Temporomandibular joint involvement in generalized osteoarthritis and rheumatoid arthritis: a clinical, arthroscopic, histologic, and immunohistochemical study

Associations of inflammatory polyarthritis with clinical and radiological findings of temporomandibular disorders

OBJECTIVE

To evaluate the association of different forms of inflammatory polyarthritis with clinical signs of temporomandibular disorders (TMD) and radiological findings in temporomandibular joint (TMJ), based on a nationwide health survey in Finland. The aim was also to assess the presence of clinical and radiological TMD findings in subjects with increased risk for developing rheumatoid arthritis (RA).

MATERIAL AND METHODS

Anationally representative sample included 6331 Finnish adults who participated in the Health 2000 Survey (BRIF8901). Subjects were examined for signs of TMD, findings in panoramic radiograph of TMJ, musculoskeletal health and serology (rheumatoid factor, RF, and anti-cyclic citrullinated peptide, aCCP).

RESULTS

Sixty-four percent of seronegative RAand 60% of seropositive RAsubjects had at least one sign of TMD. While adjusting for confounding factors (gender, age, dentures and smoking history), RAwas significantly associated with crepitation and abnormal radiological findings in TMJ. Seronegative RAwas also associated with restricted mouth opening. Systemic autoimmunity associated with RA("at risk of RA") was not associated with clinical or radiological TMD findings.

CONCLUSIONS

Clinical and radiological findings of TMD are more prevalent among subjects with inflammatory polyarthritis than among the population in general in the Finnish adult population.

Otological symptoms in patients with rheumatoid arthritis of the temporomandibular joint

OBJECTIVE

The aim of the current study was to describe the pattern of otological symptoms in patients with rheumatoid arthritis (RA), having clinical temporomandibular joint (TMJ) involvement. This issue had not been previously addressed.

METHODS

A questionnaire and examination findings protocol was applied for 141 patients with RA and 141 control subjects.

RESULTS

Otological symptoms (otalgia, hearing loss, tinnitus, and vertigo), all had a significantly higher incidence in RA patients, compared to control subjects (P = .001).

CONCLUSION

The onset and maintenance of otological symptoms in patients with TMJ involvement by RA probably result from peripheral, as well as central nervous system alterations in sensory stimuli programming.

Temporomandibular disorders in immune-mediated rheumatic diseases of the adult: A systematic review

OBJECTIVE

To systematically review the literature concerning temporomandibular disorders (TMDs) in immune-mediated rheumatic diseases (IMRDs) of the adult. The temporomandibular joint (TMJ) outcomes used in clinical studies, the prevalence of TMDs in IMRDs and the risk factors for their development were qualitatively synthetized.

METHODS

A literature search on PubMed Central, Embase and Cochrane Library databases was performed for studies including TMJ outcomes in IMRDs patients compared with healthy controls, other rheumatic diseases or in the assessed IMRDs patients after follow-up and treatment. Among the IMRDs of the adult, original articles investigating TMJ involvement in inflammatory polyarthritides and/or autoimmune connective tissue diseases were considered. The quality of the studies was scored using the Newcastle-Ottawa scale (NOS).

RESULTS

Of the 3259 screened abstracts, 56 papers were included in the systematic review. Most of the papers (77%) investigated TMDs in rheumatoid arthritis (RA) with a prevalence of signs and symptoms varying from 8% to 70%. The risk factors for TMDs development in RA were female sex, younger age, anti-citrulline peptide autoantibodies (ACPA) positivity, higher disease activity, cervical spine involvement, cardiovascular and neuropsychiatric comorbidities. Ten papers (18%) evaluated TMDs in spondylarthritides (SpA) reporting a prevalence of symptoms and signs in 12%-80% of patients with higher TMDs prevalence in patients with radiographic spine involvement, skin psoriasis and HLADRB1×01 positivity. Among autoimmune connective tissue diseases (CTDs), systemic sclerosis (SSc) displayed the highest evidence of TMDs patient-reported outcomes (PROs) and clinical findings (20-93%), followed by systemic lupus erythematosus (SLE) in 18-85%, primary Sjogren's syndrome (24-54%) and idiopathic inflammatory myopathies (4-26%). In SSc and SLE, TMDs were more frequent in patients with higher disease activity and duration, correlating with the extent of skin fibrosis in SSc and with renal involvement in SLE.

CONCLUSION

TMDs in IMRDs display a significant relevance in the rheumatological clinical practice even if often misdiagnosed. This burden is epidemiologically important in terms of PROs and clinical findings which correlate with disease activity in RA, SpA, SSc and SLE. The early recognition and multidisciplinary management of TMDs is warranted and should be aimed at hindering the TMJ structural damage maximizing the quality of life of patients.

The Emerging Role of MMP12 in the Oral Environment

Matrix metalloproteinase-12 (MMP12), or macrophage metalloelastase, plays important roles in extracellular matrix (ECM) component degradation. Recent reports show MMP12 has been implicated in the pathogenesis of periodontal diseases. To date, this review represents the latest comprehensive overview of MMP12 in various oral diseases, such as periodontitis, temporomandibular joint dysfunction (TMD), orthodontic tooth movement (OTM), and oral squamous cell carcinoma (OSCC). Furthermore, the current knowledge regarding the distribution of MMP12 in different tissues is also illustrated in this review. Studies have implicated the association of MMP12 expression with the pathogenesis of several representative oral diseases, including periodontitis, TMD, OSCC, OTM, and bone remodelling. Although there may be a potential role of MMP12 in oral diseases, the exact pathophysiological role of MMP12 remains to be elucidated. Understanding the cellular and molecular biology of MMP12 is essential, as MMP12 could be a potential target for developing therapeutic strategies targeting inflammatory and immunologically related oral diseases.

Cytokines in temporomandibular joint synovial fluid and tissue in relation to inflammation

BACKGROUND

Synovial tissue is known to be the origin of inflammation in joint disease. Despite this, synovial fluid is the main biological specimen of choice in temporomandibular joint (TMJ) inflammation and pathology biomarker research. No comparison of TMJ protein content between synovial fluid and synovial tissue has been made.

OBJECTIVES

To investigate if cytokine concentrations in synovial fluid can be related to cytokine concentrations in synovial tissue, and to analyse correlation of clinical parameters reflecting local inflammation to cytokine concentrations.

METHODS

Synovial tissue and fluid samples were obtained during the same surgical procedure from a cohort of 101 patients with TMJ disorders. Interleukin (IL) 1β, IL-6, IL-8, IL-10, and tumor necrosis factor α (TNF-α) were analysed in the samples and an intraindividual correlation made. Various patient-specific factors relating to TMJ inflammation were associated to the cytokine concentrations in synovial fluid and tissue.

RESULTS

No correlation between cytokine concentration in synovial fluid and synovial tissue was found, except for IL-8 (ρ=.284, P=.024). Synovial tissue cytokines correlated strongly to inflammation-related factors: diagnosis (IL-1β, P=.001; TNF-α, P=.000; IL-10, P=.000), TMJ palpation pain (IL-1β, P=.024; TNF-α, P=.025), synovitis score (IL-1β, P=.015), and subjective TMJ pain (TNF-α, P=.016). Synovial fluid cytokines showed no significant relations to inflammation.

CONCLUSIONS

The investigated cytokine concentrations showed weak correlations between synovial fluid and synovial tissue, besides IL-8. Synovial tissue appeared to reflect inflammation to a higher extent than synovial fluid. Thus, suggesting that synovial tissue research should complement synovial fluid in future explorations of TMJ pathology and inflammation.

Proinflammatory cytokines levels in patients with temporomandibular joint disorder undergoing arthroscopy

PURPOSE

Biomarkers represent objective indicators of normal processes, pathology, or responses to therapeutic intervention. The purpose of this study is to evaluate the levels of proinflammatory cytokines in synovial fluid of the temporomandibular joint (TMJ) and to investigate whether there is a correlation between elevated levels and disease progression.

MATERIALS AND METHODS

This is a prospective study that included patients who were diagnosed with internal derangement according to magnetic resonance imaging and were classified according to Wilkes's classifications. After failing to improve with conservative treatment, they were referred for TMJ arthroscopy. During arthroscopy, synovial fluid was collected for biomarker analyses that included the investigation of levels of proinflammatory cytokines: tumor necrosis factor (TNF-α), interleukin 6 (IL-6), and vascular endothelial growth factor (VEGF). The Mann-Whitney U test was used for differences between subgroups for TNF-α, IL-6, and VEGF.

RESULTS

During the study period, 22 patients presented with a TMJ disorder and met the criteria of the study. There was a statistically significant correlation between the levels of VEGF, TNF-a, and osteoarthritis (P < 0.05). There was also a statistically significant correlation between TNF-a levels and a higher degree of chondromalacia (P = 0.019).

CONCLUSION

An increase in inflammatory cytokines coupled with chondromalacia propose a more aggressive degenerative disease.

Bidirectional relationship between temporomandibular disorder and ankylosing spondylitis: a population-based cohort study

OBJECTIVES

This study aimed to determine the relation between temporomandibular disorder (TMD) and ankylosing spondylitis (AS) bidirectionally and ascertain the important comorbidities for AS occurrence in TMD patients.

MATERIALS AND METHODS

We conducted this population-based cohort study through Longitudinal Health Insurance Database, Taiwan. Study 1 investigated the risk of TMD in AS patients. Study 2 assessed the risk of AS in TMD patients.

RESULTS

In total, 3204 AS patients and 12,816 age-matched and gender-matched comparisons were enrolled in study 1. The TMD incidence in the AS cohort was 2.88-fold higher when compared with the comparisons (1.54 vs. 0.53 per 10,000 person-years). After adjusting for age, gender, and comorbidity, the AS cohort had a 2.66-fold (95% CI = 1.79-3.97) increased risk of TMD occurrence (P < 0.0001). The second study recruited 4998 TMD patients and 19,991 age-matched and gender-matched comparisons. Both TMD and comparison cohorts showed similar AS risk (HR = 1.49, 95% CI = 0.91-2.43, P = 0.1108) in the adjusted model. Study 2 identified a 3.66-fold increased risk of AS occurrence in TMD patients with comorbidity, including parapsoriasis, rheumatoid arthritis, osteoporosis, Cushing's syndrome, and climacteric arthritis (P < 0.012).

CONCLUSIONS

AS appears to significantly impact the occurrence of TMD. TMD might play a synergic role in AS development.

CLINICAL RELEVANCE

Clinicians have to be vigilant about the increased risk of TMD in AS patients and take care of AS disease activity and prognosis. The symptoms and signs of TMD could be a predictor of AS in patients with the aforementioned comorbidities.

Relations between anterior disc displacement and maxillomandibular morphology in skeletal anterior open bite with changes to the mandibular condyle

In this study we investigated the relation between anterior disc displacement (ADD) and maxillomandibular morphology in skeletal anterior open bite with changes to the mandibular condyle. Thirty female patients (60 joints) with both conditions were evaluated. Magnetic resonance imaging of the temporomandibular joint (TMJ) was used to diagnose both ADD and changes to the mandibular condyle (erosion, osteophyte, and deformity). The relations among ADD, changes to the mandibular condyle, and maxillomandibular morphology were examined statistically. Changes to the mandibular condyle had a higher score than sym anterior open bite, the deviated side in asymmetric anterior open bite, and the non-deviated side. The score for disc displacement on the non-deviated side was lower than both the sym side and the deviated side. Unilateral changes to the mandibular condyle and unilateral disc displacement were not apparent in sym anterior open bite, but a unilateral non-displaced disc was seen only on the asymmetric side. Mandibular condylar changes were significantly more common on the deviated, than on the non-deviated, side. The SNB angle was significantly smaller, and the ANB, GZN, and SN-mandibular plane angles were significantly larger in sym anterior open bite. Overjet, ANB angle, GZN angle, and SN-MP angle were significantly larger, and the SNB angle was significantly smaller, in the presence of ADD without reduction and mandibular condylar deformity. We conclude that the prevalence of ADD without reduction and changes to the mandibular condyle were related to mandibular asymmetry and mandibular morphology in anterior open bite. This retrospective study suggests that ADD without reduction and mandibular condylar bone changes may be related to the progression of skeletal class II open bite and mandibular asymmetry in cases of skeletal open bite.

Crosstalk between Fas and S1P1 signaling via NF-kB in osteoclasts controls bone destruction in the TMJ due to rheumatoid arthritis

Rheumatoid arthritis (RA) mainly affects various joints of the body, including the temporomandibular joint (TMJ), and it involves an infiltration of autoantibodies and inflammatory leukocytes into articular tissues and the synovium. Initially, the synovial lining tissue becomes engaged with several kinds of infiltrating cells, including osteoclasts, macrophages, lymphocytes, and plasma cells. Eventually, bone degradation occurs. In order to elucidate the best therapy for RA, a comprehensive study of RA pathogenesis needs to be completed. In this article, we discuss a Fas-deficient condition which develops into RA, with an emphasis on the role of sphingosine 1-phosphate (S1P)/S1P receptor 1 signaling which induces the migration of osteoclast precursor cells. We describe that Fas/S1P₁ signaling via NF-κB activation in osteoclasts is a key factor in TMJ-RA severity and we discuss a strategy for blocking nuclear translocation of the p50 NF-κB subunit as a potential therapy for attenuating osteoclastogenesis.

Differential regulation by IFN‑γ on TNF‑α‑induced chemokine expression in synovial fibroblasts from temporomandibular joint

Tumor necrosis factor (TNF)‑α and interferon (IFN)‑γ, are inflammatory cytokines in the synovial fluid of patients with temporomandibular joint disorder (TMD). However, it remains unknown whether they participate in the regulation of various chemokine expression levels associated with TMD. The effects of TNF‑α and IFN‑γ on the expression of several different inflammatory chemokines, including interleukin (IL)‑8, C‑X‑C motif chemokine ligand (CXCL)1, C‑C motif chemokine ligand (CCL)20, CXCL9, CXCL10, and CXCL11 in synovial fibroblasts obtained from the temporomandibular joint (TMJ) were examined. The results demonstrated that TNF‑α increased the mRNA levels of all examined chemokines in synovial fibroblasts obtained from the TMJ. IFN‑γ treatment alone increased the mRNA expression levels of CXCR3 chemokines, including CXCL10, while they were significantly enhanced when administered in combination with TNF‑α compared with either treatment alone. However, the combination of IFN‑γ and TNF‑α resulted in lower mRNA expression levels of IL‑8 and CXCL1 as compared with those induced by TNF‑α alone. The nuclear factor‑κB inhibitor, Bay 11‑7082, decreased the TNF‑α‑mediated expression of IL‑8 and CXCL10 in the absence, and presence of IFN‑γ. In addition, the JAK2 inhibitor, AG490, decreased CXCL10 expression when administered with TNF‑α and IFN‑γ. Finally, the decrease in TNF‑α‑induced IL‑8 caused by IFN‑γ was recovered by AG490. The results of the present study suggest that TNF‑α and IFN‑γ function in a cooperative manner to regulate inflammatory chemokine expression in synovial fibroblasts, which may contribute to the pathological condition of the TMJ.

Elastin‑derived peptides are involved in the processes of human temporomandibular disorder by inducing inflammatory responses in synovial cells

Temporomandibular joint dysfunction (TMD) is a collection of clinical symptoms that involve masticatory muscles and the temporomandibular joint (TMJ). Common symptoms include limited jaw motion and joint sound/pain, along with TMJ disc displacement. TMD is frequently associated with synovitis, a chronic inflammation of the synovium. Fibroblast-like synovial cells have been identified to produce several inflammatory mediators and may have an important role in the progression of TMJ inflammation. Degradation of the extracellular matrix molecule elastin may lead to the release of bioactive peptides. The present study aimed to explore the role of elastin-derived peptides (EDPs) in human temporomandibular disorders. Therefore, interleukin-6 (IL-6) expression in the synovial fluid obtained from patients with TMD correlated significantly with two clinical parameters, specifically TMJ locking and pain/jaw function on a visual analog scale (VAS). To the best of our knowledge, this is the first study to determine that the concentration of EDPs in synovial fluid from patients with TMD may also be significantly correlated with the duration of TMJ locking, the VAS score and IL-6 expression. In vitro, EDPs act on human TMJ synovial cells to promote upregulation of IL-6 and the elastin-degrading enzyme matrix metalloproteinase-12 (MMP-12). The upregulation of IL-6 and MMP-12 expression by EDPs may be mediated through elastin-binding proteins (EBP) and a protein kinase A signalling cascade. These findings suggest a model for inflammation in the TMJ where EDPs are generated by harmful mechanical stimuli, induce both a pro-inflammatory cascade and increase expression of MMP-12 through activation of the EBP signalling cascade. This may lead to further increases in EDP levels, establishing a positive feedback loop leading to chronic inflammation in the TMJ. Therefore, significantly elevated levels of EDPs and IL-6 in the synovial fluid of the TMJ may be indicators of the pathological conditions of the joint.

Gene Expression Profiling of IL-17A-Treated Synovial Fibroblasts from the Human Temporomandibular Joint

Synovial fibroblasts contribute to the inflammatory temporomandibular joint under pathogenic stimuli. Synovial fibroblasts and T cells participate in the perpetuation of joint inflammation in a mutual activation feedback, via secretion of cytokines and chemokines that stimulate each other. IL-17 is an inflammatory cytokine produced primarily by Th17 cells which plays critical role in the pathogenesis of numerous autoimmune and inflammatory diseases. Here, we investigated the roles of IL-17A in temporomandibular joint disorders (TMD) using genome-wide analysis of synovial fibroblasts isolated from patients with TMD. IL-17 receptors were expressed in synovial fibroblasts as assessed using real-time PCR. Microarray analysis indicated that IL-17A treatment of synovial fibroblasts upregulated the expression of IL-6 and chemokines. Real-time PCR analysis showed that the gene expression of IL-6, CXCL1, IL-8, and CCL20 was significantly higher in IL-17A-treated synovial fibroblasts compared to nontreated controls. IL-6 protein production was increased by IL-17A in a time- and a dose-dependent manner. Additionally, IL-17A simulated IL-6 protein production in synovial fibroblasts samples isolated from three patients. Furthermore, signal inhibitor experiments indicated that IL-17-mediated induction of IL-6 was transduced via activation of NFκB and phosphatidylinositol 3-kinase/Akt. These results suggest that IL-17A is associated with the inflammatory progression of TMD.

Implications for eicosapentaenoic acid- and docosahexaenoic acid-derived resolvins as therapeutics for arthritis

Omega-3 polyunsaturated fatty acids are essential for health and are known to possess anti-inflammatory properties, improving cardiovascular health as well as benefiting inflammatory diseases. Indeed, dietary supplementation with omega-3 polyunsaturated fatty acids has proved efficacious in reducing joint pain, morning stiffness and nonsteroidal anti-inflammatory drugs usage in rheumatoid arthritis patients. However, the mechanisms by which omega-3 polyunsaturated fatty acids exert their beneficial effects have not been fully explored. Seminal discoveries by Serhan and colleagues have unveiled a novel class of bioactive lipid mediators that are enzymatically biosynthesized in vivo from omega-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), termed resolvins, protectins and maresins. These bioactive pro-resolving lipid mediators provide further rationale for the beneficial effects of fish-oil enriched diets. These endogenous lipid mediators are spatiotemporally biosynthesized to actively regulate resolution by acting on specific G protein-coupled receptors (GPCRs) to initiate anti-inflammatory and pro-resolving signals that terminate inflammation. In this review, we will discuss the mechanism of actions of these molecules, including their analgesic and bone-sparing properties making them ideal therapeutic agonists for the treatment of inflammatory diseases such as rheumatoid arthritis.

Lubricin protects the temporomandibular joint surfaces from degeneration

The temporomandibular joint (TMJ) is a specialized synovial joint essential for the mobility and function of the mammalian jaw. The TMJ is composed of the mandibular condyle, the glenoid fossa of the temporal bone, and a fibrocartilagenous disc interposed between these bones. A fibrous capsule, lined on the luminal surface by the synovial membrane, links these bones and retains synovial fluid within the cavity. The major component of synovial fluid is lubricin, a glycoprotein encoded by the gene proteoglycan 4 (Prg4), which is synthesized by chondrocytes at the surface of the articular cartilage and by synovial lining cells. We previously showed that in the knee joint, Prg4 is crucial for maintenance of cartilage surfaces and for regulating proliferation of the intimal cells in the synovium. Consequently, the objective of this study was to determine the role of lubricin in the maintenance of the TMJ. We found that mice lacking lubricin have a normal TMJ at birth, but develop degeneration resembling TMJ osteoarthritis by 2 months, increasing in severity over time. Disease progression in Prg4^−/− mice results in synovial hyperplasia, deterioration of cartilage in the condyle, disc and fossa with an increase in chondrocyte number and their redistribution in clusters with loss of superficial zone chondrocytes. All articular surfaces of the joint had a prominent layer of protein deposition. Compared to the knee joint, the osteoarthritis-like phenotype was more severe and manifested earlier in the TMJ. Taken together, the lack of lubricin in the TMJ causes osteoarthritis-like degeneration that affects the articular cartilage as well as the integrity of multiple joint tissues. Our results provide the first molecular evidence of the role of lubricin in the TMJ and suggest that Prg4^−/− mice might provide a valuable new animal model for the study of the early events of TMJ osteoarthritis.

Evaluation of the TMJ by means of clinical TMD examination and MRI diagnostics in patients with rheumatoid arthritis

This study included 30 patients with diagnosed rheumatoid arthritis (RA) and 30 test subjects without RA (control group). The objective of the study was to examine both groups for the presence of temporomandibular disorders (TMD) and morphological changes of the temporomandibular joint (TMJ). All individuals were examined using a systematic detailed clinical TMD examination as well as magnetic resonance imaging (MRI). The clinical TMD examination yielded significant differences between the RA patients and the control group concerning crepitus of the TMJ, and palpation tenderness of the masticatory muscles as well as the unassisted mandibular opening. The evaluation of the MRI images for the RA group showed significantly more frequent deformations of the condyle, osteophyte formations and erosions in the condylar compacta, and degenerative changes in the spongiosa. Increased intra-articular accumulation of synovial liquid and signs of inflammatory changes of the spongiosa were only found in the RA group. Statistical analysis showed a significant correlation between crepitus and specific osteoarthrotic changes (MRI), respectively, and between crepitus and a complete anterior disk displacement without reduction (MRI). The duration of the RA disease correlated neither with the anamnestic and clinical dysfunction index by Helkimo nor with RA-specific MRI findings.

Effect of surgical repair of the joint capsule in mandibular condyle fractures in adult rats

PURPOSE

The aim of the present study was to assess histologic changes in the temporomandibular joint (TMJ) of adult rats subjected to unilateral fracture of the mandibular condyle and soft tissue injury.

MATERIALS AND METHODS

The animals were divided into 2 groups: one had surgical treatment for soft tissue repair and the other had no soft tissue treatment. All histologic evaluations were performed according to the presence or absence of synovitis, vascularity, presence or absence of joint inflammation, and presence or absence of the articular disc. The contralateral TMJs also were evaluated.

RESULTS

The results showed few histologic changes in the synovial membrane and joint disc for the 2 groups and in the synovial membrane and disc of the contralateral side, where indirect trauma occurred in the unoperated joint.

CONCLUSION

This study showed that treating or not treating soft tissues does not change the treatment results of condyle fracture or interfere with TMJ pathosis.

The role of omega-3 derived resolvins in arthritis

Omega-3 polyunsaturated fatty acids (PUFAs) are known to alleviate joint stiffness and pain in rheumatoid arthritis patients. However, the mechanisms by which omega-3s exert their beneficial effects has not been fully explored. Herein we discuss a novel class of bioactive lipid mediators, which are enzymatically biosynthesized in vivo from omega-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), termed resolvins. These lipid mediators exert anti-inflammatory and pro-resolving properties and are log-orders more potent than their precursors. We also highlight that formation of pro-resolving mediators can be enhanced by widely used anti-inflammatory and cardioprotective drugs (aspirin and statins) via the modification of cyclooxygenase-2 enzymatic activity. These bioactive pro-resolving lipid mediators provide further rationale for the beneficial effects of dietary supplementation with fish oils, and offer new avenues for developing therapeutics for inflammatory conditions such as rheumatoid arthritis.

Effects of interleukin-1β and tumor necrosis factor-α on macrophage inflammatory protein-3α production in synovial fibroblast-like cells from human temporomandibular joints

Background

Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) are key mediators of the intracapsular pathological conditions of the temporomandibular joint (TMJ). Therefore, the gene expression profiles in synovial fibroblast-like cells (SFCs) from patients with internal derangement of the TMJ were examined after they were stimulated with IL-1β or TNF-α to determine which genes were altered.

Methods

Ribonucleic acid was isolated from SFCs after IL-1β or TNF-α treatment. Gene expression profiling was performed using oligonucleotide microarray analysis. On the basis of the results of this assay, we investigated the kinetics of macrophage inflammatory protein-3α (MIP-3α) gene expression using PCR, and protein production in TMJ SFCs stimulated by IL-1β or TNF-α using an ELISA. Inhibition experiments were performed with MAPK and NFκB inhibitors. SFCs were stimulated with IL-1β or TNF-α after treatment with inhibitors. The MIP-3α levels were measured using an ELISA.

Results

Macrophage inflammatory protein-3α was the gene most upregulated by IL-1β- or TNF-α stimulation. The mRNA and protein levels of MIP-3α increased in response to IL-1β in a time-dependent manner. In contrast, during TNF-α stimulation, the MIP-3α mRNA levels peaked at 4 h, and the protein levels peaked at 8 h. In addition, the IL-1β- and TNF-α-stimulated MIP-3α production was potently reduced by the MAPK and NFκB signaling pathway inhibitors.

Conclusion

Interleukin-1β and TNF-α increased the MIP-3α production in SFCs via the MAPK and NFκB pathways. These results suggest that the production of MIP-3α from stimulation with IL-1β or TNF-α is one factor associated with the inflammatory progression of the internal derangement of the TMJ.

Clinical and magnetic resonance imaging findings of the temporomandibular joint in patients with rheumatoid arthritis

Background

The aim of this study is to evaluate temporomandibular joint (TMJ) involvement in patients with rheumatoid arthritis by magnetic resonance imaging (MRI), jaw clenching force, mouth opening, and Fonseca’s questionnaire, and to establish the relationship between these findings and clinical, radiologic, and laboratory activity parameters that are unique to rheumatoid arthritis.

Methods

Included in the study were 30 RA patients and 30 healthy volunteers. Jaw clenching force of the entire cases was measured with Istanbul Bite Force Recorder (kg) and the mouth opening was measured with a ruler (cm). Additionally, hand grip forces of patients with rheumatoid arthritis were measured with hand dynamometer (kg). Hand and feet graphs and TMJ MRIs of patients were obtained. MRI findings were classified as normal, mild, medium, and severe. DAS28 and sharp scores of patients were estimated. Sedimentation rate (ESR), C-Reactive protein (CRP) and rheumatoid factor (RF) were checked in the patient group and Fonseca’s questionnaires were filled in.

Results

A significant difference was not observed between age, gender, and level of education of the groups. Jaw clenching force and mouth opening were established as significantly low in RA group compared to the control group (P < 0.001). A significant correlation was found between jaw clenching force, hand grip force, mouth opening, questionnaire, and MRI findings with the disease duration sharp score, DAS28, and hand grip force of the RA group (P < 0.05). However, a significant correlation was not established with ESR, CRP, and RF (P < 0.001).

Conclusions

Jaw clenching force, mouth opening, and Fonseca’s questionnaire can be used as parameters pointing to TMJ involvement in patients with RA. Yet, further studies in which TMJ involvement is followed up since the onset of the disease are of necessity.

Magnetic resonance imaging of the temporomandibular joint in the rat compared with low-powered light microscopy

OBJECTIVE

High magnetic field magnetic resonance imaging (MRI) was applied to the temporomandibular joint (TMJ) in the rat. The purpose of this study was the depiction of the internal structure of the TMJ, including the articular disc, articular cartilage, and the upper and lower joint cavities. We also proposed MRI settings and slices suitable for imaging the TMJ in the rat.

METHODS

Temporomandibular joints from one female and eight male Sprague Dawley rats (5-8 weeks old) and four male Wistar-Hamamatsu rats (7-8 weeks old) were used. Using scout images, the horizontal plane was defined as being parallel to the body of the basisphenoid bone underneath the base of the brain. The coronal plane was defined as a slice vertical to the horizontal plane and vertical to the longitudinal fissure of the cerebrum. The sagittal plane was defined as a slice vertical to the horizontal plane and parallel to the longitudinal fissure of the cerebrum.

RESULTS

T(1)-weighted MR images with a spatial resolution of 75 μm were obtained for 5 min. The temporal bone and mandibular condyle were depicted as lower signal intensity images and the articular disc was depicted as an intermediate signal intensity image. In accordance with Gd-DTPA-enhanced MR or T(2)-weighted MR images, the articular disc, articular cartilage, and the upper and lower joint cavities could be assigned clearly.

CONCLUSION

These MRI findings closely agreed with those observed with haematoxylin-eosin staining under light microscopy, suggesting that MRI is a useful method for analyzing the complex structure of the TMJ in the rat.

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.

Osteoarthritis-like damage of cartilage in the temporomandibular joints in mice with autoimmune inflammatory arthritis

OBJECTIVE

To study temporomandibular joint (TMJ) involvement in an autoimmune murine model of rheumatoid arthritis (RA), a disease characterized by inflammatory destruction of the synovial joints. Although TMJ dysfunction is frequently found in RA, TMJ involvement in RA remains unclear, and TMJ pathology has not been studied in systemic autoimmune animal models of RA.

METHODS

Proteoglycan (PG) aggrecan-induced arthritis (PGIA) was generated in genetically susceptible BALB/c mice. TMJs and joint tissues/cartilage were harvested for histological and immunohistochemical analyses and RNA isolation for quantitative polymerase chain-reaction. Serum cytokine levels were measured in mice with acute or chronic arthritis, and in non-arthritic control animals.

RESULTS

Despite the development of destructive synovitis in the limbs, little or no synovial inflammation was found in the TMJs of mice with PGIA. However, the TMJs of arthritic mice showed evidence of aggrecanase- and matrix metalloproteinase-mediated loss of glycosaminoglycan-containing aggrecan, and in the most severe cases, structural damage of cartilage. Serum levels of pro-inflammatory cytokines, including interleukin (IL)-1β, were elevated in arthritic animals. Expression of the IL-1β gene was also high in the inflamed limbs, but essentially normal in the TMJs. Local expression of genes encoding matrix-degrading enzymes (aggrecanases and stromelysin) was upregulated to a similar degree in both the limbs and the TMJs.

CONCLUSION

We propose that constantly elevated levels of catabolic cytokines, such as IL-1β, in the circulation (released from inflamed joints) create a pro-inflammatory milieu within the TMJ, causing local upregulation of proteolytic enzymes and subsequent loss of aggrecan from cartilage.

Relationships between pathology and pain severities: a review

The relationships between pathology severity and pain severity are reviewed using the literature available for humans. The aim is to help veterinary radiologists, physicians and pathologists recognise the disorders in which severity of a lesion is likely to be related to the severity of pain or to incipient pain. Specific features or lesions within the following conditions showed a relationship with pain score, which was usually assessed with a visual analogue scale: inflammation; pancreatitis; ileitis; mucositis; fasciitis; synovitis; arthritis; lower back pain; disc herniation; sciatica; scoliosis; myalgia; cancer; arteriosclerosis; skin ulcers; mastalgia; skin and oral neuropathies; endometriosis; hepatopathy and chronic pulp diseases of the teeth. As experience with magnetic resonance imaging grows, there will be further opportunities to look for quantitative relationships in humans between pathology and pain severities. This information will be useful to veterinarians and other people working with animals in evaluating pain in animals in their care.

Evaluation of arthroscopy and macroscopic scoring

INTRODUCTION

Arthroscopy is a minimally invasive technique for retrieving synovial biopsies in rheumatology during the past 20 years. Vital for its use is continual evaluation of its safety and efficacy. Important for sampling is the fact of intraarticular variation for synovial markers. For microscopic measurements scoring systems have been developed and validated, but for macroscopic evaluations there is a need for further comprehensive description and validation of equivalent scoring systems.

METHODS

We studied the complication rate and yield of arthroscopies performed at our clinic between 1998 and 2005. We also created and evaluated a macroscopic score set of instructions for synovitis.

RESULTS

Of 408 procedures, we had two major and one minor complication; two haemarthrosis and one wound infection, respectively. Pain was most often not a problem, but 12 procedures had to be prematurely ended due to pain. Yield of biopsies adequate for histology were 83% over all, 94% for knee joints and 34% for smaller joints. Video printer photographs of synovium taken during arthroscopy were jointly and individually reviewed by seven raters in several settings, and intra and inter rater variation was calculated. A macroscopic synovial scoring system for arthroscopy was created (Macro-score), based upon hypertrophy, vascularity and global synovitis. These written instructions were evaluated by five control-raters, and when evaluated individual parameters were without greater intra or inter rater variability, indicating that the score is reliable and easy to use.

CONCLUSIONS

In our hands rheumatologic arthroscopy is a safe method with very few complications. For knee joints it is a reliable method to retrieve representative tissue in clinical longitudinal studies. We also created an easy to use macroscopic score, that needs to be validated against other methodologies. We hope it will be of value in further developing international standards in this area.

Expression of cyclooxygenase-1 and -2 in IL-1beta-induced synovitis of the temporomandibular joint

BACKGROUND

In this study, we analyzed the gene expression profile of fibroblast-like synoviocyte (FLS) cultures from the temporomandibular joint (TMJ) to identify candidate genes associated with intracapsular pathologic conditions of TMJ. Cyclooxygenase (COX)-2 was one of the genes in FLS upregulated following stimulation by interleukin (IL)-1beta, a cytokine thought to play a key role in several pathological conditions. This study investigated the expression of COX-1 and COX-2 in cultured human FLS and rat TMJ synovium following stimulation with IL-1beta.

METHODS

RNA was isolated from human FLS after IL-1beta treatment. COX-1 and -2 expression was examined using a GeneChip and real-time polymerase chain reaction. Prostaglandin E(2) (PGE(2)) levels in conditioned media from FLS were measured using enzyme-linked immunosorbent assay. Synovial tissues from TMJs of IL-1beta-injected rats were examined for COX-1 and COX-2 expression by immunohistochemical staining.

RESULTS

Following treatment of FLS with IL-1beta, expression of the COX-2 gene increased up to 8 h and peaked at 4 h, whereas COX-1 expression did not change. Stimulation with IL-1beta increased the level of PGE(2) in conditioned media of cultured FLS in a time-dependent manner up to 48 h. Immunohistochemistry showed a strong positive staining for COX-2 in the lining and sub-lining synovial tissues of the TMJ of IL-1beta-injected rats. In contrast, staining for COX-1 was the same in synovial tissues with and without IL-1beta injection.

CONCLUSION

These data suggest that COX-2 expression stimulated by IL-1beta stimulates the production of PGE(2) in FLS and plays important roles in the progression of inflammation in TMJ.

Targeted assessment of the temporomandibular joint in patients with rheumatoid arthritis

PURPOSE

This observational study was done to identify the signs and symptoms of temporomandibular joint (TMJ) involvement in patients with rheumatoid arthritis (RA) and to assess the association between these and quantitative measurements for the evaluation of rheumatologic disease.

PATIENTS AND METHODS

The sample comprised 61 patients suffering from RA whose signs and symptoms of TMJ were recorded by means of a questionnaire (scale of limited mandibular function) and clinical measurements (pain during jaw movement, limitation of maximal mouth opening, joint sounds, tenderness on TMJ palpation, tenderness on masticatory muscle palpation). These findings were correlated with the quantitative measurements for evaluating RA: duration of the disease, positivity for rheumatoid factor, Health Assessment Questionnaire (HAQ) score, number of edematous and painful joints, and overall assessment of functional status.

RESULTS

In terms of overall figures, 70.5% of the patients presented with at least 1 sign or symptom, 49.2% had at least 1 symptom, and 54.1% had at least 1 sign. The variable pain on movement was associated with the number of painful joints and the overall assessment findings (P < .05). Sound on movement was positively associated with the number of edematous joints (P = .0291). The scale of limited mandibular function was statistically significantly correlated with 4 quantitative measurements (P = .0283 to .0448). The variable pain on palpation of the masticatory muscles was associated with the number of painful joints (P = .0023). Pain on palpation of the TMJ was statistically significantly associated with the HAQ score (P = .0344) and with the number of painful joints (P = .0006).

CONCLUSION

A significant percentage of the patients with RA have signs and symptoms of TMJ involvement, and the scale of limited mandibular function proved to be an important measurement tool.

Histologic and histomorphometric analysis of posterior region of the human temporomandibular disc

OBJECTIVE

The aim of this study was to analyze histologic and histomorphometric features of the articular disc in groups with and without disc displacement.

STUDY DESIGN

A sample of 39 temporomandibular joints TMJs (31 case specimens, 8 control specimens) from 28 patients (mean age 31.2 years) were recruited for this study. The patients were considered to be affected and treated surgically with disc repositioning when presenting painful clinical signs of disc displacement after unsuccessful nonsurgical treatment for at least 6 months. Of the control patients, 4 presented condyle fracture which required opening to be reduced for treatment, and 4 displayed active condyle hyperplasia. The posterior region of the disc was removed and sent for histologic and histomorphometric analysis. Histologic (hematoxylin-eosin) and histomorphometric (picro-Sirius red) analyses were performed. Statistically significant differences between the analyzed groups were accessed through the chi-squared test (P <or= .05). The Mann-Whitney U test was used to observe the differences between mean values when variables did not present normal distribution [Kolmogorov-Smirnov(a) test].

RESULTS

There were no significant differences between the groups in relation to the parameters studied by histologic and histomorphometric analysis (using or not using polarization).

CONCLUSIONS

To the limits of this study, there were no significant histologic and histomorphometric differences in the articular disc between groups with and without TMJ dysfunction.

Temporomandibular joint disorders in patients with rheumatoid arthritis

BACKGROUND

Temporomandibular joint disorders (TMD) are not uncommon in patients with rheumatoid arthritis (RA). However, the extent of involvement and its clinical relevance have not been well characterized. This study evaluated the correlation between the severity of RA-related TMD and RA, as well as determined the potential predictors for early identification and management of TMD in RA patients.

METHODS

We sequentially recruited 56 adult RA patients from our Arthritis Clinic. TMD and RA were surveyed, clinically by questionnaires and physical examinations, and radiologically by tomography in TMD and conventional radiography in RA. The patients were stratified into no, mild and severe TMD groups according to the physical and tomographic examinations. The correlation of the severity of TMD and RA were evaluated. The relative importance of relevant predictors of severe TMD was analyzed by a logistic regression model.

RESULTS

Physical and radiologic temporomandibular joint abnormalities were found to be highly prevalent (85.7% and 74.5%) in these patients, and the occurrence increased to as much as 92.9% when the 2 data sets were combined. More than half of the patients had severe TMD presenting with debilitating symptoms or with a significant degree of bony destruction. The severity of TMD was variably correlated with RA severity. The score of hand-joint space narrowing was found to be the most influential predictor of severe TMD by logistic regression analysis.

CONCLUSION

There was a high prevalence of TMD in RA patients. The severity of TMD variably correlated with RA severity. Clinically, a high score of hand-joint space narrowing may serve as an early indicator of RA patients at risk of severe TMD. This may facilitate early management and prevent the functional impairment of the temporomandibular joint.

Microarray analysis of IL-1β-stimulated chemokine genes in synovial fibroblasts from human TMJ

BACKGROUND

Interleukin (IL)-1beta is thought to play a key role in several pathologic conditions of the temporomandibular joint (TMJ). Gene expression profile of synovial fibroblasts stimulated with IL-1beta was studied by oligonucleotide microarray analysis to elucidate candidate genes associated with intracapsular pathologic conditions of TMJ.

METHODS

RNA was isolated from synovial fibroblasts from five patients after IL-1beta treatment. Gene expression profiling was performed with a GeneChip. Changes in gene expression were determined by comparing IL-1beta-treated cells with untreated cells.

RESULTS

A total of 121 genes showed a greater than threefold difference in average intensity between untreated and IL-1beta-treated synovial fibroblasts in five experiments. Five chemokines were among the 10 most upregulated genes, and the most upregulated gene was CCL20. The 121 IL-1beta-responsive genes included 12 chemokines whose mRNA levels were confirmed by real-time PCR.

CONCLUSION

These data should provided useful information about the pathologic conditions of TMJ, especially in support of diagnosis and therapeutic approaches to TMJ.

Sonographic investigation of the temporomandibular joint in patients with juvenile idiopathic arthritis: A pilot study

OBJECTIVE

To evaluate whether there are any correlations between the clinical parameters of temporomandibular joint (TMJ) arthritis and pathologic ultrasound (US) findings of the TMJ in patients with juvenile idiopathic arthritis (JIA).

METHODS

We conducted prospective clinical and US investigations of the TMJs of 48 patients with JIA. The US investigation was performed by a 12-MHz high-resolution transducer, which was positioned parallel to the ramus of the mandible overlying the zygomatic arch in a closed-mouth position and maximum open-mouth position.

RESULTS

Patients with > or = 5 peripheral affected joints showed significantly more sonographically diagnosed destructive changes in the TMJ than did patients with <5 affected joints. There was no significance between the number of affected peripheral joints and disc dislocation in the closed-mouth position. In the maximum open-mouth position, there was a significant correlation between the number of affected peripheral joints and disc dislocation. Patients with a JIA duration >23 months had a significantly higher rate of disc dislocation and destructive changes. Patients with a JIA duration >60 months had a significantly higher rate of destructive changes of the TMJ than patients with a disease duration <60 months, but no statistical significance was found concerning disc dislocation.

CONCLUSION

The significant correlation between pathologic sonographic findings, duration of JIA, and the number of affected peripheral joints make the technique interesting for use as a diagnostic screening method.

Inflammatory cell and cytokine patterns in patients with chronic polyarthritis and temporomandibular joint involvement

OBJECTIVE

To investigate the occurrence of selected markers for inflammatory cells and cytokines in patients with chronic polyarthritis (CPA) and temporomandibular joint (TMJ) involvement.

MATERIAL AND METHODS

Eleven patients (11 joints) with CPA and TMJ disorder were included in the study. Synovial specimens were obtained during TMJ open surgery and these were subjected to immunohistochemistry on frozen sections post-fixed with paraformaldehyde and with the cell membranes permeabilized by saponin. In all patients, the cytokines IL-1alpha, IL-1beta, IL-1ra, TNFalpha, IFNgamma, IL2, and TGFbeta were investigated using specific antibodies. The occurrence of macrophages and T-lymphocytes was investigated using immunohistochemistry with monoclonal antibodies against antigens CD68 and CD45RO, respectively. In addition, PCNA was used as a marker for cell proliferation.

RESULTS

Staining of IL-1alpha, IL-1, and TGF was seen in all 11 specimens, IFN? in 1, TNFalpha in 4, and IL-2 in none. CD45RO-positive T cells were detected in 7 specimens, CD68-positive macrophages in 6, and cell proliferation seen with PCNA was noted in 8.

CONCLUSIONS

The predominant cytokines of TMJ CPA were IL-1alpha, IL-1beta, and TGFbeta, and there appeared to be no differences between the subgroups (rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis) involved. Moreover, the cytokine pattern of TMJ CPA patients seemed to differ from patients with osteoarthritis, as shown in our previous study. The main difference was the absence of IFNgamma and TNFalpha in TMJ CPA patients and a stronger TGFbeta and IL-1alpha expression.

Tumor necrosis factor-alpha increases chemokine gene expression and production in synovial fibroblasts from human temporomandibular joint

BACKGROUND

Synovitis, which is characterized by infiltration of inflammatory cells, often accompanies progression of clinical symptoms of the temporomandibular joint (TMJ). Synovial fibroblasts of the TMJ are believed to play important roles in progression of synovitis. The purpose of this study was to examine production and gene expression of chemokines by synovial fibroblasts stimulated by tumor necrosis factor-alpha (TNF-alpha).

METHODS

Protein levels of chemokines were measured by enzyme-linked immunosorbent assay (ELISA). Gene expression of chemokines was analyzed by real-time polymerase chain reaction (PCR).

RESULTS

Production of interleukin (IL)-8, growth-related oncogene (GRO)-alpha, monocyte chemoattractant protein (MCP)-1, and regulated upon activation normal T-cell expressed and secreted (RANTES) protein by synovial fibroblasts was increased by TNF-alpha. In contrast, stromal cell-derived factor (SDF)-1alpha, macrophage inflammatory protein (MIP)-1alpha and -1beta were not detectable in conditioned media of synovial fibroblasts, with or without TNF-alpha treatment. Increases in gene expression of IL-8, GRO-alpha, MCP-1, and RANTES in response to TNF-alpha treatment were detected.

CONCLUSIONS

Increased protein production and gene expression of chemokines by synovial fibroblasts in response to TNF-alpha treatment appears to play an important role in recruitment of inflammatory cells into synovium and the progression of synovitis in the TMJ.

Pathology of the temporomandibular joint of patients with rheumatoid arthritis--case reports of secondary amyloidosis and macrophage populations

INTRODUCTION

The pathogenetic features of rheumatoid arthritis of the temporomandibular joint (TMJ) are not well defined. In this paper the histological features of TMJs affected by rheumatoid arthritis, and the detection of secondary amyloidosis and macrophage populations in the TMJs of two patients with progressive rheumatoid arthritis are described.

METHODS

In two patients (64-year-old man and 61-year-old woman) with rheumatoid arthritis total TMJ replacement were performed. The surgical specimens were studied histologically.

RESULTS

It was found that the articular cartilage had been completely replaced by proliferating fibrous tissue. Congo red staining and polarizing microscopy revealed amyloid deposition in the connective tissue of the joint space. Immunohistochemical staining showed CD 68 positive macrophages around the amyloid deposition in the proliferating soft tissue.

CONCLUSION

TMJ involvement in rheumatoid arthritis followed the same destructive pathway as in other joints. Amyloid deposition and macrophage populations were detected in two TMJs affected by rheumatoid arthritis.

Inflammatory cell and cytokine patterns in patients with painful clicking and osteoarthritis in the temporomandibular joint

The occurrence of a subset of cytokines and leukocytes in the posterior disc attachment area of the temporomandibular joint (TMJ) was investigated in two patient groups, i.e, one group with painful clicking and one with osteoarthritis. Synovial biopsies were taken during discectomy in 19 patients with painful clicking and 20 with osteoarthritis. One set of specimens was examined with immunohistochemistry, using frozen sections postfixed by para-formaldehyde and with the cell membranes permeablized in saponin. These sections were incubated with antibodies against cytokines IL-1alpha, IL-1beta, IL-1ra, TNFalpha, IFNgamma, IL2 in all patients and TGFbeta1,2,3 in 16. The other set of specimens was used to characterize cell infiltrates using immunohistochemistry with monoclonal antibodies against antigens CD68 and CD45RO, respectively. Moreover, PCNA was included as a marker for cell proliferation. The cytokine staining was most frequently positive for IL-1alpha and IL-1beta in both patient groups. However, joints with OA showed a more complex cytokine pattern, also involving IFN-gamma (P = 0.019), IL-ra (P = 0.047), and apparently but without reaching the chosen level of significance, IL-2, TNF-alpha and TGF-beta1,2,3. Positive staining for CD45RO was frequent in both groups. OA patients showed more frequently positive staining for CD68 (P = 0.025) and apparently for PCNA.

[Temporomandibular disorders in juvenile patients with rheumatic diseases]

PURPOSE

The aim of the study was to investigate the incidence of temporomandibular disorders (TMD) in juvenile patients with rheumatic diseases. Furthermore, correlations between the degree of the rheumatic disease and the clinical symptoms were evaluated.

MATERIAL AND METHODS

In a prospective investigation the temporomandibular joints of 48 children with rheumatic diseases were evaluated clinically regarding clicking, crepitation, pain, duration of the rheumatic disease, and the number of affected peripheral joints. The degree of rheumatic disease was assessed with Steinbrocker's classification.

RESULTS

26 patients (54.17%) showed clinical symptoms of TMD. No significant correlation was found between the degree of the rheumatic disease and the awareness of TMD. A high number of affected peripheral joints does not lead to a significant increase of TMD. A significant correlation between the duration of the rheumatic disease and TMD could be detected. A significant correlation between the duration of the rheumatic disease and clicking or crepitation was found ( p=0.011).

CONCLUSION

Rheumatic diseases lead to a higher incidence of TMD in juvenile patients. A longer duration of rheumatic diseases leads to a higher incidence of TMD.

Inducible nitric oxide synthase and apoptosis-related factors in the synovial tissues of temporomandibular joints with internal derangement and osteoarthritis

PURPOSE

In this study, we investigated the relationship between oxidative stress and apoptosis in synovial tissues in temporomandibular joint diseases (TMDs), including internal derangement (ID) and osteoarthritis (OA), comparing immunohistochemical, arthroscopic, and histologic findings.

MATERIALS AND METHODS

Synovial specimens obtained from patients with ID (31 patients), osteoarthritis (11 patients), and condylar fractures of the mandible (5 patients) during arthroscopy were examined immunohistochemically using antibodies against CD68, inducible nitric oxide synthase (iNOS), Fas, and single-stranded DNA (ssDNA).

RESULTS

CD68 and iNOS immunoreactivity were detected mainly in synovial lining cells and subintimal macrophages, and tended to increase with synovial hyperplasia. Fas and ssDNA immunoreactivity was detected mainly in synovial lining cells, and Fas-positive regions exhibited a number of ssDNA-positive cells. Fas expression was significantly greater in fractures than in OA, and ssDNA expression was significantly greater in OA than in ID. Fas expression was significantly greater in iNOS-positive versus iNOS-negative TMJs, and ssDNA expression tended to increase with iNOS expression.

CONCLUSION

These immunohistochemical findings suggest that oxidative stress and apoptosis in synovial tissues are involved in the onset and progression of TMDs.

Visually guided temporomandibular joint irrigation in patients with chronic closed lock: clinical outcome and its relationship to intra-articular morphologic changes

OBJECTIVE

The aim of this study was to evaluate the clinical outcome after visually guided irrigation (VGIR) of the temporomandibular joint (TMJ) and its relationship with postoperative arthroscopic changes.

STUDY DESIGN

Of the original 69 patients, thirty patients (30 TMJs) underwent VGIR of the TMJ a second time. After the first VGIR, the clinical outcome was assessed, and 18 patients were assigned to the good outcome group. The remaining 12 patients were assigned to the poor outcome group. The arthroscopic findings related to the articular surface, synovial lining, and fibrous adhesion scores were recorded. Then, the arthroscopic findings in the first and second VGIR were compared.

RESULTS

The intra-articular tissue status between the first and second VGIR was unchanged in approximately 40% of all joints. No significant differences with respect to an improvement in tissue status were found when the good outcome and poor outcome groups were compared.

CONCLUSIONS

In patients with chronic closed lock of the TMJ, a clinical improvement after VGIR does not seem to be accompanied by improved intra-articular tissue status.

Specific expression of inducible nitric oxide synthase in the synovium of the diseased temporomandibular joint

OBJECTIVE

The expression of inducible nitric oxide synthase (iNOS) in temporomandibular joint (TMJ) specimens obtained arthroscopically from diseased TMJs was investigated by using immunohistochemistry and compared with clinical, arthroscopic, and histologic findings.

STUDY DESIGN

Synovial biopsies were obtained arthroscopically from 18 TMJs in 15 patients with symptomatic internal derangement (ID) or osteoarthritis (OA). We also obtained arthroscopic biopsies from 8 control TMJs (3 with habitual luxation of the mandible, one with ID with clicking, and 4 with mandibular condyle fractures). The expression of iNOS was examined by immunohistochemistry and was compared with clinical, arthroscopic, and histologic findings.

RESULTS

Definite or intense iNOS immunoreactivity was observed in both the synovial lining cells and the endothelial cells of TMJs with symptomatic ID or OA. Weaker immunoreactivity was present in synovial fibroblasts. In contrast, in TMJs without synovitis (eg, those with habitual luxation of the mandible) the expression of iNOS was weak or marginal. The expression of iNOS correlated significantly with arthroscopic evidence of synovitis (r = 0.406, P <.05) but not with cartilaginous degeneration (P >.05). The expression of iNOS also correlated with the histologic grade of the synovial lining cell layers (r = 0.530, P <.05). However, in patients with ID or OA of the TMJ, there was no statistically significant correlation between the intensity of iNOS immunoreactivity and clinical, arthroscopic, or histologic findings (P >.05).

CONCLUSION

These data clearly suggest that nitric oxide is locally produced in the synovial lining of the TMJ in ID and OA.

Analysis of temporomandibular joint synovial fluid using Fourier transform/infrared spectroscopy

PURPOSE

In recent years infrared spectroscopy has been increasingly used for the analytical determination of biologic fluids and tissues. With the help of this method it was possible to investigate the various types of arthritis affecting the knee joint, among others. The aim of our study was to show that infrared spectroscopy can also be used as a method to analyze the synovial fluid of the temporomandibular joint to differentiate between inflammatory and noninflammatory disorders.

MATERIALS AND METHODS

Using Fourier transform/infrared spectroscopy analysis, comparable absorption spectra with characteristic signals in the corresponding range of wavelength were shown and used to prove pathologic alterations in the synovial fluid. Samples of 22 patients with arthritis of the temporomandibular joint and 12 patients with noninflammatory internal derangement were investigated and compared with each other.

RESULTS

Our measurements presented a distinct intensity difference between the absorption spectra of patients who had arthritis and those without signs of an inflammatory change but with an internal derangement as control specimens. Due to the small number of undiluted samples it was not possible to follow up with a multivariant analysis, necessary for a differential diagnostic evaluation between the individual types of arthritis.

CONCLUSIONS

A certain differentiation between arthritic and noninflamed temporomandibular joints can be noted with infrared spectroscopy of the synovial fluid. This represents a valuable option for minimally invasive diagnostic proof of inflammation in cases of joint disorders.

Characterization of tissue components in the temporomandibular joint disc and posterior disc attachment region: internal derangement and control autopsy specimens compared by morphometry

PURPOSE

Our aim was to morphologically investigate the occurrence of fibroblasts, chondrocytes, and blood vessels in the tissue of the temporomandibular joint (TMJ) disc, the intermediate zone, and the posterior disc attachment region in control autopsy specimens and to compare the results with those observed in corresponding tissues from patients with TMJ internal derangement.

PATIENTS AND METHODS

First, 20 bilateral TMJ disc specimens from selected autopsy cases were analyzed by conventional morphometry. Thus, the volume density of fibroblasts, chondrocytes, and blood vessels was determined. Second, the obtained results from the right joint of the autopsy disc specimens were compared with 12 TMJ disc specimens obtained at surgery from patients with internal derangement.

RESULTS

The tissue compartments of interest (disc, intermediate zone, and posterior disc attachment region) were identified unequivocally in all specimens. None of the autopsy cases showed any significant difference between the right and left joints or related to gender. The only variable that differed between autopsy and patient specimens was volume density of blood vessels, which was higher in patient specimens.

CONCLUSIONS

We found that the volume density of blood vessels was significantly higher in the posterior disc attachment region in patient specimens than in autopsy controls. Whether this reflects a role for vessels in the pathogenesis of TMJ internal derangement or merely is a reaction to another type of injury remains to be settled. In both the autopsy control and patient specimens, chondrocytes and fibroblasts were characteristic for disc respective posterior disc attachment region. Thus it appears that the occurrence of these cells can be used to distinguish TMJ disc from posterior disc attachment in small biopsy specimens.

Dentition status and temporomandibular joint disorders in patients with rheumatoid arthritis

We compared dentition status and temporomandibular joint (TMJ) disorders in 142 women with rheumatoid arthritis (RA, ages, 40 to 69 years) and 143 women of similar age without RA. The RA group had significantly fewer remaining teeth than the non-RA group. Number of decayed, missing, and filled (DMF) teeth, number of edentulous subjects, and number of subjects with complete and removable partial dentures were significantly higher in the RA group. Among RA subjects, 1.4% had unprovoked TMJ pain, 4.9% had pain on mouth opening, and 14.8% noted difficulty with opening. In the RA group, TMJ tenderness was elicited in 9.2%, clicking in 12.7%, and crepitus in 35.9%, representing a significant excess occurrence of crepitus. The prevalence of TMJ disorders was 67.6% in the RA group and 32.9% in the non-RA group; degenerative joint disorders were particularly frequent. TMJ disorders correlated with Steinbrocker stage and the duration of RA.