.  Socio-economic status, for instance, has been shown to have a profound effect on musculoskeletal pain, sciatica, ulcer, and neuropathic pain.
•     Chronic TMJD seems to be associated with alterations in some parts of the nervous system that control pain perception.  Researchers found that TMJD patients, when compared to healthy study volunteers, were much more sensitive to a variety of stimuli that evoke mildly painful sensations.  They also show elevated heart rate responses at rest and during mild physical and psychological stress.
•     Genetic variability contributes to chronic TMJD.  Researchers found that chronic TMJD patients had alterations in several genes, including some known to influence stress response, psychological well-being, and inflammation.  These findings may help to explain the origins of TMJD and provide new targets for drugs to treat chronic pain.
•     Several clinical findings also were reported.   TMJD patients frequently experienced many more chronic pain conditions, such as lower back pain, headaches, and fibromyalgia.  Evidence of abnormal jaw function associated with teeth grinding and clenching was also observed.  Future investigations will attempt to unravel whether grinding and clenching is a cause of consequence of the condition.

November 2011 - Orofacial Pain Prospective Evaluation and Risk Assessment Study – The OPPERA Study

Temporomandibular disorders (TMD) consist of a heterogeneous family of musculoskeletal disorders that represent the most common chronic orofacial pain condition.

November 2011 - Potential Autonomic Risk Factors for Chronic TMD: Descriptive Data and Empirically Identified Domains from the OPPERA Case-Control Study

Several case-control studies have been conducted that examine the association between autonomic variables and persistent pain conditions; however, there is a surprising dearth of published studies in this area that have focused on temporomandibular disorders (TMD). The current study presents autonomic findings from the baseline case-control study of the OPPERA (Orofacial Pain: Prospective Evaluation and Risk Assessment) cooperative agreement. Measures of arterial blood pressure, heart rate, heart rate variability, and indirect measures of baroreflex sensitivity were assessed at rest and in response to a physical (orthostatic) and psychological (Stroop) stressors in 1,633 TMD-free controls and 185 TMD cases. In bivariate and demographically adjusted analyses, greater odds of TMD case status were associated with elevated heart rates, reduced heart rate variability, and reduced surrogate measures of baroreflex sensitivity across all experimental procedures. Principal component analysis was undertaken to identify latent constructs revealing 5 components. These findings provide evidence of associations between autonomic factors and TMD. Future prospective analyses in the OPPERA cohort will determine if the presence of these autonomic factors predicts increased risk for developing new onset TMD.

November 2011 - Summary of Findings from the OPPERA Baseline Case-Control Study: Implications and Future Directions

The articles in this compendium present first findings from the baseline case-control study of the OPPERA Program, a series of studies designed to identify risk factors for onset and persistence of painful Temporomandibular Disorders (TMD). This first series of manuscripts represents precursors to the ultimate goal of the OPPERA Program study, which is to build and then test a multivariable model designed to identify causal determinants of new onset TMD, as well as its chronicity.

November 2011 - Clinical Findings and Pain Symptoms as Potential Risk Factors for Chronic TMD: Descriptive Data and Empirically Identified Domains from the OPPERA Case-Control Study

Clinical findings from OPPERA’s baseline case-control study indicate significant differences between chronic TMD cases and controls with respect to trauma history, parafunction, other pain disorders, health status, and clinical examination data. Future analyses will examine their contribution to TMD onset.

November 2011 - Pain Sensitivity Risk Factors for Chronic TMD: Descriptive Data and Empirically Identified Domains from the OPPERA Case Control Study

This article describes experimental pain sensitivity differences between a large sample of people with chronic TMD and non-TMD controls, using multiple stimulus modalities and measures. Variability in the magnitude and consistency of case-control differences highlight the need to consider multiple testing measures to adequately assess pain processing alterations in chronic pain conditions.

November 2011 - Potential Genetic Risk Factors for Chronic TMD: Genetic Associations from the OPPERA Case Control Study

Genetic risk factors for TMD pain were explored in the case-control component of the OPPERA cooperative agreement, a large population-based prospective cohort study. Over 350 candidate pain genes were assessed using a candidate gene panel, with several genes displaying preliminary evidence for association with TMD status.

November 2011 - Potential Psychosocial Risk Factors for Chronic TMD: Descriptive Data and Empirically Identified Domains from the OPPERA Case-Control Study

This article reports baseline psychosocial findings from the OPPERA Study, a large prospective cohort study designed to discover causal determinants of TMD pain. Findings indicate significant differences between TMD cases and TMD-free controls across multiple psychosocial constructs, and future analyses will determine whether these psychosocial factors increase risk for new onset TMD.

November 2011 - The OPPERA Study: Act One

Some perspectives are offered below to the diverse community of readers of this special issue of The Journal of Pain, regarding findings from a long-awaited large-scale study of Temporomandibular muscle and joint disorders (TMD or TMDs). TMDs are, by far, the most prevalent of all chronic orofacial pain conditions. They comprise a cluster of related chronic pain conditions that affect the hard and soft structures of the orofacial region, characterized principally by: 1) the presence of pain typically in the pre-auricular area in front of the ear, the cheeks and/or temporal area; 2) limitations in movement of the mandible; and 3) joint sounds detected in the temporomandibular joint (TMJ) during functional excursions of the jaw.

November 2011 - Study Methods, Recruitment, Sociodemographic Findings, and Demographic Representativeness in the OPPERA Study

Demographic associations with TMD were consistent with population benchmarks and with other studies, suggesting broad applicability of these OPPERA findings. Greater occurrence of TMD in non-Hispanic-Whites than in other racial/ethnic groups and the lack of a socioeconomic gradient contradicts the disparities seen in many other health conditions.

October 28, 2011 - Excess Risk of Temporomandibular Disorder Associated With Cigarette Smoking in Young Adults

This study showed that smoking was associated with TMD risk in females, but only in young adulthood. It replicated this finding in 2 nationally representative surveys of females in the US and Australia. Findings may alert clinicians to recognize that smoking is a concern for TMD in younger female patients.

October 14, 2011 - No effect of glucosamine sulfate on osteoarthritis in the temporomandibular joints-a randomized, controlled, short-term study

Oral glucosamine sulfate was not superior to placebo in reducing signs and symptoms of osteoarthritis in the TMJs in this short-term trial.

October 7, 2011 - Increased Risk of Temporomandibular Joint Closed Lock: A Case-Control Study of ANKH Polymorphisms

Fibrous ankylosis was identified in the TMJ of ank mutant mice. In the human sample, ANKH-OR polymorphism was found to be a genetic marker associated with TMJ closed lock. Future investigations correlating genetic polymorphism to TMD are indicated.

October, 2011 - Temporomandibular Joint Arthritis in Pediatric Sjögren Disease and Sarcoidosis

There are other rheumatologic diseases that can also present with TMJ inflammation [e.g., sarcoidosis, Sjögren disease, mixed connective tissue disease (MCTD)]^4,5​,6, but the prevalence is less known.

September 23, 2011 - Estrogen in cycling rats alters gene expression in the temporomandibular joint, trigeminal ganglia and trigeminal subnucleus caudalis/upper cervical cord junction

Females report temporomandibular joint (TMJ) pain more than men and studies suggest estrogen modulates this pain response. Our goal in this study was to determine genes that are modulated by physiological levels of 17β-estradiol that could have a role in TMJ pain. To complete this goal, saline or complete Freund's adjuvant was injected in the TMJ when plasma 17β-estradiol was low or when it was at a high proestrus level. TMJ, trigeminal ganglion, and trigeminal subnucleus caudalis/upper cervical cord junction (Vc/C_1–2) tissues were isolated from the treated rats and expression of 184 genes was quantitated in each tissue using real-time PCR. Significant changes in the amount of specific transcripts were observed in the TMJ tissues, trigeminal ganglia, and Vc/C_1–2 region when comparing rats with high and low estrogen. GABA A receptor subunit α6 (Gabra6) and the glycine receptor α2 (Glra2) were two genes of interest because of their direct function in neuronal activity and a >29-fold increase in the trigeminal ganglia was observed in proestrus rats with TMJ inflammation. Immunohistochemical studies showed that Gabrα6 and Glrα2 neuronal and not glial expression increased when comparing rats with high and low estrogen. Estrogen receptors α and β are present in neurons of the trigeminal ganglia, whereby 17β-estradiol can alter expression of Gabrα6 and Glrα2. Also, estrogen receptor α (ERα) but not ERβ was observed in satellite glial cells of the trigeminal ganglia. These results demonstrate that genes associated with neurogenic inflammation or neuronal excitability were altered by changes in the concentration of 17β-estradiol. J. Cell. Physiol. 226: 3169–3180, 2011.

September 19, 2011 - Altered Functional Connectivity Between the Insula and the Cingulate Cortex in Patients With Temporomandibular Disorder: A Pilot Study

As a main finding, functional connectivity analyses revealed an increased functional connectivity between the left anterior IC and pregenual anterior cingulate cortex (ACC) in TMD patients, during both resting state and applied pressure pain. Within the patient group, there was a negative correlation between the anterior IC-ACC connectivity and clinical pain intensity as measured by a visual analog scale. Conclusions.- Since the pregenual region of the ACC is critically involved in antinociception, we hypothesize that an increase in anterior IC-ACC connectivity is indicative of an adaptation of the pain modulatory system early in the chronification process.

September, 2011 - Temporomandibular disorders are differentially associated with headache diagnoses: a controlled study

TMD, TMD subtypes, and TMD severity are independently associated with specific headache syndromes and with headache frequency. This differential association suggests that the presence of central facilitation of nociceptive inputs may be of importance, as positive association was observed only when muscular TMD pain was involved.

August 14, 2011 - Influence of the method of TM joint total replacement implantation on the loading of the joint on the opposite side

The temporomandibular (TM) joint is one of the most used joints in the human body, and any defect in this joint has a significant influence on quality of life. The objective of this study was to create a parametric numerical finite element (FE) analysis to compare the effect of surgical techniques used for total TM joint replacement implantation on loading the TM joint on the other side. Our hypothesis is that for the optimal function of all total TM joint replacements used in clinical practice it is crucial to devise a minimally invasive surgical technique, whereby there is minimum resection of masticatory muscles. This factor is more important than the design of the usually used total TM joint replacements. The extent of muscle resection influences the mechanical loading of the whole system. In the parametric FE analyses, the magnitude of the TM joint loading was compared for four different ranges of muscle resections during bite, using an anatomical model. The results obtained from all FE analyses support our hypothesis that an increasing extent of the muscle resection increased the magnitude of the TM joint overloading on the opposite side. The magnitude of the TM joint overloading increased depending on the muscle resection to 235% for bite on an incisor and up to 491% for bite on molars. Our study leads to a recommendation that muscle resection be minimised during replacement implantation and to a proposal that the attachment of the condylar part of the TM joint replacement be modified.

August 9, 2011 - The effectiveness of cognitive-behavioural therapy for temporomandibular disorders: a systematic review

Summary Cognitive-behavioural therapy (CBT) and its effects on temporomandibular disorders (TMD) have been examined in several studies. We are trying to combine results of these studies and to explore the effectiveness. MEDLINE, EMBASE, Cochrane Central Register of Controlled Trial, Pubmed and the Chinese Biomedical Literature Data were searched to collect randomised and semi-randomised controlled trials (RCTs), comparing CBT with any control group receiving other dental treatments. Two authors independently retrieved, extracted and assessed the quality of included studies. The search strategy resulted in 323 studies, of which five met the inclusion criteria, including three RCTs and two semi-RCTs. The quality of the included studies was diverse. Meta-analysis was not performed owing to five studies involving different comparison groups and follow-up periods. The effect of CBT on patients with TMD is inconsistent among the studies, so no firm conclusion could be drawn in this systematic review. There is insufficient evidence to make firm recommendations for the use of CBT over other intervention for the treatment of TMD. Further high-quality RCTs are clearly needed for this theme.

August 6, 2011 - Animal Models of Temporomandibular Joint Disorders: Implications for Tissue Engineering Approaches

Animal models for temporomandibular joint disorder (TMD) or degradation are necessary for assessing the value of current and future tissue engineering therapies. After reviewing the literature, it is quite apparent that most TMD animal studies can be categorized into chemical approaches or surgical/mechanical approaches. Overall, it was found that the top five cited manuscripts for all chemical models were cited by almost 40% more manuscripts than the top five manuscripts for surgical/mechanical models. It is clear that the chemical approaches have focused on the inflammatory aspect of TMDs and its relationship to pain. However, chemical irritants must be tested in larger animal models, and the effect of short-term inflammation on the mechanical properties of the fibrocartilage must be examined. Nevertheless, therapeutic approaches aimed at reducing or controlling inflammation could use the established chemical methods. Surgical/mechanical methods can be used as negative controls for first generation TMJ tissue engineering approaches when the therapy is applied immediately after injury. Next generation tissue engineering approaches will require testing on tissues degenerated for a few months after the surgical/mechanical methods, with enhanced functional assessment techniques.

July 7, 2011 - Effect of gonadal steroid hormones on formalin-induced temporomandibular joint inflammation

We have recently demonstrated that gonadal steroid hormones decrease formalin-induced temporomandibular joint nociception in rats. Given that the attenuation of inflammation is a potential mechanism underlying this antinociceptive effect, we evaluated the effect of gonadal steroid hormones on formalin-induced temporomandibular joint inflammation. Plasma extravasation, a major sign of acute inflammation, and neutrophil migration, an important event related to tissue injury, were evaluated. Formalin induced significantly lower temporomandibular joint plasma extravasation and neutrophil migration in proestrus females than in males and in diestrus females. Since estradiol serum level is high in proestrus females and low in diestrus females and in males, these findings suggest that the high physiological level of estradiol decreases temporomandibular joint inflammation. Estradiol but not progesterone administration in ovariectomized females significantly decreased formalin-induced plasma extravasation and neutrophil migration, an effect that was blocked by the estrogen receptor antagonist ICI 182780. Plasma extravasation and neutrophil migration were not affected by orchiectomy, but testosterone or estradiol administration in orchidectomized males significantly decreased them. The androgen receptor antagonist flutamide blocked the anti-inflammatory effect of testosterone while ICI 182780 blocked that of estradiol in males. Previous intravenous administration of a nonspecific selectin inhibitor significantly decreased formalin-induced temporomandibular joint nociception and neutrophil migration in males, revealing a potent and positive correlation between temporomandibular joint nociception and inflammation. Taken together, these findings demonstrate a pronounced anti-inflammatory effect of estradiol and testosterone in the temporomandibular joint region and suggest that this effect may mediate, at least in part, the antinociceptive effect of these hormones.

July 2011 - Temporomandibular joint and normal occlusion: Is there anything singular about it? A computed tomographic evaluation

No singular characteristic in the temporomandibular joints of the normal occlusion group was verified. The largest mediolateral diameter of the mandibular condylar processes and the posterior joint spaces showed statistically significant differences between the right and left sides. Evaluation of the position of the condyles in their respective mandibular fossae showed noncentralized positioning for the right and left sides.

July 2011 - 17β-estradiol aggravates temporomandibular joint inflammation through the NF-κB pathway in ovariectomized rats

These results suggest that estradiol aggravates TMJ inflammation through the NF-κB pathway, leading to the induction of proinflammatory cytokines.

June 23, 2011 - Are Ulcerative and Nonulcerative Interstitial Cystitis/Painful Bladder Syndrome 2 Distinct Diseases? A Study of Coexisting Conditions

When N-ULC and ULC IC/PBS patients were compared, more N-ULC IC/PBS patients had fibromyalgia (P = .03), migraines (P = .03), temporomandibular joint disorder (P < .01), and higher CES-D (P = .02) and SIS scores (P = .01).  Notable differences in the number of comorbid diagnoses and symptoms were seen between IC/PBS subtypes and controls," the authors write.

June 21, 2011 - Implant-supported mandibular splinting affects temporomandibular joint biomechanics

During jaw opening-closing, splinting of the mandible leads to a significant reduction of mandibular deformation and intercondylar distance and to altered stress-field paths, resulting in changed loading patterns of the TMJ structures

June 16, 2011 - Evaluation of the Mechanism and Principles of Management of Temporomandibular joint dislocation. Systematic review of literature and a proposed new classification of Temporomandibular joint dislocation

The more complex and invasive method of treatment may not necessarily offer the best option and outcome of treatment, therefore conservative approaches should be exhausted and utilized appropriately before adopting the more invasive surgical techniques.

June 13, 2011 - Association of clinical findings of temporomandibular disorders (TMD) with self-reported musculoskeletal pains

TMD findings associate with pain in several locations. Female gender and presence of impaired health were particularly related to occurrence of multiple pain conditions.

June 9, 2011 - Causes of Persistent Joint Pain After Arthrocentesis of Temporomandibular Joint

Persistent joint pain after arthrocentesis is generally associated with extensive amounts of joint effusion or erosive cortical changes of the condyle.

June 6, 2011 -Estrogen receptors localization in the spinal trigeminal nucleus: An immunohistochemical study in humans

There is increasing evidence for estrogenic modulation of neurotransmission within the trigeminal pain pathway. It is also likely that the effects of estrogens may be influenced by the presence and localization of estrogen receptors (ERs) in a given brain area. To date, human data on the localization of ERs in the spinal trigeminal nucleus (STN), a key brain region in craniofacial nociception, are lacking.

To ascertain whether ERs are expressed in the human STN, we performed immunohistochemical analysis on medulla oblongata samples taken from eight adult subjects (three men and five women; age range, 23–71years) who had died from causes unrelated to neurologic or endocrine diseases. Paraffin-embedded sections at the level of the subnucleus caudalis and interpolaris were incubated with anti-estrogen receptor alpha (ERα) and anti-estrogen receptor beta (ERβ) antibodies. ERα immunoreactivity was detected in the nucleus and cytoplasm of neuronal and glial cells in the STN and in the nerve fibers within the spinal trigeminal tract in all eight subjects; ERβ immunoreactivity was observed in the cytoplasm of neuronal cells in five subjects. This study is the first to provide evidence in humans that ER immunoreactivity is detectable on neuronal and glial cells of the STN. The two ER subtypes exhibited different expression patterns, with higher expression levels of ERα than ERβ. The presence of ER-containing cells in the STN suggests that estrogens may directly affect trigeminal neuron excitability in humans.

June 3, 2011 - Orthodontics for treating temporomandibular joint (TMJ) disorders

There is no evidence about the effects of different types of orthodontic braces for problems associated with the joint between the lower jaw and skull. When the joint between the lower jaw and the base of the skull is not working well (temporomandibular disorders (TMD)), it can lead to abnormal jaw movement or locking, noises (clicking or grating), muscle spasms, tenderness or pain. TMD is very common, and it is believed by some that it may be caused by the occlusion (the way the teeth bite), trauma or psychological stress. There is also a belief that the pain associated with TMD is similar, in that respect, to low back pain and may be related to variations of a person's individual pain perception. Changes in the way the teeth meet can be produced by the use of active orthodontic appliances. This review found that there is no evidence from trials to show that active orthodontic treatment can prevent or relieve temporomandibular disorders adding support to teeth not being part of its cause. It is suspected that we do not know the real cause of TMD at present.

June 2011 - Sex-related differences in animal models of migraine headache

Trigeminal nerve-mediated pain disorders such as migraine, temporomandibular joint disorder, and classical trigeminal neuralgia are more prevalent in women than in men. Female laboratory animals also show greater responses to various nociceptive stimuli than male animals. However, current knowledge of migraine pathogenesis is based primarily on experimental studies conducted in male animals and lack of migraine research with female animals limits clinical relevance. Migraine is triggered by any alteration in the intrinsic or extrinsic milieu and women at reproductive age are continuously prone to waxing and waning effects of female sex hormones. The experimental approach to this problem is complex because the rodent estrous cycle differs from the human cycle, and because exogenous hormone replacement in ovariectomized females has its limitations. The existence of multiple estrogen receptors in the trigeminal system also presents a challenge. Estrogens do not seem to directly affect calcitonin gene-related peptide or 5-HT(1D) receptors in the trigeminal system. Nonetheless, 2 estrogen receptors activate MAPK/ERK signaling pathway that mediates nociceptive processing in trigeminal nucleus caudalis. In addition, estrogen enhances susceptibility to cortical spreading depression, the neurobiological event underlying migraine aura, which may be independent of the estrous cycle. Further studies in female animals are required to clarify mechanisms underlying sex differences with respect to fluctuating sex hormones, cortical spreading depression, and excitability of the trigeminovascular system.

June 2011 - Mechanisms of pain modulation by sex hormones in migraine

A number of pain conditions, acute as well as chronic, are much more prevalent in women, such as temporomandibular disorder (TMD), irritable bowel syndrome, fibromyalgia, and migraine. The association of female sex steroids with these nociceptive conditions is well known, but the mechanisms of their effects on pain signaling are yet to be deciphered. We reviewed the mechanisms through which female sex steroids might influence the trigeminal nociceptive pathways with a focus on migraine. Sex steroid receptors are located in trigeminal circuits, providing the molecular substrate for direct effects. In addition to classical genomic effects, sex steroids exert rapid nongenomic actions to modulate nociceptive signaling. Although there are only a handful of studies that have directly addressed the effect of sex hormones in animal models of migraine, the putative mechanisms can be extrapolated from observations in animal models of other trigeminal pain disorders, like TMD. Sex hormones may regulate sensitization of trigeminal neurons by modulating expression of nociceptive mediator such as calcitonin gene-related peptide. Its expression is mostly positively regulated by estrogen, although a few studies also report an inverse relationship. Serotonin (5-Hydroxytryptamine [5-HT]) is a neurotransmitter implicated in migraine; its synthesis is enhanced in most parts of brain by estrogen, which increases expression of the rate-limiting enzyme tryptophan hydroxylase and decreases expression of the serotonin re-uptake transporter. Downstream signaling, including extracellular signal-regulated kinase activation, calcium-dependent mechanisms, and cAMP response element-binding activation, are thought to be the major signaling events affected by sex hormones. These findings need to be confirmed in migraine-specific animal models that may also provide clues to additional ion channels, neuropeptides, and intracellular signaling cascades that contribute to the increased prevalence of migraine in women.

June 2011 - A critical review of interpositional grafts following temporomandibular joint discectomy with an overview of the dermis-fat graft

The aim of this critical review is to determine what constitutes an ideal disc replacement material and whether any of the existing materials reported in the literature satisfy the requirements of an effective disc substitute following temporomandibular joint (TMJ) discectomy. Over the last half century a myriad of interpositional materials have been used in the TMJ but nearly all have been less than successful. The disasters that followed the early use of alloplastic interpositional implants in the 1980s prompted the increased use of autogenous grafts in the 1990s. Whilst studies by the author on the use of dermis-fat grafts have been largely positive, there are still concerns that make the dermis-fat graft a less than ideal interpositional material for use in discectomized joint cavities. In reviewing the literature, it is clear that there is still no ideal interpositional material that satisfies all the criteria for replacement of a missing articular disc following TMJ discectomy.

May 26, 2011 - Genetic polymorphisms in folate pathway enzymes, DRD4 and GSTM1 are related to temporomandibular disorder

Some genetic polymorphisms related to folates metabolism, inflammatory oxidative stress, and neurotransmission responses to pain, has been significantly associated to TMD syndrome.

May 21, 2011 - Use of opioids in long-term management of temporomandibular joint dysfunction

The long-term treatment of patients with chronic temporomandibular joint dysfunction has been challenging. The long-term use of opioids in these patients can be neither supported nor refuted based on current evidence. However, evidence is available to support the long-term use of opioids in other chronic noncancer pain states with reduced pain, improved function, and improved quality of life. One group of patients with chronic temporomandibular joint pain, for whom both noninvasive and invasive treatment has failed, might benefit from long-term opioid medication. The choices include morphine, fentanyl, oxycodone, tramadol, hydrocodone, and methadone. Adjunct medication, including antidepressant and anticonvulsant drugs, can also be used. The safety of these medications has been well established, but the potential for adverse drug-related behavior does exist, requiring appropriate patient selection, adequate monitoring, and intervention when needed.

May 11, 2011 - Arthroscopy for temporomandibular disorders

Temporomandibular disorder (TMD) is a term describing problems with the chewing muscles or the jaw joint and associated structures, or both. There are different types of treatments for TMDs. Arthroscopy (a form of surgery) has been used to reduce signs and symptoms of patients with TMD, but the effectiveness has still not been totally explained. This review found no differences after treatment in mandibular functionality or in clinical evaluations. Arthroscopy led to greater improvement in maximum interincisal opening after 12 months than arthrocentesis. When compared with arthroscopy, open surgery was more effective at reducing pain after 12 months.

May 11, 2011 - Adolescents with Temporomandibular Disorder Pain-The Living with TMD Pain Phenomenon

TMD pain is a substantial problem for affected adolescents and has consequences for all aspects of their lives. In this study, the adolescents were able to talk openly and introduce issues outside of the interview protocol. Qualitative analysis deepens our understanding of the adolescent patient with TMD pain

May 10, 2011 - Acupuncture for treating temporomandibular joint disorders: A systematic review and meta-analysis of randomized, sham-controlled trials

This systematic review and meta–analysis demonstrate that the evidence for acupuncture as a symptomatic treatment of temporomandibular joint disorder (TMD) is limited.

May 4, 2011 - Genomics and the new perspectives for temporomandibular disorders

The field of temporomandibular disorders (TMD) is experiencing significant changes in terms of aetiology and treatment. Researchers and clinicians are becoming increasingly aware of the possibility that genetic variations may play a role in pain perception and onset of TMD. In this review, we purpose to briefly describe these allelic variants, how they may be involved in TMD pathophysiology and how they may affect TMD treatment. Studies have already pointed the association between TMD and genetic polymorphisms in the oestrogen receptor alpha, adrenergic receptor beta 2, serotonin receptor, serotonin transporter and catechol-O-methyltransferase genes, and other candidate genes continue to emerge. The main implication of these findings refers to the promising possibilities of “genome/omics-based personalised care”, which consists of tailoring individual treatment based on personalised medication, depending on the individual genetic differences and early diagnosis and prognosis of the disorder, preventing acute pain conditions from becoming chronic. The following years of research shall focus on collecting and endorsing these findings if we are to provide patients in pain with efficient and successful TMD treatments.

May 2, 2011 - Resiliency Of Temporomandibular Joint Disc-A Literature Review

A sound understanding of biomechanical behavior of TMJ (Temporomandibular Joint) disc is necessary for evaluation and treatment of various temporomandibular joint disorders.

April 25, 2011 - Efficacy of botulinum toxin type A for treatment of persistent myofascial TMD pain: a randomized, controlled, double-blind multicenter study

The investigators concluded that there was a strong placebo effect, which means that less well-controlled studies may not be valid. While there was a slightly better outcome for Botox than for saline, it was small and was not experienced by all patients.  The authors recommended against the use of Botox as an adjunct to conservative treatment of persistent myofascial pain on the basis of its high cost and lack of efficacy. 

April 15, 2011 - Effect of Hypnosis on Pain and Blink Reflexes in Patients With Painful Temporomandibular Disorders

Hypnosis thus seems to reduce complex temporomandibular disorder pain, most likely because of cortical changes with little, if any, involvement of brainstem reflex pathways.

April 9, 2011 -Further Validation of a Model of Fibromyalgia Syndrome in the Rat

We have recently developed an animal model of fibromyalgia syndrome in the rat. In this model, rats exposed to unpredictable sound stress develop a delayed onset enhancement and prolongation of cytokine-induced mechanical hyperalgesia in muscle and skin. In this study, we tested the hypothesis that our model also manifests symptoms of common comorbid diagnoses: irritable bowel syndrome, temporomandibular disorder, and anxiety. Both visceral sensitivity and cytokine hyperalgesia in masseter muscle were present in the stressed rats. Furthermore, in an established model of irritable bowel syndrome-water avoidance-we observed significant muscle hyperalgesia. Finally, using the elevated plus maze to assess for anxiety level, we observed a significantly higher anxiety level in sound stress-exposed rats. Thus, unpredictable sound stress produces a condition in the rat with several features-delayed onset visceral and temporomandibular hyperalgesia and increased anxiety, as well as cutaneous and muscle hyperalgesia-commonly found in patients with fibromyalgia syndrome. PERSPECTIVE: A stress model-unpredictable sound-in the rat exhibits several features (cutaneous, musculoskeletal, and visceral hyperalgesia, as well as anxiety) that are found in patients with fibromyalgia syndrome. Thus, this model may be used to test hypotheses about the underlying mechanisms and response to therapy in patients with fibromyalgia.

April 4, 2011 - Researchers mimic body's own healing potential to create personalised therapies for inflammation

Scientists at Barts and The London School of Medicine and Dentistry and Harvard Medical School, Boston have found a way of mimicking the body's natural mechanism of fighting inflammation. During inflammation cells release very small particles termed 'microparticles' that retain features of their parent cell. The scientists discovered that certain microparticles were beneficial to health, and that these microparticles contained anti-inflammatory lipids, which help terminate inflammation and return the body to its normal balance.

The discovery, featured online in the current edition of the Journal of Immunology, paves the way for new personalized treatments to target uncontrolled inflammation that need not rely on synthetic biomaterials, therefore reducing potential toxicity.

Inflammation of joints and muscles is implicated in many human diseases including cardiovascular disease, arthritis and temporomandibular disorders and its treatment remains an unmet medical need.

April 1, 2011 -

Temporomandibular joint involvement in rheumatoid arthritis, systemic lupus erythematosus and systemic sclerosis

The aim of the present study was to estimate the prevalence of temporomandibular joint (TMJ) symptoms and clinical findings in Albanian patients with rheumatoid arthritis, systemic lupus erythematosus and systemic sclerosis. The authors examined 124 consecutive hospitalized patients (88 with rheumatoid arthritis, 22 with systemic lupus erythematosus and 14 with systemic sclerosis) and 124 age- and gender-matched healthy controls using a questionnaire and an oro-facial clinical examination for assessing the presence of TMJ sounds, pain in the TMJ area, tenderness of masticatory muscles and limited mouth opening. Significantly more patients (67%) reported TMJ symptoms than controls (19%). A significantly higher proportion of patients (65%) exhibited clinical signs of temporomandibular dysfunction compared with controls (26%). The most frequent findings in rheumatoid arthritis were temporomandibular sounds and pain. Pain was found in a significantly higher proportion in patients with systemic lupus erythematosus compared with controls. Difficulty and limitation in mouth opening were observed in the majority of systemic sclerosis patients, and in only a minority of rheumatoid arthritis patients. This study supports the notion that TMJ examination should be encouraged in the rheumatology setting and clinicians should be able to provide pain management and patient support.

April 2011 - Psychophysiological responses to pain stimulation and cognitive tasks in female temporomandibular disorder patients

The low EMG responses in the TMD group may be taken in support of the Pain Adaptation Model of musculoskeletal pain, in which reduced muscular activity serves to protect a painful area. However, it may also be supportive of the Integrated Pain Adaptation Model, where higher central nervous structures influence local muscular output. The group similarities in systemic physiological responding in combination with the elevated levels of negative state affect in the TMD patients confirm previous reports of psychosocial differences being more reliable indicators of TMD than generalized physiological responding.

April 2011 - A pain in the neck? Which regions of body pain are most associated with pain interference and other health outcomes 6 weeks after motor vehicle collision

April 2011 - Widespread palpation tenderness is associated with multiple pain conditions in females with temporomandibular disorders

March 19, 2011 - Botox's Effect on the Jaw Joint

Botox in the masseter caused an osteoporotic condition in the TMJ of rabbits, raising some concern that this treatment might not be healthy for the joint in the long term.

March 15, 2011 - Central Sensitization: Implications for Diagnosis and Treatmetn of Pain

Nociceptor inputs can trigger a prolonged but reversible increase in the excitability and synaptic efficacy of neurons in central nociceptive pathways, the phenomenon of central sensitization. Central sensitization manifests as pain hypersensitivity, particularly dynamic tactile allodynia, secondary punctate or pressure hyperalgesia, aftersensations, and enhanced temporal summation. It can be readily and rapidly elicited in human volunteers by diverse experimental noxious conditioning stimuli to skin, muscles or viscera, and in addition to producing pain hypersensitivity, results in secondary changes in brain activity that can be detected by electrophysiological or imaging techniques. Studies in clinical cohorts reveal changes in pain sensitivity that have been interpreted as revealing an important contribution of central sensitization to the pain phenotype in patients with fibromyalgia, osteoarthritis, musculoskeletal disorders with generalized pain hypersensitivity, headache, temporomandibular joint disorders, dental pain, neuropathic pain, visceral pain hypersensitivity disorders and post-surgical pain. The comorbidity of those pain hypersensitivity syndromes that present in the absence of inflammation or a neural lesion, their similar pattern of clinical presentation and response to centrally acting analgesics, may reflect a commonality of central sensitization to their pathophysiology. An important question that still needs to be determined is whether there are individuals with a higher inherited propensity for developing central sensitization than others, and if so, whether this conveys an increased risk in both developing conditions with pain hypersensitivity, and their chronification. Diagnostic criteria to establish the presence of central sensitization in patients will greatly assist the phenotyping of patients for choosing treatments that produce analgesia by normalizing hyperexcitable central neural activity. We have certainly come a long way since the first discovery of activity-dependent synaptic plasticity in the spinal cord and the revelation that it occurs and produces pain hypersensitivity in patients. Nevertheless, discovering the genetic and environmental contributors to and objective biomarkers of central sensitization will be highly beneficial, as will additional treatment options to prevent or reduce this prevalent and promiscuous form of pain plasticity.

March 2011 - Central Sensitivity Syndromes: Mounting Pathophysiologic Evidence to Link Fibromyalgia with Other Common Chronic Pain Disorders

This paper presents a review of relevant articles with a specific goal of identifying pathophysiologic findings related to nociceptive processing. The extant literature presents considerable overlap in the pathophysiology of these diagnoses. Given the psychosomatic lens through which many of these disorders are viewed, demonstration of evidence-based links supporting shared pathophysiology between these disorders could provide direction to clinicians and researchers working to treat these diagnoses. “Central sensitivity syndromes” denotes an emerging nomenclature that could be embraced by researchers investigating each of these disorders. Moreover, a shared paradigm would be useful in promoting cross-fertilization between researchers. Scientists and clinicians could most effectively forward the understanding and treatment of fibromyalgia and other common chronic pain disorders through an appreciation of their shared pathophysiology.

February 28, 2011 -

Temporomandibular Disorders are Differentially Associated With Headache Diagnoses: A Controlled Study

TMD, TMD subtypes, and TMD severity are independently associated with specific headache syndromes and with headache frequency. This differential association suggests that the presence of central facilitation of nociceptive inputs may be of importance, as positive association was observed only when muscular TMD pain was involved.

February 25, 2011 - Lubricin immunohistochemical expression in human TMJ disc with internal derangement

Lubricin is a chondroprotective, mucinous glycoprotein which contribute to joint lubrication, especially to boundary lubrication and maintains joint integrity. The present investigation aimed to study the immunolocalization of lubricin in TMJ discs from patients affected by anterior disc displacement with reduction (ADDwR) ADDwoR. Eighteen TMJ displaced disc affected by ADDwoR were processed immunohistochemically, with a polyclonal anti-lubricin antibody, used at 1:50 working dilution. The percentage of lubricin immunopositive cells (extent score = ES) and the extent of lubricin staining of the disc extracellular matrix (ECM), were evaluated. Each sample was scored for histopathological changes. Percentage of immunostained surface disc cells was the same (ES = 4) in both control and ADDwOR cells, being this data not statistically significant (P < 0.05). In pathological specimens the percentages of lubricin-stained cells was very high with an ES of 4 respect to control specimen, and this difference was statistically significant different (P > 0.05). The extracellular matrix (ECM) of discs at the disc surfaces of both pathological and normal specimens was very heavily stained (++++). Both the ES and ECM staining were not statistically correlated to the TMJ degeneration score according to the Spearman’s rank correlation coefficient. According to our findings, a longstanding TMJ disc injury, affects lubricin expression in the TMJ disc tissue and not its surfaces, moreover, lubricin immunostaining is not correlated to TMJ disc histopathological changes.

February 21, 2011 - Stability of treatment for anterior open-bite malocclusion: A meta-analysis

n the included case series publications, success of both the surgical group (SX) and non-surgical group (NSX) treatments of Anterior open-bite appeared to be greater than 75%. Because the SX and the NSX were examined in different studies and applied to different clinical populations, no direct assessment of comparative effectiveness was possible. The pooled results should be viewed with caution because of the lack of within-study control groups and the variability among studies.

February 18, 2011 - Diagnostic accuracy of clinical tests and signs of temporomandibular joint disorders: A systematic review of the literature

There are few stand-alone test findings that are compelling for the clinical diagnoses of sub-classifications of TMD. Only 3 studies presented in this literature review were of high quality suggesting a risk of diagnostic bias with the majority of these studies. Because most of the studies only compared sub-classifications of TMD, the diagnostic ability to rule out or rule in TMD from a competing disorder is still unknown.

February 17, 2011 - Temporomandibular Disorders and Associated Clinical Comorbidities

The data provide evidence that TMJD represent a spectrum of disorders with varying pathophysiologies, clinical manifestations, and associated comorbid conditions. The findings underscore the complex nature of TMJD, the need for more extensive interdisciplinary basic and clinical research, and the development of outcome-based strategies to more effectively diagnose, prevent, and treat these chronic, debilitating conditions.

February 14, 2011 - Estrogen in cycling rats alters gene expression in the temporomandibular joint, trigeminal ganglia and trigeminal subnucleus caudalis/upper cervical cord junction

Females report temporomandibular joint (TMJ) pain more than men and studies suggest estrogen modulates this pain response. Our goal in this study was to determine genes that are modulated by physiological levels of 17β-estradiol that could have a role in TMJ pain.

February 8, 2011 -Temporomandibular disorder patients’ journey through care

The experiences of patients with TMDs mirror experiences of other types of chronic illness. Mapping the journey through care for TMDs highlights the potential for interaction between the stages of the journey and the individual’s illness. It may be possible to target interventions at specific stages on the map to help minimize the psychosocial effects of TMDs.

February 7, 2011 - Traumatic Temporomandibular Joint Ankylosis: Our Classification and Treatment Experience

The new classification of TMJ ankylosis based on coronal CT scan is valuable in guiding clinical treatment. LAP with TMF is a good way to treat traumatic TMJ ankylosis when the medially displaced condylar head and disc are intact. CCG with TMF has a good result for type A4 ankylosis.

February 2011 - Temporomandibular joint (TMJ) pain revisited with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)

The contrast enhancement patterns in the retrodiscal tissues of the painful joints showed significant differences in comparison with the painless joints. This result supports the hypothesis defending that inflammation and increased vascularity are responsible from the TMJ pain. Besides, the measurements from the retrodiscal tissues of the joints with partial displacement show significant difference between the signals of the displaced and non-displaced parts of the joints. Dynamic contrast-enhanced imaging revealed that different disc malpositions create different contrast enhancement patterns. On this basis, it is assessed that the types of the disc malpositions, which are believed to be acquired pathologies, are correlated with the retrodiscal inflammation degrees.

January 25, 2011 - The efficacy of anticonvulsants on orofacial pain: a systematic review

There is limited to moderate evidence supporting the efficacy of commonly used anticonvulsants for treatment of patients with orofacial pain disorders. More randomized controlled trials are needed on the efficacy of anticonvulsants.

January, 12, 2011 - Rebooting the brain helps stop the ring of tinnitus in rats

NIH-funded researchers were able to eliminate tinnitus in a group of rats by stimulating a nerve in the neck while simultaneously playing a variety of sound tones over an extended period of time, says a study published today in the advance online publication of the journal Nature. The hallmark of tinnitus is often a persistent ringing in the ears that is annoying for some, debilitating for others, and currently incurable. Similar to pressing a reset button in the brain, this new therapy was found to help retrain the part of the brain that interprets sound so that errant neurons reverted back to their original state and the ringing disappeared.

January 10, 2011 - Effect of Screw Fixation on Temporomandibular Joint Condylar Prosthesis

The results of this study have shown that 3 staggered screws can provide optimal implant stability and bone stress and strain distributions in a TMJ condylar prosthesis.

January 3, 2011 - Influence of headache frequency on clinical signs and symptoms of TMD in subjects with temple headache and TMD pain

The relationship of the frequency of temple headache to signs and symptoms of temporomandibular joint (TMJ) disorders (TMD) was investigated in a subset of a larger convenience sample of community TMD cases. The study sample included 86 painful TMD, nonheadache subjects; 309 painful TMD subjects with varied frequency of temple headaches; and 149 subjects without painful TMD or headache for descriptive comparison. Painful TMD included Research Diagnostic Criteria for Temporomandibular Disorders diagnoses of myofascial pain, TMJ arthralgia, and TMJ osteoarthritis. Mild to moderate-intensity temple headaches were classified by frequency using criteria based on the International Classification of Headache Disorder, 2nd edition, classification of tension-type headache. Outcomes included TMD signs and symptoms (pain duration, pain intensity, number of painful masticatory sites on palpation, mandibular range of motion), pressure pain thresholds, and temple headache resulting from masticatory provocation tests. Trend analyses across the painful TMD groups showed a substantial trend for aggravation of all of the TMD signs and symptoms associated with increased frequency of the temple headaches. In addition, increased headache frequency showed significant trends associated with reduced PPTs and reported temple headache with masticatory provocation tests. In conclusion, these findings suggest that these headaches may be TMD related, as well as suggesting a possible role for peripheral and central sensitization in TMD patients.

January, 2011 - Whiplash-associated disorders and temporomandibular symptoms following motor-vehicle collisions

Recent research has shown that temporomandibular symptoms may be associated with or occur independently of whiplash-associated disorders related to motor-vehicle collisions. A PubMed/Medline search was conducted using the terms "temporomandibular disorders," "orofacial pain," "temporomandibular joint," "whiplash," and "whiplash-associated disorders and motor-vehicle accidents and motor-vehicle collisions" for the years 1995 to 2009. Systematic reviews, meta-analyses, and clinical studies were included if they addressed temporomandibular disorders, whiplash epidemiology, diagnosis, and prognosis. References in the selected articles were also reviewed (including those prior to 1995) if the articles specifically addressed the topic. An evidence base was established for general outcomes using the Oxford Centre for Evidence-Based Medicine Levels of Evidence. Temporomandibular symptoms may develop following motor-vehicle collisions and be more complex, representing a component of a symptom cluster of potentially regional and widespread pain impacted by psychosocial factors. Oral health care providers must be aware of the relationship between temporomandibular symptoms, whiplash-associated disorders, and trauma and the more complex nature of the symptoms for appropriate diagnosis and management. (Quintessence Int 2011;42:e1-e14).

December 23, 2010 - In vivo morphometric analysis of inflammatory condylar changes in rat temporomandibular joint

These results indicate that CFA causes dynamic morphological changes in the condyle and that our experimental approach will provide new insights into the subacute inflammatory processes in the TMJ.

December 6, 2010 - COMT moderates the relation of daily maladaptive coping and pain in fibromyalgia

The findings provide multimeasure and multimethod support for genetic moderation of a maladaptive coping and pain process, which has been previously characterized in a sample of postoperative shoulder pain patients. Further, the findings advance our understanding of the role of COMT in FM, suggesting that genetic variation in the val158met polymorphism may affect FM pain through pathways of pain-related cognition.

December 2, 2010 - Condylar Morphology After Temporomandibular Joint Discectomy With Interpositional Abdominal Dermis-Fat Graft

The findings of this study suggest that in cases where additional condylar surgery was undertaken, over two thirds of the joints (68.8%) showed evidence of remodeling on postoperative OPGs. The interpositional dermis-fat graft failed to prevent significant condylar changes (CMS = 2) in about one third of patients who underwent TMJ discectomy, with the youngest (mean, 30.2 years) and the oldest (mean, 55.6 years) patients being most susceptible to condylar resorption.

December 2, 2010 - Recovery after third-molar surgery: The effects of age and sex

Patients older than 21 and those who are female should be informed before removal of all 4 third molars that their oral function, lifestyle, and pain recovery will be prolonged compared with those who are younger and male.

November 2, 2010 -Technological devices in the diagnosis of temporomandibular disorders.

Claims have been made that certain diagnostic devices should be routinely used to differentiate between jaw dysfunction and normal variation and between various pathologic conditions of the temporomandibular joint. The claims that jaw-tracking devices have diagnostic value for detecting TMD are not well supported by the scientific evidence. The clinical usefulness of electromyography devices is limited because of technical, methodologic, and data interpretation problems, as well as significant overlap between asymptomatic and symptomatic groups. Claims for the use of sonography and vibratography machines to discriminate between various intracapsular TMJ conditions have not been substantiated by well-designed research. Until acceptable levels of technical and diagnostic validity have been clearly established, these diagnostic devices cannot be relied on as aids in differential diagnosis or in clinical decision making in the TMD field.

November, 2010 - Some Dogmas Related to Prosthodontics, Temporomandibular Disorders and Occlusion

It is the aim of this paper to give a few examples of dogmas related to prosthodontics and oral implants and to discuss the controversial role of occlusion in the aetiology of temporomandibular disorders. New knowledge is developing at a rapidly increasing rate in dentistry, as in other areas of society. Our lecturers at university taught us many useful things. But, as time goes by, what is still relevant? Some methods are so well established that they deserve to be called dogmas. It is implied that a dogma is not supported by strong evidence, even though it has existed and been practised for a long time. In the era of evidence-based dentistry it is appropriate to scrutinize such issues. A review of the current literature indicates that conflicting opinions exist concerning a number of common procedures in clinical dentistry, mainly due to a scarcity of good studies with unambiguous results. There is therefore a need for more high-quality clinical research in attempting to reach the goal of evidence-based clinical practice. The dental community should take an active part in this process.

October 13, 2010 - Randomized Clinical Trial of Treatment for TMJ Disc Displacement

Of the various conservative treatment modalities available for temporomandibular disorders, we believe that therapeutic exercise has a good prognosis, especially for anterior disc displacement without reduction. Since its effectiveness has not been extensively evaluated, we conducted a comparative study to verify the hypothesis that treatment efficacy would not differ for exercise and occlusal splints. Fifty-two individuals with anterior disc displacement without reduction were randomly assigned to a splint or a joint mobilization self-exercise treatment group. Four outcome variables were evaluated: (i) maximum mouth-opening range without and (ii) with pain, (iii) current maximum daily pain intensity, and (iv) limitation of daily functions. All outcome variables significantly improved after 8 weeks of treatment in both groups. In particular, the mouth opening range increased more in the exercise group than in the splint group. This result demonstrates that therapeutic exercise brings earlier recovery of jaw function compared with splints.

October, 2010 - Self-regulatory deficits in fibromyalgia and temporomandibular disorders

Chronic pain conditions such as fibromyalgia (FM) and temporomandibular disorders (TMDs) are accompanied by complex interactions of cognitive, emotional, and physiological disturbances. Such conditions are complicated and draining to live with, and successful adaptation may depend on ability to self-regulate. Self-regulation involves capacity to exercise control and guide or alter reactions and behavior, abilities essential for human adjustment. Research indicates that self-regulatory strength is a limited source that can be depleted or fatigued, however, and the current study aimed to show that patients with FM and TMD are vulnerable to self-regulatory fatigue as a consequence of their condition. Patients (N=50) and pain-free matched controls (N=50) were exposed to an experimental self-regulation task followed by a persistence task. Patients displayed significantly less capacity to persist on the subsequent task compared with controls. In fact, patients exposed to low self-regulatory effort displayed similar low persistence to patients and controls exposed to high self-regulatory effort, indicating that patients with chronic pain conditions may be suffering from chronic self-regulatory fatigue. Baseline heart rate variability, blood glucose, and cortisol predicted persistence, more so for controls than for patients, and more so in the low vs. high self-regulation condition. Impact of chronic pain conditions on self-regulatory effort was mediated by pain, but not by any other factors. The current study suggests that patients with chronic pain conditions likely suffer from chronic self-regulatory fatigue, and underlines the importance of taking self-regulatory capacity into account when aiming to understand and treat these complex conditions.

September 29, 2010 - N-Acetyl Cysteine Protects TMJ Chondrocytes from Oxidative Stress

These results indicate that NAC restores oxidative stress-induced cell death and severe functional impairment in TMJ chondrocytes, and warrant in vivo testing to explore its therapeutic potential as an anti-inflammatory agent.

September 6, 2010 - Oral and Maxillofacial Surgery and Chronic Painful Temporomandibular Disorders - A Systematic Review

These apparently contradictory approaches underline a belief that oral surgical trauma or gross malocclusion has a causative role in the onset of TMD. However, there was no overall evidence of a surgical causal etiology or orthognathic therapeutic value. This review emphasizes that it is in the patients' best interest to carry out prospective appropriately controlled randomized trials to clarify the situation.

September 5, 2010 - Pharmacological interventions for pain in patients with temporomandibular disorders

There is insufficient evidence to support or not support the effectiveness of the reported drugs for the management of pain due to TMD. There is a need for high quality RCTs to derive evidence of the effectiveness of pharmacological interventions to treat pain associated with TMD.

August 25, 2010 - Quality Difference in Craniofacial Pain of Cardiac vs. Dental Origin

Pain quality, intensity, and gender characteristics were assessed for referred craniofacial pain from dental (n = 359) vs cardiac (n = 115) origin. The pain descriptors “pressure” and “burning” were statistically associated with pain from cardiac origin, while “throbbing” and “aching” indicated an odontogenic cause. No gender differences were found. These data should now be added to those craniofacial pain characteristics already known to point to acute cardiac disease rather than dental pathology, i.e., pain provocation/aggravation by physical activity, pain relief at rest, and bilateralism. To initiate prompt and appropriate treatment, dental and medical clinicians as well as the public should be alert to those clinical characteristics of craniofacial pain of cardiac origin.

Summer 2010 - Systematic review and meta-analysis of randomized controlled trials evaluating intraoral orthopedic appliances for temporomandibular disorders

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.

August 5, 2010 - UNC researchers find way to block chronic pain

Researchers at the University of North Carolina at Chapel Hill have found a way to halt chronic pain by stealing a key molecule from a major pain pathway. The finding may dramatically reduce chronic pain in many surgical patients.

August 5, 2010 - Genetic clue to chronic pain could lead to new treatments for the condition

In a report published online today in Genome Research (http://www.genome.org), researchers have identified a gene associated with susceptibility to chronic pain in humans, signaling a significant step toward better understanding and treating the condition.

July 29, 2010 - Do computed tomography and magnetic resonance imaging add to temporomandibular joint disorder treatment? A systematic review of diagnostic efficacy

The absence of studies on the therapeutic efficacy of MRI and CT on TMJD reinforces the need for investment in decision-making studies; meanwhile, sectional imaging tests should be prescribed with caution, especially when health budgets are limited.

July 23, 2010 - Brief cognitive-behavioral treatment for TMD pain: Long-term outcomes and moderators of treatment

It was concluded that brief treatments can yield significant reductions in pain, life interference and depressive symptoms in TMD sufferers, and that the addition of cognitive-behavioral coping skills will add to efficacy, especially for those low in somatization, or high in readiness or self-efficacy.

July 22, 2010 - Study finds structural brain alterations in patients with irritable bowel syndrome

A large academic study has demonstrated structural changes in specific brain regions in female patients with irritable bowel syndrome (IBS), a condition that causes pain and discomfort in the abdomen, along with diarrhea, constipation or both.

These study findings show actual structural changes to the brain, which places IBS in the category of other pain disorders, such as lower back pain, temporomandibular joint disorder, migraines and hip pain — conditions in which some of the same anatomical brain changes have been observed, as well as other changes.

July 2010 - Orthodontics for treating temporomandibular joint (TMJ) disorders

There is no evidence about the effects of different types of orthodontic braces for problems associated with the joint between the lower jaw and skull. When the joint between the lower jaw and the base of the skull is not working well (temporomandibular disorders (TMD)), it can lead to abnormal jaw movement or locking, noises (clicking or grating), muscle spasms, tenderness or pain. TMD is very common, and it is believed by some that it may be caused by the occlusion (the way the teeth bite), trauma or psychological stress. There is also a belief that the pain associated with TMD is similar, in that respect, to low back pain and may be related to variations of a person's individual pain perception. Changes in the way the teeth meet can be produced by the use of active orthodontic appliances. This review found that there is no evidence from trials to show that active orthodontic treatment can prevent or relieve temporomandibular disorders adding support to teeth not being part of its cause. It is suspected that we do not know the real cause of TMD at present.

 July 2010 - Transcutaneous electrical nerve stimulation (TENS) for chronic pain

Despite the widespread use of TENS machines, the analgesic effectiveness of TENS still remains uncertain. This has mainly been due to inadequate methodology and reporting in earlier studies but more recent studies of TENS for chronic pain fail to offer necessary improvements in methodological rigour to define the place of TENS in chronic pain management with any certitude. The search process identified 124 studies; 25 met the inclusion criteria for evaluation in this review but there were insufficient extractable data to make meta-analysis possible. New studies of rigorous design and adequate size are needed before any evidence-based recommendations can be made for patients or health professionals.

July - Migraine is the Most Prevalent Primary Headache in Individuals with Temporomandibular Disorders

Migraine headache and temporomandibular disorders represent two conditions that affect a significant portion of the population. The relationship between tension-type headache, formerly called musculo-skeletal headache, and myalgia of the masticatory muscles has been known and demonstrated in many patients. However, few studies show a significant association between vascular headache or migraine and temporomandibular disorders. Increasing evidence suggests a potential link in the etiology and course of these seemingly distinct pain disorders. This paper reviews these two conditions and discusses the possible connection between migraine headache and temporomandibular disorders.

June 29, 2010 - Critical Appraisal of Methods Used in Randomized Controlled Trials of Treatments for Temporomandibular Disorders

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.

June 29, 2010 - Reviewing the Evidence: Can Cognitive Behavioral Therapy Improve Outcomes for Patients with Chronic Orofacial Pain?

Cognative Behavioral Therapy (CBT), either alone or in combination with biofeedback, conservative treatment and/or self-care, can improve outcomes for patients with TMD in secondary care. However, further research is needed to assess its effectiveness in primary care and in management of other chronic orofacial pain conditions. Further, the number of sessions needed, mode of delivery, and cost-effectiveness also remain unclear.

June 17, 2010 - Self-regulatory deficits in fibromyalgia and temporomandibular disorders

The current study suggests that patients with chronic pain conditions likely suffer from chronic self-regulatory fatigue, and underlines the importance of taking self-regulatory capacity into account when aiming to understand and treat these complex conditions.

June 2010 - Acupuncture in the Treatment of Pain in Temporomandibular Disorders: A Systematic Review and Meta-analysis of Randomized Controlled Trials

The results of this meta-analysis suggest that acupuncture is a reasonable adjunctive treatment for producing a short-term analgesic effect in patients with painful TMD symptoms. Although the results described are positive, the relevance of these results was limited by the fact that substantial bias was present. These findings must be confirmed by future RCTs that improve the methodologic deficiencies of the studies evaluated in this meta-analysis.

June 2010 - TMJ  Arthroscopy: Rare Neurological Complications Associated with Breach of the Skull Base

We report an interesting case of vertigo and palsies of the right oculomotor and trochlear nerves associated with fluid collection in the region of the ipsilateral temporal lobe and cavernous sinus after bilateral arthroscopy of the temporomandibular joint (TMJ).

June 2010 - Generalized Joint Hypermobility May Be A Risk Factor for Temporomandibular Disorders

 

June 2010 - Interactions of Glutamate and Capsaicin-evoked Muscle Pain on Jaw Motor Functions of Men

The present findings suggest that peripheral glutamate and capsaicin receptor mechanisms interact to affect some jaw motor as well as sensory (i.e. pain) functions and provide new insights into the complexity of orofacial pain. Management approaches that target the peripheral nervous system and receptor mechanisms may prevent such changes in jaw motor function.

May 25, 2010 - NIDCR: Developing Research Capacity in Temporomandibular Disorders and Orofacial Pain Research

The overall goal of this Initiative is to expand the community of researchers engaged in research on temporomandibular disorders (TMJD) and orofacial pain. Several centers of excellence in TMJD research exist. However, an expansion of this field is necessary to reach a critical mass of scientists with new and complementary expertise who will be able to leverage recent advances in genetics, bio-engineering, and bio-behavioral research. The objectives of this Initiative are to 1) increase the number of basic and clinical investigators who are trained in TMJD or orofacial pain research, 2) facilitate and improve the mentoring of this new group of scientists, 3) expand the expertise and scientific disciplines that can be applied to TMJD and orofacial pain research. The expected outcome of this Initiative will be an increased number of multidisciplinary research teams led by new, young investigators. These new teams will form a robust research community applying novel approaches to TMJD and orofacial pain research that will enhance our understanding of the disorders and lead to effective treatments for patients. 

May 24, 2010 - Referred Pain from Muscle Trigger Points in the Masticatory and Neck-Shoulder Musculature in Women with Temporomandibular Disorders

The current study showed the existence of multiple active muscle TrPs in the masticatory and neck-shoulder muscles in women with myofascial TMD pain. The local and referred pain elicited from active TrPs reproduced pain complaints in these patients. Further, referred pain areas were larger in TMD pain patients than in healthy controls. The results are also in accordance with the notion of peripheral and central sensitization mechanisms in patients with myofascial TMD.

May 18, 2010 - What you can and cannot see in TMJ imaging; an overview related to the RDC/TMD diagnostic system

In the current version (I) of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), imaging of the temporomandibular joint (TMJ) is not required for a diagnosis. Research has shown that radiological findings of the TMJ do not always support the clinical findings of the RDC/TMD diagnosis. But imaging should only be performed when it is known that it could contribute to (i) a proper diagnosis and (ii) treatment with a better prognosis. Several techniques are used to image the TMJ: panoramic radiography, plain radiography, conventional and computed tomography (CT), digital volume tomography or cone-beam computed tomography (CBCT), arthrography and magnetic resonance imaging (MRI). Osseous changes are best visualized in tomography, and the newly developed CBCT is a promising method but must be evaluated in a comparative analysis with other tomographic techniques. And although MRI is the method of choice for imaging the disc, a systematic review found the evidence grade for the diagnostic efficacy of MRI to be insufficient. Today, there is no clear evidence for when TMD patients should be examined with imaging methods. Future research designs should be randomized controlled trials where various radiological examination findings are analysed in relation to therapeutic outcome. In future versions of the RDC/TMD diagnostic system, recommended radiographic techniques must be evaluated and defined, diagnostic criteria well defined and observers calibrated.

May 13, 2010 - The Effect of Fibromyalgia and Widespread Pain on the Clinically Significant Temporomandibular Muscle and Joint Pain Disorders-A Prospective 18-Month Cohort Study

Although most cases of temporomandibular muscle and joint disorders (TMJD) are mild and self-limiting, about 10% of TMJD patients develop severe disorders associated with chronic pain and disability. It has been suggested that fibromyalgia and widespread pain play a significant role in TMJD chronicity. This paper assessed the effects of fibromyalgia and widespread pain on clinically significant TMJD pain (GCPS II-IV). Four hundred eighty-five participants recruited from the Minneapolis/St. Paul area through media advertisements and local dentists received examinations and completed the Graded Chronic Pain Scale (GCPS) at baseline and at 18 months. Baseline widespread pain (OR: 2.53, P = .04) and depression (OR: 5.30, P = .005) were associated with onset of clinically significant pain (GCPS II-IV) within 18 months after baseline. The risk associated with baseline fibromyalgia was moderate, but not significant (OR: 2.74, P = .09). Persistence of clinically significant pain was related to fibromyalgia (OR: 2.48, P = .02) and depression (OR: 2.48, P = .02). These results indicate that these centrally generated pain conditions play a role in the onset and persistence of clinically significant TMJD.

May 12, 2010 - Temporomandibular Disorder Modifies Cortical Response to Tactile Stimulation

This article presents evidence that central processing of innocuous tactile stimulation is abnormal in TMD. Understanding the complexity of sensory disruption in chronic pain could lead to improved methods for assessing cerebral cortical function in these patients.

May 2010 - Acupuncture for Temporomandibular Disorders: A Systematic Review

This systematic review noted moderate evidence that acupuncture is an effective intervention to reduce symptoms associated with TMD. There is a need for acupuncture trials with adequate sample sizes that address the long-term efficacy or effectiveness of acupuncture.J Orofac Pain 2010;24:152-162.

May 2010 - Glutamate-induced Temporomandibular Joint Pain in Healthy Individuals is Partially Mediated by Peripheral NMDA Receptors

Glutamate evokes immediate pain in the healthy human TMJ that is partly mediated by peripheral NMDA receptors in the TMJ.  J Orofac Pain 2010;24:172-180.

May 5, 2010 - First Results from OPPERA, the  $19 Million Jaw Pain Study  Unveiled

Scientists will report results from the first three years of the world's first-ever large, prospective clinical study to identify risk factors that contribute to someone developing a TMJ disorder.

April 28, 2010 - Side Effects of Stabilization Occlusal Splints: A report of Three Cases and Literature Review

Stabilization splints are frequently used for the treatment of temporomandibular disorders (TMD) and bruxism, despite the fact that little is known about their mechanism of action or the precise conditions under which they can be recommended. Moreover, information about their possible adverse effects, which in the majority of cases include occlusal modifications of little clinical relevance, is scarce. On occasions, these splints can provoke severe occlusal alterations and other complications, which are rarely alluded to in the literature. Here presented in this paper are three case reports in which part-time stabilization splints led to irreversible occlusal alterations and a discussion of the relevant clinical implications. Such splints are reported to negatively affect the condyle-disk relation in patients who exhibit disk displacement with reduction and to modify breathing features in patients with obstructive sleep apnea, although further studies are required to unequivocally demonstrate these findings. Finally, the splint seems to modify peripheral information at the level of the Central Nervous System, leading to modifications in corporal postural tone. The clinical repercussions of such alterations are currently poorly understood. It is our hope that future research will throw fresh light on these important topics.

April 16, 2010 - Living with Uncertainty: Temporomandibular Disorders

Temporomandibular disorders (TMDs) are a common group of chronic illnesses. There is evidence that health professionals find them difficult to diagnose and manage. A consequence of this difficulty in diagnosis might be that sufferers of TMDs have an experience of illness comparable with other chronic illnesses. To explore the sufferers’ experience of TMDs, we conducted a qualitative study with a purposive maximum variation sample of secondary care TMD patients. Semi-structured interviews were conducted with the sample and were recorded and transcribed verbatim. Data collection and analysis continued until data saturation (n = 19). For analysis, we broadly followed the constant comparative method and used frameworks to organize the data. The key finding was that a lack of diagnosis caused uncertainty over the nature of the cause of the sufferer’s complaint. This uncertainty reportedly caused negative impacts on sufferers’ daily lives. Clearly, diagnosis of TMDs needs to be encouraged at the first point of contact.

April 8, 2010 - American Academy of  Dental Research (AADR) Policy Statement on TMJ Disorders

The AADR recognizes that temporomandibular disorders (TMDs) encompass a group of musculoskeletal and neuromuscular conditions that involve the temporomandibular joints (TMJs), the masticatory muscles, and all associated tissues. The signs and symptoms associated with these disorders are diverse, and may include difficulties with chewing, speaking, and other orofacial functions. They also are frequently associated with acute or persistent pain, and the patients often suffer from other painful disorders (comorbidities). The chronic forms of TMD pain may lead to absence from or impairment of work or social interactions, resulting in an overall reduction in the quality of life.

March 24, 2010 - Medication-Overuse Headache

Clinical features, pathophysiology, and treatment of medication-overuse headache. Medication-overuse headache (MOH) is a chronic headache disorder defined by the International Headache Society as a headache induced by the overuse of analgesics, triptans, or other acute headache compounds. The population-based prevalence of MOH is 0·7% to 1·7%. Most patients with MOH have migraine as their primary headache and overuse triptans or simple analgesics. The pathophysiology of MOH is still unknown. As well as psychological mechanisms such as operant conditioning, changes in endocrinological homoeostasis and neurophysiological changes have been observed in patients with MOH. Recently, a genetic susceptibility has been postulated. In most cases, treatment of MOH consists of abrupt withdrawal therapy and then initiation of an appropriate preventive drug therapy. There is no clear evidence on which method of withdrawal therapy is the most efficacious. Withdrawal symptoms can be treated with steroids; however, not all data support this concept. As MOH can severely affect the quality of life of patients, it needs to be recognised early to enable appropriate treatment to be initiated.

April 2, 2010 - TMJ arthroscopy: rare neurological complications associated with breach of the skull base

We report an interesting case of vertigo and palsies of the right oculomotor and trochlear nerves associated with fluid collection in the region of the ipsilateral temporal lobe and cavernous sinus after bilateral arthroscopy of the temporomandibular joint (TMJ).

March 18, 2010 - Evaluating MRI Interpretations of the TMJ

Evaluation of the reproducibility in the interpretation of magnetic resonance images of the temporomandibular joint.  Examiners do not demonstrate reproducibility in the interpretation of MRI of temporomandibular joints. Therefore, more efforts are necessary with respect to understanding the changes that may be detected in these images in terms of diagnosis and appropriate treatment approaches.

March 18, 2010 - TMJ Pain Associated with Neural Abnormalities

Chronic myofascial temporomandibular pain is associated with neural abnormalities in the trigeminal and limbic systems.  Myofascial pain of the temporomandibular region (M–TMD) is a common, but poorly understood chronic disorder. It is unknown whether the condition is a peripheral problem, or a disorder of the central nervous system (CNS)...The pattern of gray matter abnormality found in M–TMD individuals suggests the involvement of trigeminal and limbic system dysregulation, as well as potential somatotopic reorganization in the putamen, thalamus, and somatosensory cortex.

March 12, 2010 -Pathophysiology of TMD Pain

Pathophysiology of TMD pain - basic mechanisms and their implications for pharmacotherapy. This article discusses the pathophysiology of temporomandibular disorders (TMD)–related pain and its treatment with analgesic drugs. Temporomandibular disorders are comprised of a group of conditions that result in temporomandibular joint pain (arthralgia, arthritis) and/or masticatory muscle pain (myofascial TMD). In at least some patients with TMD, a peripheral mechanism contributes to this pain. However, there is often a poor correlation between the severity of TMD–related pain complaints and evidence of definitive tissue pathology. This has led to the concept that pain in some patients with TMD may result from altered central nervous system pain processing and further that this altered pain processing may be attributable to specific genes that are heritable. Psychosocial stressors are also thought to contribute to the development of TMD–related pain, particularly masticatory muscle pain. Finally, substantially more women suffer from TMD than men.

 February 17, 2010 - TMJ Disorders Associated with  Increased Body Pain

Development of Temporomandibular Disorders is Associated with Greater Bodily Pain Experience.  This is a 3–year prospective study of 266 females aged 18 to 34 years initially free of temporomandibular disorders (TMD) pain. All patients completed the Symptom Report Questionnaire (SRQ) at baseline and yearly intervals, and at the time they developed TMD (if applicable)...The development of TMD was accompanied by increases in headaches, muscle soreness or pain, and other pains that were not observed in the Participants who did not develop TMD. Participants who developed TMD also report higher experience of joint, back, chest, and menstrual pain at baseline. Click here to read the abstract.

January 29, 2010 - Impact of Tobacco Use on the Symptoms of Painful Temporomandibular Joint Disorders

Smoking and other types of tobacco use may increase the pain of temporomandibular joint disorders, a new study suggests.  Click here to view the abstract summary in the publication Pain, December 15, 2009.

January 27, 2010 - Effectiveness of Acupuncture in the Treatment of Temporomandibular Disorders of Muscular Origin: A Systematic Review of the Last Decade

Click here to read the TMJ Science Publications Archives.