Relationship between joint effusion, joint pain, and protein levels in joint lavage fluid of patients with internal derangement and osteoarthritis of the temporomandibular joint

Assessing the Efficacy of Arthrocentesis in Managing Temporomandibular Joint Disorders and Internal Derangements: A Case Series

Internal joint derangements (IJD) of the temporomandibular joint (TMJ) encompass a multifaceted array of conditions that have the potential to induce a gradual decline in joint health, ultimately resulting in persistent pain and disruptions in daily living. The management of these conditions poses significant hurdles to achieving effective pain management and restoration of normal TMJ functionality, presenting ongoing challenges in the medical field. At present, the approach of utilizing arthrocentesis in conjunction with intra-articular injections containing corticosteroids (CSs) and hyaluronic acid (HA) is a commonly employed method aimed at addressing chronic pain, surpassing the outcomes of more conservative treatment modalities. Nevertheless, further advancements in treatment strategies are warranted to enhance outcomes and provide holistic relief for individuals with TMJ-related concerns. The effectiveness of arthrocentesis in combination with intra-articular injections of HA and CSs has been demonstrated with the help of five case reports of elderly patients with IJD. All were chronic patients who were unresponsive to conservative management and presented with chronic pain and reduced mouth opening. Open- and closed-mouth magnetic resonance imaging (MRI) provided the diagnosis of IJD, and the patients were treated with arthrocentesis using a two-needle approach that involved flushing the joint space with Ringer's lactate solution followed by intra-articular injections of 0.5 ml HA and 0.5 ml prednisolone at a concentration of 40 mg/ml into the joint space. All patients showed a significant reduction in pain and improvement in mouth opening at the follow-up visits.

Reconstructed magnetic resonance image-based effusion volume assessment for temporomandibular joint arthralgia

BACKGROUND

Joint effusion is often noticed in magnetic resonance image (MRI) and its diagnostic value for arthralgia of the temporomandibular joint (TMJ) remains obscure.

OBJECTIVE

To develop a method for quantitatively evaluating the joint effusion revealed in MRI and its diagnostic value for arthralgia of the TMJ.

METHODS

Two-hundreds and twenty-eight TMJs, 101 with arthralgia (Group P) and 105 without (Group NP) from 103 patients, and 22 TMJs (Group CON) from 11 asymptomatic volunteers were examined by using MRI. The effusion volume was measured after constructing a three-dimensional structure of the joint effusion revealed in MRI by using the ITK-SNAP software. The diagnostic capabilities of the effusion volume on arthralgia were evaluated with receiver operating characteristic (ROC) curve analysis.

RESULTS

Totally 146 joints showed MRI signs of joint effusion, including nine joints from Group CON. However, the medium volume was greater in Group P (66.65 mm3 ), but was much similar in Group CON (18.33 mm3 ) to Group NP (27.12 mm3 ). The effusion volume larger than 38.20 mm3 was validated to discriminate Group P from Group NP. The AUC value was 0.801 (95% CI 0.728 to 0.874), with a sensitivity of 75% and specificity of 78.9%. The median volume of the joint effusion was larger in those with than without bone marrow oedema, osteoarthritis, Type-III disc configurations, disc displacement and higher signal intensity of the retrodiscal tissue (all, p < .05).

CONCLUSION

The present method for evaluate joint effusion volume well discriminated painful TMJs from non-pain ones.

Diagnostic correlation between clinical protocols and magnetic resonance findings in temporomandibular disorders: A systematic review and meta-analysis

BACKGROUND

Our aim was to assess the diagnostic correlation between clinical protocols and magnetic resonance (MRI) findings in temporomandibular disorders (TMDs), including disc displacement with and without reduction (DDwR; DDwoR) and arthralgia.

METHODS

A systematic review performed in two phases according to the PRISMA checklist. Specific indexing terms were used for search of studies assessing TMDs through clinical diagnostic protocols with the aid of Research Diagnostic Criteria for TMDs or Diagnostic Criteria for TMDs. Quality assessment performed using QUADAS-2. Heterogeneity was assessed using I² . Publication bias was assessed using funnel plots. For meta-analysis, we used random effect model or fixed effect. The main outcomes were sensitivity and specificity of clinical protocols.

RESULTS

Fourteen studies included in the qualitative analysis and 11 studies in the meta-analysis. None of the studies fulfilled all criteria of QUADAS-2. High heterogeneity and high publication bias were found among the studies. Clinical protocols for assessing DDwR compared with MRI showed pooled sensitivity of 66% and specificity of 72%. For DDwoR, sensitivity was 61% and specificity 98%. For arthralgia, sensitivity was 43% and specificity 68% for the presence of effusion.

CONCLUSIONS

This review reveals the need for studies with improved quality. Clinical protocols show poor to moderate validity in diagnosis of DDwR and DDwoR compared with MRI. No correlation was found between a clinical diagnosis of arthralgia and MRI effusion. Clinical diagnostic protocols can be used as screening tools, reserving the use of MRI for a more accurate diagnosis in patients with symptoms or dysfunction.

Assessment of bone marrow fat fractions in the mandibular condyle head using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) method

The prevalence of temporomandibular joint disorder (TMD) is gradually increasing, and magnetic resonance imaging (MRI) is becoming increasingly common as a modality used to diagnose TMD. Edema and osteonecrosis in the bone marrow of the mandibular condyle have been considered to be precursors of osteoarthritis, but these changes are not evaluated accurately and quantitatively on routine MRI. The iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) method, as a cutting-edge MRI technique, can separate fat and water using three asymmetric echo times and the three-point Dixon method. The purpose of this study was to analyze the quantitative fat fraction (FF) in the mandibular condyle head using the IDEAL-IQ method. Seventy-nine people who underwent MRI using IDEAL-IQ were investigated and divided into 1) the control group, without TMD symptoms, and 2) the TMD group, with unilateral temporomandibular joint (TMJ) pain. In both groups, the FF of the condyle head in the TMJ was analyzed by two oral and maxillofacial radiologists. In the TMD group, 29 people underwent cone-beam computed tomography (CBCT) and the presence or absence of bony changes in the condylar head was evaluated. The FF measurements of the condyle head using IDEAL-IQ showed excellent inter-observer and intra-observer agreement. The average FF of the TMD group was significantly lower than that of the control group (p < 0.05). In the TMD group, the average FF values of joints with pain and joints with bony changes were significantly lower than those of joints without pain or bony changes, respectively (p < 0.05). The FF using IDEAL-IQ in the TMJ can be helpful for the quantitative diagnosis of TMD.

Assessment of MRI findings and clinical symptoms in patients with temporomandibular joint disorders

OBJECTIVES

To investigate the correlations among various temporomandibular joint (TMJ) findings on MRI and the relationships between MRI findings and symptoms.

METHODS

425 patients (850 TMJs) with temporomandibular joint disorders (TMDs) who underwent MRI were enrolled. Oblique sagittal proton density-weighted and T₂ weighted images in open- and closed-mouth positions were evaluated. MRI findings included disc configuration, disc position, condylar morphology, bone marrow pattern, and joint effusion. Symptoms included TMJ pain, TMJ noise, and limitation of mouth opening. For statistical analyses, Spearman's rank correlation coefficient and logistic regression analysis were applied.

RESULTS

Folded disc, disc displacement without reduction (DDWOR), and osteophytes had significant negative correlations with other normal MRI findings (p < 0.01). DDWOR and marrow edema were associated with TMJ pain. Conversely, osteophytes [odds ratio (OR): 0.52; 95% CI (0.30-0.90)] and combination-type condylar degeneration [OR: 0.45; 95% CI (0.24-0.83)] were associated with decreased risk of TMJ pain. Condylar flattening was positively associated with TMJ noise [OR: 5.25; 95% CI (1.44-19.07)] and negatively associated with limitation of mouth opening [OR: 0.34; 95% CI (0.11-0.99)]. High-grade joint effusion was significantly associated with TMJ pain and noise.

CONCLUSIONS

DDWOR and high-grade joint effusion (an indicator of inflammation in the articular cavity) were associated with TMD symptoms. This finding suggests that treatment strategy for DDWOR and decreasing inflammation might lessen clinical TMD symptoms. Condylar degeneration was not associated with indicators of inflammation or TMJ symptoms. These results suggest that patients with TMD symptoms should undergo initial MRI to allow rapid selection of appropriate therapies.

The intravoxel incoherent motion MRI of lateral pterygoid muscle: a quantitative analysis in patients with temporomandibular joint disorders

OBJECTIVES

To quantitatively evaluate diffusion and perfusion status of lateral pterygoid muscle (LPM) in patients with temporomandibular joint disorder (TMD) by intravoxel incoherent motion (IVIM) imaging and to correlate with findings on temporomandibular joints (TMJs) by conventional MRI.

METHODS

42 patients with TMD underwent MRI. To assess IVIM parameters, diffusion-weighted imaging was obtained by spin-echo-based single-shot echoplanar imaging. Regions of interest were created on all diffusion-weighted images of the superior belly of the lateral pterygoid (SLP) and inferior belly of the lateral pterygoid (ILP) at b-values 0-500 s mm^-2. Then, IVIM parameters, diffusion (D) and perfusion (f) were calculated using biexponential fittings. The correlation of these values with conventional MRI findings on TMJs was investigated.

RESULTS

For SLP, the f parameter in TMJs with anterior disc displacement without reduction was significantly higher than that in normal ones (p = 0.015). It was also significantly higher in TMJs with joint effusion than in those without (p = 0.016). On the other hand, for both SLP and ILP, the D parameter significantly increased in TMJs with osteoarthritis compared with those without (p = 0.015 and p = 0.022, respectively).

CONCLUSIONS

Pathological changes of LPM in patients with TMD may be quantitatively evaluated by IVIM parameters.

The application of T2W SPIR-FLAIR in the diagnosis of hip synovitis in patients with spondyloarthritis

OBJECTIVE

To investigate the feasibility and accuracy of T₂ weighted spectral pre-saturation inversion recovery combined with fluid-attenuated inversion recovery (T2W SPIR-FLAIR) in the diagnosis of hip synovitis in patients with spondyloarthritis (SpA).

METHODS

10 volunteers underwent a T2W SPIR and 4 T2W SPIR-FLAIR sequence scans with different inversion times (TIs) to determine the optimum TI that could effectively suppress the intra-articular fluid signals. Hip MRI including T2W SPIR-FLAIR and enhanced T₁ weighted (T1W) SPIR sequences was performed in 45 patients with SpA and totally 90 hips were evaluated. McNemar's test and Kappa test were used to compare the diagnostic results of synovitis between T2W SPIR-FLAIR and enhanced T1W SPIR.

RESULTS

A TI of 2100 ms was selected as the optimum TI. 32 hips from 17 patients exhibited high signal intensity within the articular cavity on both T2W SPIR-FLAIR and enhanced T1W SPIR sequences, while only 3 hips showed high signals within the articular cavity on T2W SPIR-FLAIR. The remaining 55 hips did not show high signals within the articular cavity on both sequences. The T2W SPIR-FLAIR and enhanced T1W SPIR sequences had similar values in the diagnosis of hip synovitis (p = 0.25) and a high degree of diagnostic consistency (Kappa = 0.929).

CONCLUSION

T2W SPIR-FLAIR can effectively suppress the intra-articular fluid signals, while retaining the signals of thickened synovial membranes and can be used for the diagnosis of hip synovitis in patients with SpA. Advances in knowledge: The enhanced T1W SPIR is a classic sequence for synovitis diagnosis, but it requires the injection of contrast agents. The T2W SPIR-FLAIR and enhanced T1W SPIR sequences had similar values in the diagnosis of hip synovitis (p = 0.25) and a high degree of diagnostic consistency (Kappa = 0.929).

The usefulness of diagnostic imaging for the assessment of pain symptoms in temporomandibular disorders

The causes of pain symptoms in the temporomandibular joint (TMJ) and masticatory muscle (MM) regions may not be determined by clinical examination alone. In this review, we document that pain symptoms of the TMJ and MM regions in patients with temporomandibular disorders (TMDs) are associated with computed tomography and magnetic resonance (MR) findings of internal derangement, joint effusion, osteoarthritis, and bone marrow edema. However, it is emphasized that these imaging findings must not be regarded as the unique and dominant factors in defining TMJ pain. High signal intensity and prominent enhancement of the posterior disk attachment on fat saturation T2-weighted imaging and dynamic MR imaging with contrast material are closely correlated with the severity of TMJ pain. Magnetic transfer contrast, MR spectroscopy, diffusion tensor imaging, and ultrasonography findings have helped identify intramuscular edema and contracture as one of the causes of MM pain and fatigue. Recently, changes in brain as detected by functional MR neuroimaging have been associated with changes in the TMJ and MM regions. The thalamus, the primary somatosensory cortex, the insula, and the anterior and mid-cinglate cortices are most frequently associated with TMD pain.

Is There an Association Between Temporomandibular Joint Effusion and Arthralgia?

PURPOSE

The literature on joint effusion (JE) and its association with clinical and radiologic variables in patients with temporomandibular disorders (TMDs) is inconsistent and is characterized by multiple methodologic limitations. The primary aim of this investigation was to evaluate the association between magnetic resonance imaging (MRI) identified JE and temporomandibular joint (TMJ) arthralgia. The secondary aim of this investigation was to determine the association between JE and other clinical and MRI-identified soft tissue characteristics.

MATERIALS AND METHODS

A retrospective cohort study was conducted. Clinical and soft tissue imaging assessments were carried out according to the Diagnostic Criteria for Temporomandibular Disorders guidelines. The dependent variable was JE and the primary independent variable was arthralgia. The secondary independent variables were TMJ pain-associated characteristics and MRI-identified variables. When applicable, Pearson χ² or t test was used to determine the statistical associations between JE and clinical characteristics and between JE and MRI-identified variables. Furthermore, generalized estimating equation (GEE) modeling was conducted to determine which of the independent clinical and MRI-identified variables were associated with JE.

RESULTS

Data for 158 participants, representing 312 joints, were extracted. The mean age of the female sample (59.4%) was 31 ± 11.1 years and that of the male sample (40.6%) was 29.8 ± 9.7 years. No association was found between JE and arthralgia. However, statistically significant associations were found between JE and lateral disc rotation (P = .001) and between JE and disc position in the coronal and sagittal planes (P = .001). The GEE model suggested that disc displacement with reduction (odds ratio = 2.5) was a statistically relevant contributing factor for JE in the absence of degenerative joint disease.

CONCLUSION

Results associated JE with the position of the disc in the sagittal plane. No association was found between JE and arthralgia or TMJ pain-associated clinical characteristics in patients with TMDs.

Pain profiling of patients with temporomandibular joint arthralgia and osteoarthritis diagnosed with different imaging techniques

Background

Clinical differentiation between pain mechanisms of temporomandibular joint (TMJ) arthralgia and osteoarthritis (OA) is challenging. The aims were to compare somatosensory function at the TMJs and conditioned pain modulation (CPM) effects between TMJ arthralgia and OA patients diagnosed clinically and based on different imaging techniques and age- and gender-matched healthy controls (n = 41).

Methods

Patients (n = 58) underwent standard clinical examination and three different TMJ imaging modalities. After each examination, they were classified into arthralgia or OA based on the findings. TMJ region somatosensory testing was performed in all participants. Z-scores were calculated for patients based on healthy reference data. CPM was tested by comparing pressure pain thresholds (PPTs) at TMJ and thenar (control) before, during and after the application of painful and nonpainful cold stimuli. Data were analyzed using analyses of variance.

Results

Somatosensory abnormalities were commonly detected in both patient groups. Assessment of somatosensory function at the TMJ revealed that arthralgia patients were less sensitive to warmth, cold and tactile stimuli than OA patients (P < 0.048). OA patients showed pressure hyperalgesia compared with arthralgia patients (P = 0.025). There was a significant CPM effect at both test sites during painful cold application in all groups (P < 0.001). There was no significant difference in the relative CPM effect between groups except for clinically diagnosed arthralgia patients showing reduced CPM effect compared with controls (P = 0.047).

Conclusions

Pain profiles including somatosensory function differed between TMJ arthralgia and OA patients although CPM effects were similar in patients and controls. Thus, different TMJ pain conditions may share common pain mechanisms but the present study for the first time also indicated that differential pain mechanisms could be involved.

Electronic supplementary material

The online version of this article (doi:10.1186/s10194-016-0653-6) contains supplementary material, which is available to authorized users.

Inflammatory biomarkers in osteoarthritis

Osteoarthritis (OA) is highly prevalent and a leading cause of disability worldwide. Despite the global burden of OA, diagnostic tests and treatments for the molecular or early subclinical stages are still not available for clinical use. In recent years, there has been a large shift in the understanding of OA as a "wear and tear" disease to an inflammatory disease. This has been demonstrated through various studies using MRI, ultrasound, histochemistry, and biomarkers. It would of great value to be able to readily identify subclinical and/or sub-acute inflammation, particularly in such a way as to be appropriate for a clinical setting. Here we review several types of biomarkers associated with OA in human studies that point to a role of inflammation in OA.

Correlation between clinical symptoms and magnetic resonance imaging findings in patients with temporomandibular joint internal derangement

Objectives

The purpose of this study was to clarify which findings in magnetic resonance imaging (MRI) are good predicators of pain and mouth opening limitation in patients with temporomandibular joint (TMJ) internal derangement (ID).

Materials and Methods

Clinical examinations for pain and mouth opening limitation were conducted for suspected TMJ ID. MRI scans were taken within a week of clinical examinations. On the oblique-sagittal plane image, readings were obtained in terms of the functional aspect of disc position, degree of displacement, disc deformity, joint effusion, and osteoarthrosis. Multiple logistic regression analyses were conducted to identify the predictors of pain and mouth opening limitation.

Results

A total of 48 patients (96 TMJs) were studied, including 39 female patients and 9 male patients whose ages ranged from 10 to 65 years. The resultant data showed significant correlations between pain and the MR imaging of the degree of disc displacement (P<0.05). The probability of there being pain in moderate to significant cases was 9.69 times higher than in normal cases. No significant correlation was found between mouth opening limitation and MRI findings.

Conclusion

We identified a significant correlation between clinical symptoms and MRI findings of ID. The degree of anterior disc displacement may be useful for predicting pain in patients with TMJ ID.

Structure and Size-selective Permeability of the Synovial Membrane of the Temporomandibular Joint of the Mouse Measured by MR Imaging at 7T

PURPOSE

We analyzed the anatomical structure of the temporomandibular joint (TMJ) and molecular weight dependency of synovial membrane permeability in mice using 7-tesla magnetic resonance (MR) imaging.

METHODS

We obtained 3-dimensional (3D) T1-weighted gradient echo (3D-T1W) and 3D T2-weighted rapid acquisition with relaxation enhancement (3D-T2W RARE) MR images of the TMJ of male C57BL6 mice with voxel resolution of 65 µm. Two-dimensional (2D) T1w images were measured every 45 s before and after bolus intravenous (IV) injection of contrast reagents: gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA; 0.5 kDa); oligomer-based contrast agent (CH3-DTPA-Gd; 2.1 kDa); gadolinium-labeled polylysine (Gd-polylysine; 10 kDa); and gadolinium-labeled albumin (Gd-albumin; 74 kDa).

RESULTS

T1W images depicted the temporal bone and mandibular condyle as regions with lower signal intensity and the disc as a region of intermediate intensity. In the Gd-DTPA-enhanced T1W and T2W images, the articular disc could be identified as a region with lower signal intensity than that of the upper and lower joint cavities. After IV injection of Gd-DTPA or CH3-DTPA-Gd, the signal intensity of the joint cavities increased within 10 min, but this increase was not shown with Gd-polylysine and Gd-albumin.

CONCLUSION

The structural findings obtained by MR imaging agreed with those obtained by hematoxylin-eosin staining under light microscopy. Contrast-enhanced MR imaging suggested that smaller (<2.1 kDa) but not larger (>10 kDa) molecules can permeate the synovial membrane. Our results suggest the utility of MR imaging for analyzing the structure of the TMJ as well as permeability of the synovial membrane.

Relationship between pain and effusion on magnetic resonance imaging in temporomandibular disorder patients

Purpose

This study was performed to find the relationship between pain and joint effusion using magnetic resonance imaging (MRI) in temporomandibular disorder (TMD) patients.

Materials and Methods

The study subjects included 232 TMD patients. The inclusion criteria in this study were the presence of spontaneous pain or provoked pain on one or both temporomandibular joints (TMJs). The provoked pain was divided into three groups: pain on palpation (G1), pain on mouth opening (G2), and pain on mastication (G3). MRI examinations were performed using a 1.5-T MRI scanner. T1- and T2-weighted images with para-sagittal and para-coronal images were obtained. According to the T2-weighted image findings, the cases of effusions were divided into four groups: normal, mild (E1), moderate (E2), and marked effusion (E3). A statistical analysis was carried out using the χ² test with SPSS (version 12.0, SPSS Inc., Chicago, IL, USA).

Results

Spontaneous pain, provoked pain, and both spontaneous and provoked pain were significantly related to joint effusion in TMD patients (p<0.05). However, among the various types of provoked pain, pain on palpation of the masticatory muscles and TMJ (G1) was not related to joint effusion in TMD patients (p>0.05).

Conclusion

Spontaneous pain was related to the MRI findings of joint effusion; however, among the various types of provoked pain, pain on palpation of the masticatory muscles and TMJ was not related to the MRI findings of joint effusion. These results suggest that joint effusion has a significant influence on the prediction of TMJ pain.

Magnetic Resonance Evidence of Joint Effusion of the Temporomandibular Joint After Fractures of the Mandibular Condyle: A Preliminary Report

To investigate the clinical significance of magnetic resonance (MR) evidence of joint effusion of the temporomandibular joint after mandibular condylar fractures, magnetic resonance imaging (MRI) was performed on 18 joints in 15 patients with either unilateral or bilateral mandibular condylar fractures using a 1.5 Tesla MRI scanner (Signa, General Electric, Milwaukee, WI). MR evidence of joint effusion was evaluated and compared with the types and the positions of the fractures. MR evidence of joint effusion was observed in 11 of 18 TMJs, which was 61% of the condylar fractures. It appeared more frequently after fractures with dislocation than those without dislocation (p < 0.05). In addition, MR evidence of effusion appeared more frequently in TMJs after high condylar fractures (head to upper neck) than low condylar fractures (lower neck to subcondylar) (p < 0.05). These findings indicate that MR evidence of joint effusion may serve as a marker for the detection of severe intra-articular damage to the TMJ after mandibular condyle fractures.

Relationship between anterior disc displacement with/without reduction and effusion in temporomandibular disorder patients using magnetic resonance imaging

PURPOSE

This study was performed to evaluate the relationship between anterior disc displacement and effusion in temporomandibular disorder (TMD) patients using magnetic resonance imaging (MRI).

MATERIALS AND METHODS

The study subjects included 253 TMD patients. MRI examinations were performed using a 1.5 T MRI scanner. T1- and T2-weighted images with para-sagittal and para-coronal images were obtained. According to the MRI findings, temporomandibular joint (TMJ) disc positions were divided into 3 subgroups: normal, anterior disc displacement with reduction (DWR), and anterior disc displacement without reduction (DWOR). The cases of effusion were divided into 4 groups: normal, mild (E1), moderate (E2), and marked effusion (E3). Statistical analysis was made by the Fisher's exact test using SPSS (version 12.0, SPSS Inc., Chicago, IL, USA).

RESULTS

The subjects consisted of 62 males and 191 females with a mean age of 28.5 years. Of the 253 patients, T1- and T2-weighted images revealed 34 (13.4%) normal, DWR in 103 (40.7%), and DWOR in 116 (45.9%) on the right side and 37 (14.6%) normal, DWR in 94 (37.2%), and DWOR in 122 (48.2%) joints on the left side. Also, T2-images revealed 82 (32.4%) normal, 78 (30.8%) E1, 51 (20.2%) E2, and 42 (16.6%) E3 joints on the right side and 79 (31.2%) normal, 85 (33.6%) E1, 57 (22.5%) E2, and 32 (12.7%) E3 on the left side. There was no difference between the right and left side.

CONCLUSION

Anterior disc displacement was not related to the MRI findings of effusion in TMD patients (P>0.05).

Increased levels of interleukin-6 in synovial lavage fluid from patients with mandibular condyle fractures: correlation with magnetic resonance evidence of joint effusion

PURPOSE

The aim of the present study was to investigate the relation between magnetic resonance (MR) evidence of joint effusion and concentrations of proinflammatory cytokines, including interleukin (IL)-1β and IL-6, in washed-out synovial fluid samples obtained from patients with mandibular condyle fractures.

PATIENTS AND METHODS

Twenty-five joints in 23 patients with mandibular condyle fractures were examined. Computed tomography was used to determine the position of the fracture and MR examination was performed in all cases. Twenty-five joints underwent temporomandibular joint (TMJ) irrigation before surgical treatment for the fractures. The detection rates and concentrations of the tested cytokines were determined, and their relations to evidence of joint effusion and positions of the condylar fractures were analyzed.

RESULTS

Six TMJ fractures were found in the head, 10 in the upper neck, 4 in the lower neck, and 5 in the subcondyle. MR evidence of joint effusion was observed in 17 of 25 TMJs (68.0%). The detection rate and concentration of IL-6 were significantly higher in patients with MR evidence of joint effusion and those with high condylar fractures. Moreover, there was a correlation between joint effusion grade and IL-6 concentration.

CONCLUSIONS

The present findings showed a correlation between MR evidence of joint effusion and concentration of IL-6 in washed-out synovial fluid samples collected from patients with mandibular condyle fractures. These results may provide support for arthrocentesis as a reasonable treatment modality for high condylar fractures.

Progression of cartilage degradation, bone resorption and pain in rat temporomandibular joint osteoarthritis induced by injection of iodoacetate

Background

Osteoarthritis (OA) is an important subtype of temporomandibular disorders. A simple and reproducible animal model that mimics the histopathologic changes, both in the cartilage and subchondral bone, and clinical symptoms of temporomandibular joint osteoarthritis (TMJOA) would help in our understanding of its process and underlying mechanism.

Objective

To explore whether injection of monosodium iodoacetate (MIA) into the upper compartment of rat TMJ could induce OA-like lesions.

Methods

Female rats were injected with varied doses of MIA into the upper compartment and observed for up to 12 weeks. Histologic, radiographic, behavioral, and molecular changes in the TMJ were evaluated by light and electron microscopy, MicroCT scanning, head withdrawal threshold test, real-time PCR, immunohistochemistry, and TUNEL assay.

Results

The intermediate zone of the disc loosened by 1 day post-MIA injection and thinned thereafter. Injection of an MIA dose of 0.5 mg or higher induced typical OA-like lesions in the TMJ within 4 weeks. Condylar destruction presented in a time-dependent manner, including chondrocyte apoptosis in the early stages, subsequent cartilage matrix disorganization and subchondral bone erosion, fibrosis, subchondral bone sclerosis, and osteophyte formation in the late stages. Nociceptive responses increased in the early stages, corresponding to severe synovitis. Furthermore, chondrocyte apoptosis and an imbalance between anabolism and catabolism of cartilage and subchondral bone might account for the condylar destruction.

Conclusions

Multi-level data demonstrated a reliable and convenient rat model of TMJOA could be induced by MIA injection into the upper compartment. The model might facilitate TMJOA related researches.

Increased levels of soluble cytokine receptors in the synovial fluid of temporomandibular joint disorders in relation to joint effusion on magnetic resonance images

PURPOSE

The purpose of this study is to clarify the significance of joint effusion (JE) on T2-weighted magnetic resonance images of the temporomandibular joint (TMJ) in comparison to various soluble cytokine receptors in the synovial fluid of patients with temporomandibular disorders (TMDs).

PATIENTS AND METHODS

Magnetic resonance imaging of 55 TMJs of 55 patients with TMD was performed, and synovial fluid samples were obtained on the same day. The grade of JE was evaluated on a scale from 0 to 3, with grade 0 indicating the absence of JE and grades 1 to 3 indicating the presence of JE. Correlations were measured between JE and the concentrations of soluble tumor necrosis factor receptors I and II, interleukin (IL) 6 soluble receptor, IL-1 soluble receptor type II, and IL-1 receptor antagonist and protein in the synovial fluid samples.

RESULTS

The mean concentrations of cytokine receptors in the synovial fluid were significantly higher in the 30 joints with JE than in the 25 joints without JE. There were no correlations between the JE grade and the level of any mediators.

CONCLUSION

Increased levels of cytokine receptors are likely to influence the expression of JE and may play important roles in the pathogenesis of TMD. These results also suggest that JE may reflect synovial inflammation of the TMJ.

Temporomandibular joint pain and synovial fluid analysis: a review of the literature

The pathophysiology of temporomandibular joint pain is not well understood. A significant amount of research has been conducted to evaluate synovial fluid in these patients and in healthy controls. Qualitative and quantitative analyses of the synovial fluid have shown a significant difference between these groups. A multitude of inflammatory mediators and degradation products have been identified. The concentration of these products has been shown to correlate with several clinical parameters including pain, chronicity, severity of degenerative change, and response to treatment. A common inflammatory pathway would appear to be involved in most patients. At the present time, synovial fluid analysis does not have the sensitivity or specificity to allow specific diagnoses and targeted treatment. Continued research with the specific aim of establishing more appropriate therapeutic modalities based on the biochemical pathways is warranted.

Research diagnostic criteria for temporomandibular disorders (RDC/TMD): development of image analysis criteria and examiner reliability for image analysis

OBJECTIVE

As part of the Multisite Research Diagnostic Criteria For Temporomandibular Disorders (RDC/TMD) Validation Project, comprehensive temporomandibular joint diagnostic criteria were developed for image analysis using panoramic radiography, magnetic resonance imaging (MRI), and computerized tomography (CT).

STUDY DESIGN

Interexaminer reliability was estimated using the kappa (kappa) statistic, and agreement between rater pairs was characterized by overall, positive, and negative percent agreement. Computerized tomography was the reference standard for assessing validity of other imaging modalities for detecting osteoarthritis (OA).

RESULTS

For the radiologic diagnosis of OA, reliability of the 3 examiners was poor for panoramic radiography (kappa = 0.16), fair for MRI (kappa = 0.46), and close to the threshold for excellent for CT (kappa = 0.71). Using MRI, reliability was excellent for diagnosing disc displacements (DD) with reduction (kappa = 0.78) and for DD without reduction (kappa = 0.94) and good for effusion (kappa = 0.64). Overall percent agreement for pairwise ratings was >or=82% for all conditions. Positive percent agreement for diagnosing OA was 19% for panoramic radiography, 59% for MRI, and 84% for CT. Using MRI, positive percent agreement for diagnoses of any DD was 95% and of effusion was 81%. Negative percent agreement was >or=88% for all conditions. Compared with CT, panoramic radiography and MRI had poor and marginal sensitivity, respectively, but excellent specificity in detecting OA.

CONCLUSION

Comprehensive image analysis criteria for the RDC/TMD Validation Project were developed, which can reliably be used for assessing OA using CT and for disc position and effusion using MRI.

Magnetic resonance signal intensity from retrodiscal tissue related to joint effusion status and disc displacement in elderly patients with temporomandibular joint disorders

Magnetic resonance imaging (MRI) on patients with temporomandibular joint disorders (TMD) has revealed that a decrease and/or increase in signal intensity from retrodiscal tissue, joint effusion (the excessive accumulation of joint fluid) and articular disc displacement are related to TMD. However, the effect of aging on these phenomena has yet to be clarified. This study was carried out to explore the relationship between changes in signal intensity from retrodiscal tissue, joint fluid status and pathological disc conditions in elderly patients with TMD. Twenty patients aged over 60 years were examined. They consisted of one man and 19 women, and ranged between 60 and 79 years in age (mean, 66.0 years). The relationships between decreased signal intensity on proton-density-weighted (PDW) images and increased signal intensity on T2-weighted (T2W) MR images from retrodiscal tissue, joint fluid status and state of articular disc were examined. Joint fluid status was classified into 5 levels by extent of high signal areas in upper and lower articular spaces on T2W images. Disc displacement status was evaluated by PDW images. The Wilcoxon test was applied for the statistical analysis. The group showing increased T2W signal intensities from the retrodiscal tissue consisted of 31 out of 40 joints (77.5%). This group showed a significant difference in comparison with the other groups in which no apparent joint fluid was shown (p<0.05). There were no statistically significant differences among other categories. The results suggest a negative relationship between joint fluid and increased signal intensity from retrodiscal tissue due to reflection of the inflammatory reaction in TM joints.

Interexaminer reliability of T2-weighted magnetic resonance imaging for lumbar bright facet sign

OBJECTIVE

The aims of this study were to characterize the bright facet response within the lumbar spine, to identify a constellation of findings associated with the response, and to quantify the interexaminer agreement on the previous objectives.

METHODS

A retrospective study of lumbar magnetic resonance images obtained on 105 (N = 105) adult subjects (62 men and 43 women; age range, 18-84 years; mean age, 46.51 +/- 16.01 years) were reviewed by 2 musculoskeletal radiologists for the presence of high signal within the facet articulations (bright facet response) on fast spin echo T2-weighted images.

RESULTS

Of the 630 lumbar facet articulations imaged (L3/L4 through L5/S1), 340 (54%) and 346 (55%) respectively, per examiner, did show a bright facet response. Interexaminer agreement with respect to the level and grading of a bright facet response was almost perfect with kappa ranging from 0.85 to 0.91 (SE, 0.06). Prevalence of bright facet responses averaged 40.5% at L5/S1, 56.5% at L3/L4, and 66.5% at the L4/L5 level. There was an association with degenerative facet and disk changes.

CONCLUSION

The bright facet response was a common phenomenon on T2-weighted magnetic resonance imaging of the lumbar spine in these cases. There was sufficient agreement with respect to the presence and extent of the bright facet response to conclude that the examiners' determinations were not made by random chance. There exist sufficient repeatability and reliability that a single descriptive term can be applied to unify the bright facet response, the bright facet sign.

Anchored disc phenomenon with a normally positioned disc in the temporomandibular joint: Characteristics and behaviour

We aimed to elucidate the pathogenesis and evaluate the therapeutic behaviour of patients with an anchored disc phenomenon but a normally positioned disc of the temporomandibular joint (TMJ). Fourteen patients with internal derangement including closed lock of one TMJ were examined. All had normally positioned discs. Synovial fluid was collected from the TMJ by arthrocentesis. Their symptoms, and the protein concentration in the synovial fluid, were evaluated. Their median duration of illness was 3 months (range 0.5-12), and the median protein concentration was low (343 microg/ml; range 36-791). Arthrocentesis was successful in nine. Arthroscopic findings in the five unsuccessful cases showed severe intra-articular adhesions of the TMJ. The main intra-articular pathological feature was the presence of adhesions, which might be affected by low protein concentrations in the synovial fluid. These findings may provide a new treatment in patients with normally positioned discs, despite the small number studied.

Temporomandibular Joint Internal Derangement and Osteoarthrosis: Are Effusion and Bone Marrow Edema Prognostic Indicators for Arthrocentesis and Hydraulic Distention?

PURPOSE

Arthrocentesis and hydraulic distention of the temporomandibular joint (TMJ) has proven to be an effective modality in treating patients exhibiting clinical findings consistent with the diagnosis of disc displacement without reduction. The purpose of this study was to investigate whether the magnetic resonance imaging (MRI) variables of effusion and/or bone marrow edema may predict treatment outcomes of arthrocentesis and hydraulic distention of the TMJ.

PATIENTS AND METHODS

The study group comprised 37 consecutive patients with TMJ pain, who were assigned a unilateral clinical TMJ disorder of TMJ pain associated with an internal derangement (ID) type III (disc displacement without reduction) and a TMJ pain side-related MRI diagnosis of disc displacement without reduction associated with osteoarthrosis (OA). Bilateral sagittal and coronal MRI images were obtained immediately before the operation to establish the presence or absence of ID, OA, TMJ effusion, and bone marrow edema. Pain level and mandibular range of motion (ROM) were assessed preoperatively and compared with the respective 2-month follow-up findings. Outcome criteria for success were a ROM >or=35 mm and pain reduction >50%. A logistic regression analysis was used to compute the odds ratio for TMJ effusion and bone marrow edema for successful outcomes (n = 21) versus unsuccessful (n = 16) outcomes.

RESULTS

At the 2-month follow-up, clinical evaluation showed a significant reduction in TMJ pain during function (P = .000), a significant reduction in clinical diagnoses of TMJ disorders (P = .016), and a significant increase in ROM (P = .000). A significant increase in the risk of an unsuccessful outcome of ROM <35 mm and/or pain reduction >or=50% occurred with MRI findings of effusion (odds ratio 1:10.8 = 0.09; P = .007).

CONCLUSIONS

TMJ effusion may prove to be an important prognostic determinant of successful arthrocentesis. However, the data re-emphasize the concept that the prediction of a specific outcome is not a matter of simple linearity, in which the presence of 1 factor may equate with predictive ability, but rather is a function of a complex interaction among different biological variables.

Evaluation of the position, mobility, and morphology of the disc by MRI before and after four different treatments for temporomandibular joint disorders

OBJECTIVES

The purpose of this study was to evaluate changes in disc position, mobility, and morphology in patients with temporomandibular joint disorders (TMD) in response to four different treatments, splint therapy, pumping manipulation, arthrocentesis, and arthroscopic surgery, using magnetic resonance imaging (MRI).

METHODS

Eighty-five joints (85 patients) with unilateral internal derangement or osteoarthritis that were successfully treated were included in this study. The patients were divided into four groups as follows: splint therapy group, pumping manipulation group, arthrocentesis group, and arthroscopic surgery group. Changes in the disc position, mobility, and morphology before and after treatment were compared among the four groups using MRI.

RESULTS

All discs showed anterior disc displacement (ADD) without reduction before treatment. Only 10% of the joints became ADD with reduction after treatment, and the other joints remained ADD without reduction in spite of treatment. Discs treated by arthroscopic surgery were located more anteriorly compared with pre-treatment. In pre-treatment MRI, the rate of stuck disc increased as the stage of the treatment advanced. In post-treatment MRI, all temporomandibular joints (TMJs) had mobile discs. The disc deformity advanced after arthrocentesis and arthroscopic surgery.

CONCLUSIONS

Even though clinical signs and symptoms were alleviated by treatment, most discs remained ADD without reduction on MRI in spite of treatment. This suggests that the four treatments do not necessarily improve the position and deformity of the disc, and that arthroscopic surgery advances the deformity and anterior displacement of the disc. Disc mobility is important for improving clinical signs and symptoms.

Expression of capsaicin receptor TRPV-1 in synovial tissues of patients with symptomatic internal derangement of the temporomandibular joint and joint pain

OBJECTIVE

To elucidate expression of capsaicin receptor TRPV-1 in synovial tissues of the human temporomandibular joint (TMJ) with internal derangement and discuss its relationship with joint pain.

STUDY DESIGN

Fifty-four TMJs in 54 patients were examined using an immunohistochemical technique. As controls, 10 TMJs with habitual dislocation without pain were also examined.

RESULTS

TRPV-1 was expressed mainly in the blood vessels beneath the lining cells in synovial tissues from 31 of the 54 joints with internal derangement and from 8 of the 10 control joints. The extent score of TRPV-1-stained cells with internal derangement was not significantly higher than that of controls. The extent score of TRPV-1 showed no correlation with joint pain.

CONCLUSIONS

TRPV-1 was detected in the region of the posterior disk attachment of synovial tissues from the TMJ in patients with internal derangement and controls. TRPV-1 may play a role in maintenance of the physiologic condition of the TMJ.

Electrophoretic separation of the synovial fluid proteins in patients with temporomandibular joint disorders

OBJECTIVE

The present study was performed to characterize the patterns of protein expression in the synovial fluid (SF) of patients with temporomandibular joint disorders (TMD) by electrophoretic fractionation.

STUDY DESIGN

Samples of the SF of 26 consecutive patients consisting of 16 with closed locking (CL group) and 10 with osteoarthritis (OA group), as well as 7 asymptomatic control subjects (AS group), were analyzed in the present study. SF samples were obtained from the upper compartment of the temporomandibular joint (TMJ) and equal quantities of SF protein were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).

RESULTS

The mean total protein concentrations in the SF from both of the TMD groups were higher than that in the AS group (1353 microg/mL in the CL group and 2485 microg/mL in the OA group vs 615 microg/mL in the AS group; P < .01). Moreover, the mean total SF protein concentration was higher in the OA group than in the CL group (P < .01). There was a correlation between the total protein concentration in the SF from both patient groups and the degree of expanded joint effusion (P = .003, r = 0.685). Approximately 22 different protein bands with molecular weights ranging from 14 to 700 kd were clearly discernible on electrophoresis. The relative amounts of specific proteins in the SF of the TMD group were also different from those in the AS group (P < .05). The major difference in total protein concentration appeared to be due to the increased abundance of relatively high molecular weight proteins (>140 kd) in the TMD patients as compared to the AS group.

CONCLUSIONS

The SF of patients with TMD showed significant quantitative differences in total protein abundance as compared to healthy subjects. Moreover, this protein abundance was correlated strongly with the degree of expanded joint effusion. The major difference in total protein concentration appeared to be due to the increased abundance of relatively high molecular weight polypeptides in the TMD patients as compared to the healthy control subjects. These observations of changes in the pattern of protein expression may help in understanding the etiological factors involved in the pathophysiology of TMD.

Electrophoretically separation of the synovial fluid proteins in rabbit temporomandibular arthritis induced by mechanical loading

BACKGROUND

The concentration of protein in synovial fluid (SF) of temporomandibular joints (TMJs) with disorders tends to be increased. We investigated the protein composition of SF of rabbits in which arthritis of the TMJ was induced.

METHOD

Arthritis was induced in six TMJs in six rabbits by exertion of a load for 4 weeks. Six non-loaded TMJs in six rabbits served as controls. The protein concentration and content in TMJ SF of the two groups were compared.

RESULTS

The mean protein concentration was higher in the SF of the loaded group than in that of the non-loaded group (1824 microg/ml vs. 398 microg/ml, P = 0.002). Proteins with molecular weights of more than 95 kDa were abundant in the loaded group (P < 0.05).

CONCLUSION

Temporomandibular arthritis induced by mechanical loading in rabbit is accompanied by an increase in the abundance of relatively high molecular weight proteins in SF.

The relationship of bone marrow edema pattern in the mandibular condyle with joint pain in patients with temporomandibular joint disorders: longitudinal study with MR imaging

The purpose of this study was to investigate the course of bone marrow edema pattern (decreased signal intensity on T1- or proton-density-weighted images and increased signal intensity on T2-weighted fat-suppressed images) in the mandibular condyle after improvement in clinical symptoms, and to clarify its relationship with temporomandibular joint (TMJ) pain. This study was based on 14 joints of 11 patients (all female, mean age 37.5 years) with TMJ disorders showing condylar bone marrow edema pattern on initial magnetic resonance (MR) images. All joints were re-evaluated clinically and using MR images after relief of joint pain following arthrocentesis combined with non-surgical treatment. The time interval between the initial and follow-up MR images ranged from 14 to 27 months (mean 17 months). Of the 14 joints, 4 joints (28.6%) showed a normal bone marrow signal, whereas 10 joints (71.4%) showed persistent bone marrow edema pattern on follow-up MR images (P = 0.125). Therefore, the reduction in TMJ pain did not correlate with resolution of bone marrow edema pattern in most joints. The results of this study suggest that the bone marrow edema pattern in the mandibular condyle does not always contribute to the occurrence of joint pain in patients with TMJ disorders.

Temporomandibular joint internal derangement: relationship between joint pain and MR grading of effusion and total protein concentration in the joint fluid

OBJECTIVES

The objective of this study was to determine whether there is any association between the protein concentration in the synovial fluid and (i) the amount of articular hydrops, as graded in magnetic resonance (MR) images, and (ii) joint pain in temporomandibular joints (TMJs) with and without displacement of the disc.

PATIENTS AND METHODS

This study involved 16 joints in 16 patients referred to our clinic with the complaint of pain and limited mouth opening. The control group consisted of 15 joints in 15 patients with unilaterally normal disc and condyle relationship and no pain while the opposite side had a non-painful joint with disc displacement without reduction (DDwoR). The subjects and controls were different individuals and only a single joint was used for each. Pain and dysfunction were evaluated by visual analogue scale. Bilateral proton density and T2 weighted images of the TMJs of the 31 subjects were analysed for fluid and condyle bony changes as well as disc position. The amount of fluid, identified as an area of high signal intensity in the region of the upper and lower joint spaces, was characterized as none, minimal, moderate or marked. Arthrocentesis was performed both for synovial fluid analysis of total protein concentration and the treatment of the joints with DDwoR. Total protein concentration was measured by using protein dye binding on spectrophotometry.

RESULTS

All patients experienced a significant (P<0.01) increase in maximal mouth opening immediately post-arthrocentesis. In the study group, the disc was displaced most frequently in an anteriormedial direction (75%) and deformation of disc form was seen in 13 joints. Condylar bony changes were seen in 27% of joints in the control group and in 81% of joints in the study group. A statistically significant association was found between joints with disc displacement, disc form and condylar bony changes (P<0.05). In the control group, only one joint, which had an osteophyte, showed joint effusion (JE) with moderate fluid. In the study group, only four joints had no fluid (25%). JE was found in 10 (63%) joints with disc displacement on anteromedial direction, in 10 (63%) joints with disc deformation and in 10 (63%) joints with osteophytes and erosion. Mean total protein concentration was 16.87+/-7.9 (range 7.4-34.1 mg dl-1) in control joints, 55.08+/-35.16 (range 21.5-153.9 mg dl-1) in study joints. There were significant differences in the mean total protein concentration between the control and study groups (P<0.01). Significant positive correlation was found between the total protein concentration and JE (r=0.65, P<0.01). No significant correlation was found between the level of pain and dysfunction and JE and total protein concentration in either control or study groups (P>0.05).

CONCLUSION

Pain in the TMJ was not related to MR findings of effusion in internal derangement and synovial fluid aspirate findings of total protein concentration. However, total protein concentration was related to the amount of JE in DDwoR joints and painful joints were more likely to demonstrate the JE.

Levels of soluble cytokine factors in temporomandibular joint effusions seen on magnetic resonance images

OBJECTIVE

To elucidate the correlations between joint effusion (JE) on T2-weighted magnetic resonance images (MRI) of the temporomandibular joint (TMJ) and the levels of various cytokine receptors, cytokine antagonists, and protein in the synovial fluid of patients with temporomandibular joint disorders (TMD).

STUDY DESIGN

Fifty-five TMJs of 55 patients with TMD were scanned by MRI, and synovial fluid samples were obtained on the same day. The grade of JE was evaluated on a scale of 0 to 3: Grades 0 and 1 indicated absence, and grades 2 and 3 indicated the presence of JE. Correlations were evaluated between JE and the concentrations of soluble tumor necrosis factor receptors I and II (sTNFR-I and sTNFR-II, respectively), IL-6 soluble receptor (IL-6sR), IL-1 soluble receptor type II, and IL-1 receptor antagonist and protein in the synovial fluid of patients with TMD.

RESULTS

The concentrations of sTNFR-I and protein in the group with JE (18 joints) were significantly higher than in the group without JE (37 joints). In addition, there were significant positive correlations between the grade of JE and the levels of sTNFR-I, sTNFR-II, and protein.

CONCLUSIONS

sTNFRs and protein may play important roles in the pathogenesis of TMD. These mediators seem to influence the expression of JE, which may reflect synovial inflammation of the TMJ.

Analysis of tumor necrosis factor-α, interleukin-6, interleukin-1β, soluble tumor necrosis factor receptors I and II, interleukin-6 soluble receptor, interleukin-1 soluble receptor type II, interleukin-1 receptor antagonist, and protein in the synovial fluid of patients with temporomandibular joint disorders

OBJECTIVE

To measure the levels of various cytokines, cytokine receptors, and cytokine antagonists in the synovial fluid of patients with temporomandibular disorders (TMD) and to determine the correlations among these expression levels.

STUDY DESIGN

Synovial fluid was obtained from 55 patients with TMD and from 5 asymptomatic healthy volunteers as controls. The concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-1beta, soluble tumor necrosis factor receptors I and II (sTNFR-I and sTNFR-II), IL-6 soluble receptor (IL-6sR), IL-1 soluble receptor type II, and IL-1 receptor antagonist were determined by enzyme-linked immunosorbent assay.

RESULTS

The concentrations of TNF-alpha, IL-6, IL-1beta, sTNFR-I, and sTNFR-II were significantly higher in the synovial fluid of patients than in controls (P < .05). TNF-alpha level was positively correlated with those of IL-6, sTNFR-I, and sTNFR-II. In particular, there was a highly significant positive correlation between sTNFR-I and sTNFR-II.

CONCLUSION

TNF and sTNFRs in the synovial fluid of patients with TMD may be important in the pathogenesis of these disorders.

Vascular endothelial growth factor concentrations in synovial fluids of patients with symptomatic internal derangement of the temporomandibular joint

BACKGROUND

Vascular endothelial growth factor (VEGF) is an inducer of angiogenesis and permeability of small blood vessels. We determined the concentrations of VEGF in synovial fluid of patients with symptomatic internal derangement of the temporomandibular joint (TMJ).

METHODS

Diluted synovial fluid was collected by a pumping procedure from 22 TMJs of patients with internal derangement and 10 control TMJs. VEGF concentration was determined by an enzyme-linked immunosorbent assay.

RESULTS

The VEGF was detected in 14 of the 22 joints (64%) of patients with internal derangement, at a mean concentration of 67 pg/ml, but in only one control joint (12.5 pg/ml) (P = 0.004 for the difference in concentration). There was a significant correlation between VEGF concentration and total protein concentration in the synovial fluid (P = 0.002).

CONCLUSIONS

The increased concentration of VEGF in patients with symptomatic internal derangement suggests that this growth factor may be involved in the pathogenesis of this condition.

MRI characteristics of anterior disc displacement with and without reduction

OBJECTIVES

The aim of this study was to investigate the differences between magnetic resonance imaging (MRI) characteristics of anterior disc displacement with reduction (ADDR) and without reduction (ADDWR).

METHODS

A clinician and a radiologist, blinded to the results of the clinical examination, independently evaluated the MRI scans of 100 subjects with symptoms of temporomandibular joint (TMJ) disorders. The final sample included 88 subjects in whom there was consensus of disc displacement both between observers and between MRI and clinical examination. There were 130 joints with ADDR and 45 joints with ADDWR in the study. The MRI characteristics such as position, signal intensity and morphology of the disc, degenerative changes, effusion, scar tissue, osteonecrosis and condylar hypermobility were evaluated in the cases of ADDR and ADDWR. The chi(2) test was used to determine the differences between ADDR and ADDWR for these MRI characteristics.

RESULTS

There were no significant differences between ADDR and ADDWR for effusion and degenerative changes. There were significant differences between ADDR and ADDWR for sideways displacement, disc deformation, signal intensity changes, scar tissue, osteonecrosis and condylar hypermobility.

CONCLUSIONS

Degenerative changes and effusion did not appear to be markers of either ADDR or ADDWR. However, the severity of these abnormalities may be correlated with the type of internal derangement. The prevalence of sideways displacement, disc deformation, signal intensity changes, scar tissue, and osteonecrosis was greater in ADDWR than ADDR. These conditions may be considered to be indicators of more advanced and complicated stages of internal derangement. Because the percentage of subluxation was greater in ADDR, localized joint laxity and internal derangement may be correlated.

Relationship of calcitonin gene-related peptide in synovial tissues and temporomandibular joint pain in humans

OBJECTIVE

To elucidate the expression of calcitonin gene-related peptide (CGRP) in synovial tissue taken from the human temporomandibular joint (TMJ) with internal derangement, and discuss the relationship between CGRP and joint pain.

STUDY DESIGN

Using an immunohistochemical technique, 48 joints in 48 patients were examined. As controls, synovial tissue specimens from 7 joints with habitual dislocation without pain were also examined.

RESULTS

In all of the internal derangement and control subjects, CGRP-positive cells were observed in the connective tissues around the blood vessels beneath the lining cells. The extent score of CGRP was significantly higher in the internal derangement group than in the control group (P=.033). There was a significant positive correlation between the extent score of CGRP and joint pain (P=.036, r=0.30).

CONCLUSIONS

These results suggest that the expression of CGRP is increased in the synovial tissues from patients with internal derangement, and that CGRP seems to play an important role in the mechanism of pain production in patients with symptomatic internal derangement.