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.
Volunteers with mild symptoms had a prevalence of disk displacement of the same magnitude as that reported in patients, although most volunteers, symptomatic as well as asymptomatic, maintained their TMJ status during 15 years.
As more than 60 percent of women with temporomandibular disorders (TMD) also exhibit abdominal pain consistent with irritable bowel syndrome (IBS) symptoms, two researchers in the neural and pain sciences department of the University of Maryland School of Dentistry, in Baltimore, have developed a model to better illustrate the two conditions’ comorbidity.
For patients in whom conservative treatment was adopted, the laser acupuncture is a secure, noninvasive, and effective treatment modality because it improves the chronic pain associated with TMD and has no side effects.
The current level of evidence allows only very limited conclusions on the effect of intra-articular coricosteroid injection (IACI) therapy in patients with TMJ arthritis. Knowledge on the long-term impact of IACI on mandibular growth is not available. Future studies designed in accordance with evidence-based standards are needed to allow a more general conclusion on efficacy and safety of this treatment modality in patients with TMJ arthritis.
Symptoms of central sensitization syndrome (CSS) were evaluated among three different groups of temporomandibular disorder (TMD) patients. Additionally, TMD group differences in pain and pain-related disability were assessed, as well as emotional distress. Participants were 250 patients with symptoms of acute TMD, recruited from dental clinics within a major metropolitan area. Sequential regressions and multivariate analyses of covariance were conducted in order to make group comparisons. Those with a TMD Muscle Disorder (ie, myofacial TMD [m-TMD]) and those with more than one TMD diagnosis had the most symptoms of CSS and higher reports of pain and pain-related disability. Moreover, emotional distress accounted for a substantial amount of the variance for physical symptoms and mediated all TMD comparisons. Myofacial TMD is characterized by a high degree of comorbidity of symptoms of CSS and associated emotional distress.
The role of temporomandibular joint (TMJ) surgery is ill-defined, so a universal classification is needed to collate the evidence required to justify the surgical interventions undertaken to treat TMJ disorders. The aim of this article is to introduce a new classification that divides TMJ disorders into 5 categories of escalating degrees of joint disease that can be applied to TMJ surgery. Using a category scale from 1 to 5, with category 1 being normal, and category 5 referring to catastrophic changes to the joint, the new classification will provide the basis for enhanced quantitative and descriptive data collection that can be used in the field of TMJ surgery research and clinical practice. It is hoped that this new classification will form the basis of what will eventually become the universal standard surgical classification of TMJ disorders that will be adopted by both researchers and clinicians so that ultimately, the role of TMJ surgery will be based on evidence rather than conjecture.
Although other reasons to consider treating sleep bruxism (SB) may exist, misplaced concern about SB's sustaining or exacerbating a chronic myofascial TMD condition should not be used to justify SB treatment.
Taken together, these data suggest that TMD subjects have an impairment of the sympathetic-adrenergic component of the ANS to be activated under stress. The present study provides preliminary pupillometric data confirming that adrenergic function is dysregulated in patients with TMD
Volunteers with mild symptoms had a prevalence of disk displacement of the same magnitude as that reported in patients, although most volunteers, symptomatic as well as asymptomatic, maintained their TMJ status during 15 years
Results. There was a significant increase in the pressure pain threshold of the examined muscles. Mandibular movements were significantly improved in all patients. There was also a significant decrease in pain by palpation after laser exposure. However, no significant change was found in the maximum bite force, occlusal contact area or occlusal pressure after the treatment and also the values after the treatment were still significantly lower than those of the healthy individuals. Conclusion. This particular type of LLLT is effective at relieving pain but does not provide physical improvement.
The results showed that the sheep is an excellent experimental model for the study of condylar growth, with and without the use of functional appliances, because of similarity in anatomy related to size, shape and position of the condyle to that of human beings. Thus, it is concluded that the study will help future investigators in the field of dentistry to consider the sheep as an experimental animal for further research.
This study provides additional evidence supporting the analgesic effects of melatonin on pain scores and analgesic consumption in patients with mild-to-moderate chronic myofascial TMD pain. Furthermore, melatonin improves sleep quality but its effect on pain appears to be independent of changes in sleep quality.
A team of Korean researchers decided to see if the vestibular nuclei were affected in cases of jaw inflammation by means of simulating TMD in animal models. The team used two groups of rats. One group was injected with an inflammatory agent in the right TMJ. The other was a control group injected in the right TMJ with normal saline. They waited 24 hours and then studied neural activity in the vestibular nuclei. Sure enough, they noted signs of increased activity in the vestibular nuclei on both sides in both the experimental and control groups, but much greater activity in the nuclei of the experimental animals on the inflamed jaw side provide grounds for suspecting that symptoms of dizziness might well reflect abnormal vestibular activity as a result of TMJ inflammation.
TMD subjects with widespread body palpation tenderness (WPT) experience a greater level of multiple comorbid pain conditions, compared to TMD subjects without WPT and non-TMD controls. Integration of bodily pain assessments can be informative for evaluation, diagnosis, and management of TMD.
The present study demonstrates a lack of endogenous pain inhibitory pathways, and in particularly conditioned pain modulation, in patients with chronic whiplash–associated disorders (WAD), and hence provides additional evidence for the presence of central sensitization in chronic WAD.
Internet posts in online discussion forums, in which patients with TMJ request information, are important sources of knowledge, because they reflect the feelings, concerns, and interpretations of those affected in an unadulterated form. Users participating in the ensuing discussion threads may be expected to offer not only empathy but also concrete proposals for further action. However, the recommendations made are not always reliable. Statements on the etiology and prognosis of the disorder are highly problematic, as they embody concepts that reinforce fear and contribute to a chronic outlook. It would therefore be highly desirable for professional societies or organizations to offer high-quality patient information on the web. This information should be regularly updated to reflect the current therapies available.
There is no evidence to support or reject the hypothesis that hypoxia reperfusion occurs in TMJ OA, and limited evidence is provided to support that hypoxia-reperfusion injury occurs in OA of the knee joint. Since the studies suggest differences between OA and other types of arthritis in relation to hypoxia-reperfusion mechanisms, further research in this field needs to distinguish OA from other types of arthritis.
The objective of this review is to discuss the proposed pathophysiologic mechanisms, which have been similarly studied in these conditions. These mechanisms include enhanced pain perception, altered regional brain activation, infectious etiologies, dysregulations in immune and neuroendocrine function, and genetic susceptibility. Studies suggest that these functional disorders are multifactorial, but factors which increase the vulnerability of developing these conditions are shared.
Based on these results, we conclude that sensory information is processed by TMJ neurons encoding at least joint position and displacement in the physiological range of mandibular displacement.
The findings of this study did not show that stabilization splint treatment in combination with counselling and masticatory muscle exercises has additional benefit in relieving facial pain and increasing the mobility of the mandible than counselling and masticatory muscle exercises alone in a short time-interval.
The current study aimed to research the prevalence of temporomandibular disorders (TMD) in patients with subjective tinnitus, as compared to controls, and the association between symptoms of TMD, tinnitus, and chronic pain. Two hundred patients were divided into two groups, according to the presence (experimental) or not (control) of subjective tinnitus. The subgroups were determined according to the RDC/TMD criteria. The Pain Pressure Threshold (PPT) values of the masseter and temporalis muscles were recorded bilaterally, and a Visual Analog Scale (VAS) was used to address subjective pain. The most prevalent TMD subgroups in the tinnitus patients (p<0.05) were myofascial pain with limited opening (39.0%), disc displacement with reduction (44.33%), and arthralgia (53.54%). The severity of tinnitus was significantly associated with the severity of chronic pain (p=.000). The PPT values were lower (p>0.05), while the Visual Analog Scale (VAS) was statistically higher (p=.000) for the tinnitus patients. These results suggest that an association exists between TMD and subjective tinnitus.
Similar to females, male rats with TMJ inflammation showed a reduced nociceptive response after treatment with a physiological concentration of oestradiol suggesting the effects of oestradiol treatment were not constrained by organizational processes in the males.
Replicating previous work in tinnitus patients with TMJ complaints, classical risk factors for tinnitus like older age and male gender are less relevant in tinnitus patients with TMJ complaints. By demonstrating group differences for modulation of tinnitus by movements and sounds our data further support the notion that tinnitus with TMJ complaints represents a subgroup of tinnitus with clinical features that are highly relevant for specific therapeutic management.
The 5-hydroxytryptamine (serotonin, 5-HT) is an important inflammatory mediator found in high levels in the synovial fluid of the temporomandibular joint (TMJ) of patients with inflammatory pain. In this study, we used the nociceptive behavior responses, measured as flinching the head and rubbing the orofacial region, as a nociceptive assay. We demonstrated that the local blockade of the 5-HT(3) receptor and β(1) or β(2)-adrenoceptors, the depletion of norepinephrine in the sympathetic terminals and the local inhibition of cyclooxygenase significantly reduced 5-HT-induced TMJ nociception. These results demonstrated that 5-HT induces nociception in the TMJ region by the activation of β(1) and β(2) adrenoceptors located in the TMJ region and local release of sympathetic amines and prostaglandins. Therefore, the high levels of 5-HT in the synovial fluid of patients with TMJ inflammatory pain may contribute to TMJ pain by similar mechanisms
Participants with multiple diagnoses reported higher pain, as well as other symptoms, relative to participants without a TMD diagnosis. For chewing performance, participants with mutual diagnoses reported more pain compared to other participants. Finally, the risk-status of patients significantly affected chewing performance.
Temporomandibular disorder (TMD) is a prevalent chronic pain disorder that remains poorly understood. Recent imaging studies reported functional and gray matter abnormalities in brain areas implicated in sensorimotor, modulatory, and cognitive function in TMD, but it is not known whether there are white matter (WM) abnormalities along the trigeminal nerve (CNV) or in the brain. Here, we used diffusion tensor imaging, and found that, compared to healthy controls, TMD patients had 1) lower fractional anisotropy (FA) in both CNVs; 2) a negative correlation between FA of the right CNV and pain duration; and 3) diffuse abnormalities in the microstructure of WM tracts related to sensory, motor, cognitive, and pain functions, with a highly significant focal abnormality in the corpus callosum. Using probabilistic tractography, we found that the corpus callosum in patients had a higher connection probability to the frontal pole, and a lower connection probability to the dorsolateral prefrontal cortex, compared to controls. Finally, we found that 1) FA in tracts adjacent to the ventrolateral prefrontal cortex and tracts coursing through the thalamus negatively correlated with pain intensity; 2) FA in the internal capsule negatively correlated with pain intensity and unpleasantness; and 3) decreases in brain FA were associated with increases in mean diffusivity and radial diffusivity, markers of inflammation and oedema. These data provide novel evidence for CNV microstructural abnormalities that may be caused by increased nociceptive activity, accompanied by abnormalities along central WM pathways in TMD.
The authors briefly discuss the clinical commonalities of migraine and temporomandibular disorders (TMD), and the differential diagnosis of these conditions with other causes of facial pain. They close by presenting the experience in the treatment of patients with the comorbidity.
This short–term observational study suggests that there are no major differences between patients with different craniofacial pain conditions and pain–free individuals in terms of jaw–muscle electromyographic (EMG) activity recorded with a single–channel EMG device during sleep. However, some associations may exist between the level of EMG activity and various parameters of craniofacial pain. Longitudinal studies are warranted to further explore the relationship between sleep bruxism and craniofacial pain.
Headaches and facial pain are common in the general population. In many cases, facial pain can be resultant from temporomandibular joint disorders. Studies have identified an association between headaches and temporomandibular joint disorders suggesting the possibility of shared pathophysiologic mechanisms of these 2 maladies. The aim of this paper is to elucidate potential commonalities of these disorders and to provide a brief overview of an examination protocol that may benefit the headache clinician in daily practice.
Background: Internal derangement is the most frequent arthropathy affecting the temporomandibular joint, where its commonest form is anterior disc displacement with or without reduction. Despite the frequency of the disorder, the biochemical features of displaced discs are still unclear. Methods: We investigated the expression pattern and localization of aquaporin-1, an important channel protein involved in plasma membrane water permeability, in patients with anterior disc displacement (both with and without reduction), with a view to assessing the characteristics of local tissue responses to the microenvironmental changes induced by abnormal mechanical loading of the displaced disc. Protein expression was studied by immunohistochemistry in different areas of discs from 18 patients with anterior disc displacement with or without reduction and in four normal controls. Results: A greater proportion of cells immunopositive for aquaporin-1 were detected in diseased than in normal discs. Whereas protein expression was substantially similar in the different areas of normal discs, a significantly larger number of immunopositive cells were detected in the posterior band of displaced discs without reduction and in the anterior and intermediate bands of those with reduction. Conclusions: These findings suggest that aquaporin-1 is expressed and upregulated in temporomandibular joint with anterior disc displacement (both with and without reduction).
The hippocampus is believed to play an important role in sex-based differences of pain perception. Whether estrogen potentiates allodynia in the inflamed temporomandibular joint (TMJ) through affecting the expressions of pain-related genes in the hippocampus remains largely unknown. Because the nerve growth factor (NGF) is an important gene related to inflammatory pain, we tested whether hippocampal NGF may be involved in TMJ inflammatory pain. Here we showed that the rat hippocampal NGF was upregulated by TMJ inflammation induced by complete Freund adjuvant. NGF upregulation was further potentiated by estradiol in a dose-dependent manner. In contrast, NGF transcription in the amygdala, prefrontal cortex, and thalamus was not affected by TMJ inflammation and estradiol. An intrahippocampal injection of NGF antibody or NGF receptor inhibitor K252a (inhibitor for tropomyosin receptor kinase A, TrkA) reduced the allodynia of inflamed TMJ in proestrous rats. Our data suggest that the hippocampal NGF is involved in estradiol-sensitized allodynia of inflammatory TMJ pain.
Temporomandibular disorders are among the potential comorbidities of migraine, and recent reports showed that they may have a role in promoting its progression into chronic migraine (CM). In order to clarify the possible role of neuromuscular components of the stomatognathic system in patients with CM, we studied 18 patients admitted as inpatients at our Headache Unit to undergo a withdrawal protocol for medication overuse, who underwent orthosis, after clinical and instrumental gnathological evaluation. They were subsequently evaluated after 6 months. The values of electromyographic parameters as well as of pain outcomes showed a significant decrease after orthosis. The implementation of gnathological and neuromuscular concepts can have a relevant role in the management of CM patients, in the contest of a multidisciplinary approach.
The findings are consistent with the hypothesis that sustained TMJ inflammation, even within the presently observed 35 days, may be a predisposing factor for structural abnormalities. Insight into TMJ inflammation and degeneration is anticipated to improve the understanding of the pathogenesis of TMJ arthritis and help design clinically relevant strategies for tissue engineering.
Headaches and facial pain are common in the general population. In many cases, facial pain can be resultant from temporomandibular joint disorders. Studies have identified an association between headaches and temporomandibular joint disorders suggesting the possibility of shared pathophysiologic mechanisms of these 2 maladies. The aim of this paper is to elucidate potential commonalities of these disorders and to provide a brief overview of an examination protocol that may benefit the headache clinician in daily practice.
There is no evidence for the existence of a predictable relationship between occlusal and postural features, and it is clear that the presence of temporomandibular disorders (TMD) pain is not related with the existence of measurable occluso–postural abnormalities. Therefore, the use instruments and techniques aiming to measure purported occlusal, electromyographic, kinesiographic or posturographic abnormalities cannot be justified in the evidence–based TMD practice.
In view of the paucity of high level evidence for the effectiveness of interventions for the management of TMJ OA, small parallel group RCTs which include participants with a clear diagnosis of TMJ OA should be encouraged and especially studies evaluating some of the possible surgical interventions.
Symptom improvement after insertion of an oral splint or after occlusal adjustment does not prove an occlusal aetiology either, because the amelioration may be due to the change of the appliance–induced intermaxillary relationship. In addition, symptoms often abate even in the absence of therapy. Although patients with a TMD history might have a specific risk for developing TMD signs, it appears more rewarding to focus on non–occlusal features that are known to have a potential for the predisposition, initiation or perpetuation of TMDs.
The authors of this systematic review found no evidence to support the use of EMG for the diagnosis of TMD.
These findings indicate that the mature articular cells are capable of producing desmin instead of the other intermediate filaments against mechanical stress. The desmin-positive disc cells lacked α-smooth muscle actin (α-SMA) in this study, even though desmin usually co-exists with α-SMA in the vascular smooth muscle cells or pericytes. Because the precursor of a pericyte has such an immunoexpression pattern during angiogenesis, there is a further possibility that the formation of new vessels commenced in response to the extraordinary compressive force.
The interaction between time and treatment group was not significant. Hence, physical therapy had no significant additional effect in patients with anterior disc displacement, without reduction, of the temporomandibular joint.
Thus, there is a high prevalence of signs and symptoms of TMD in FM patients, indicating the need for an integrated diagnosis and treatment of these patients, which suggest that the FM could be a medium- or long-term risk factor for the development of TMD.
The analyses suggest the existence of different interindividual responses to climatic changes. However, the identified putative role of meteorological variables and of their two–way interactions suggests that further investigations on larger samples may be useful to assess the research question under examination.
There is no evidence to show that acupuncture is an effective treatment for Temporomandibular joint dysfunction (TMJD). The few existing randomised controlled trials (RCTs) are of poor methodological quality.
Findings demonstrate the importance of regulated RTK signaling during TMJ development and suggest multiple skeletal origins for the fossa. Notably, our work provides the evidence that the TMJ condyle and disc develop independently of the mandibular fossa.
The authors concluded currently, there is no evidence to support the effectiveness of Low-level laser therapy in the treatment of TMD.
The study demonstrated a significant positive effect of informing and instructing patients with anterior disc displacement without reduction. Physical therapy did not have an additional effect. The results confirmed that, in most patients, the natural course of TMJ closed lock is benign and self-limiting, probably because of the adaptive capacity of the structures involved. A conservative approach of providing information and instruction, therefore is warranted.
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.
During a short period, education was slightly more effective than an occlusal splint delivered without education in reducing spontaneous muscle pain in patients with TMD. Pain-free mouth opening, headache and pain during chewing were not significantly different between the two treatments.
In this study, muscle activity was analyzed electromyographically in healthy controls, patients with myogenous (muscle) TMD and those with mixed (muscle and joint) TMD while performing a muscle endurance test. The results showed that the cervical muscles fatigued more quickly in the TMD patients than in the control subjects. Thus, such patients may develop neck and shoulder pain more easily than normal persons.
Researchers studying an experimental TMJ pain model in rats have noted that pain in these female animals appears to be reduced in the pre-ovulatory phase when estrogen levels are highest. Now, a team of scientists, headed by Dr. Philip Kramer at Texas A&M Health Science Center, Baylor College of Dentistry, have screened animals' nerve tissue that supplies sensation to the TM joint area to see whether there are specific genes which are turned on in response to stimulation by estrogen. (There are estrogen receptors in the nerve tissue of interest.) Their article cites two genes in particular which code for proteins that can reduce pain signals from the joint area and which are more active (gene expression is increased) in response to estrogen. In continuing studies the researchers are manipulating expression of these genes to see how changes in gene activity affect the animals’ pain behavior and whether this is, in fact, the mechanism by which estrogen affects responses to pain.
Subjects with temporomandibular joint ankylosis who underwent gap arthroplasty had significantly better postoperative maximal incisal opening than those undergoing ankylosis resection and ramus-condyle unit reconstruction with a costochondral graft.
This study demonstrates that patients with depression are at an elevated risk of developing TMD.
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:
Temporomandibular disorders (TMD) consist of a heterogeneous family of musculoskeletal disorders that represent the most common chronic orofacial pain condition.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Oral glucosamine sulfate was not superior to placebo in reducing signs and symptoms of osteoarthritis in the TMJs in this short-term trial.
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.
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.
Mouth opening limitation after the neurosurgical procedures is a common complication and usually resolves within 3 months. If limited mouth opening remains unresolved on the long term, an intra-articular ankylosis of temporomandibular joint may develop eventually. The possible mechanisms base on the myositis and atrophy of the masticatory muscles for these craniotomies are often involved in the temporalis. This article reports two unusual cases with the intra-articular ankylosis of temporomandibular joint after the traumatic brain injury, who received a modified surgical treatment for joint ankylosis. Therefore, the early diagnosis and intervention are important to minimize these complications.
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/C1–2) 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/C1–2 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.
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.
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.
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.
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.
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.
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.
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.
These results suggest that estradiol aggravates TMJ inflammation through the NF-κB pathway, leading to the induction of proinflammatory cytokines.
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.
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
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.
TMD findings associate with pain in several locations. Female gender and presence of impaired health were particularly related to occurrence of multiple pain conditions.
Persistent joint pain after arthrocentesis is generally associated with extensive amounts of joint effusion or erosive cortical changes of the condyle.
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, 23–71
years) 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.
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.
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.
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.
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.
Hypnosis thus seems to reduce complex temporomandibular disorder pain, most likely because of cortical changes with little, if any, involvement of brainstem reflex pathways.
Some genetic polymorphisms related to folates metabolism, inflammatory oxidative stress, and neurotransmission responses to pain, has been significantly associated to TMD syndrome.
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.
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.
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
This systematic review and meta–analysis demonstrate that the evidence for acupuncture as a symptomatic treatment of temporomandibular joint disorder (TMD) is limited.
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.
A sound understanding of biomechanical behavior of TMJ (Temporomandibular Joint) disc is necessary for evaluation and treatment of various temporomandibular joint disorders.
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.
Hypnosis thus seems to reduce complex temporomandibular disorder pain, most likely because of cortical changes with little, if any, involvement of brainstem reflex pathways.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
The literature search yielded 584 titles and abstracts, of which 257 were selected and read in full text. One study was judged relevant. This study evaluated evidence of the efficacy of MRI in the diagnosis of disc position and configuration, disc perforation, joint effusion, and osseous and bone marrow changes in the temporomandibular joint, but no publication reported diagnostic thinking efficacy or therapeutic efficacy. In conclusion, 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.
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.
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.
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.
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.
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).
To view or order a free booklet about TMJ Disorders, visit the National Institutes of Health website.
Site operated by The TMJ Association, Ltd. (TMJA) is a non-profit, 501(c)(3) tax exempt organization. ©2009-2010 The TMJ Association, Ltd. All rights reserved.
The TMJ Association, Ltd., P.O. Box 26770, Milwaukee WI 53226. Phone: 262-432-0350. E-mail: info@tmj.org.
This website is for general informational purposes only. It does not constitute professional medical advice, diagnosis, or treatment. This website is not a substitute for such advice, diagnosis, or treatment. You should always consult your doctor if you have questions about your health condition or before starting any treatment. The TMJA is unable to provide doctor referrals and does not endorse any particular health care professional or organization. Reliance on any information provided by TMJA, TMJA employees, others appearing on the website at the invitation of TMJA, or other visitors to the website is solely at your own risk.
Site Designed and Developed by 11th Hour Solutions, LLC