Correlation of Arthroscopic and Histologic Findings in Synovial Membrane Disease of the Temporomandibular Joint

Synovial microenvironment in temporomandibular joint osteoarthritis: crosstalk with chondrocytes and potential therapeutic targets

Temporomandibular joint osteoarthritis (TMJOA) is considered to be a low-grade inflammatory disease involving multiple joint tissues. The crosstalk between synovium and cartilage plays an important role in TMJOA. Synovial cells are a group of heterogeneous cells and synovial microenvironment is mainly composed of synovial fibroblasts (SF) and synovial macrophages. In TMJOA, SF and synovial macrophages release a large number of inflammatory cytokines and extracellular vesicles and promote cartilage destruction. Cartilage wear particles stimulate SF proliferation and macrophages activation and exacerbate synovitis. In TMJOA, chondrocytes and synovial cells exhibit increased glycolytic activity and lactate secretion, leading to impaired chondrocyte matrix synthesis. Additionally, the synovium contains mesenchymal stem cells, which are the seed cells for cartilage repair in TMJOA. Co-culture of chondrocytes and synovial mesenchymal stem cells enhances the chondrogenic differentiation of stem cells. This review discusses the pathological changes of synovium in TMJOA, the means of crosstalk between synovium and cartilage, and their influence on each other. Based on the crosstalk between synovium and cartilage in TMJOA, we illustrate the treatment strategies for improving synovial microenvironment, including reducing cell adhesion, utilizing extracellular vesicles to deliver biomolecules, regulating cellular metabolism and targeting inflammatory cytokines.

Arthroscopic Assessment of Temporomandibular Joint Pathologies-Is It Possible for Non-Specialists in Arthroscopy? Analysis of Variability and Reliability of Dental Students' Ratings after a Comprehensive One-Semester Introduction

Background: Arthroscopy of the temporomandibular joint (TMJ) plays a long-established role in the diagnostics and therapy of patients suffering from arthrogenic temporomandibular disorders (TMDs), which do not respond adequately to conservative/non-invasive therapy. However, the interpretation of arthroscopic findings remains challenging. This study investigates the reliability and variability of assessing arthroscopic views of pathologies in patients with TMDs by non-specialists in arthroscopy and whether a standardized assessment tool may improve correctness. Methods: Following a comprehensive one-semester lecture, dental students in the clinical stage of education were asked to rate 25 arthroscopic views (freeze images and corresponding video clips) regarding the severity of synovitis, adhesions, and degenerative changes on a scale of 0-10 (T1). The results were compared to ratings stated by two European-board-qualified academic OMF surgeons. In a second round (T2), the students were asked to repeat the ratings using a 10-point rating scheme. Results: With regard to all three subcategories, congruency with the surgeons' results at T1 was at a low level (p < 0.05 in 19/75 cases) and even decreased at T2 after the implementation of the TMDs-SevS (p < 0.05 in 38/75 cases). For both T1 and T2, therefore, the inter-rater agreement was at a low level, showing only a slight agreement for all three subcategories (Fleiss' Kappa (κ) between 0.014 and 0.099). Conclusions: The judgement of the arthroscopic pathologies of the TMJ remains an area of temporomandibular surgery that requires wide experience and training in TMDs to achieve expertise in TMJ arthroscopic assessments, which cannot be transferred by theoretical instruction alone.

Reconstruction of the TMJ and condyle in inflammatory arthritis

Inflammatory arthritis presents a unique destructive process to the temporomandibular joint. This article provides information on the proper diagnosis, treatment planning, and surgical management aimed to provide patients with improvement in pain, function, stability and facial aesthetics. Additionally, it aims to provide a detailed insight on the joint reconstruction options including alloplastic joint replacement, autogenous joint replacement, orthognathic surgery and distraction osteogenesis.

Temporomandibular joint arthroscopy in advanced stages of internal derangement: a retrospective cohort study on the influence of age

The aim of this investigation was to evaluate the outcomes of patients with advanced internal derangement of the temporomandibular joint who underwent operative arthroscopy, according to age stratified into two groups: <45 years and ≥45 years. The study included a series of 194 patients. Outcome variables were pain intensity and mandibular mobility. Additionally, the difference in arthroscopic findings in these age groups was studied. The data analysis included the paired t-test, χ² test, and two-way analysis of variance, with a P-value <0.05 indicating statistical significance. A significant reduction in pain and an improvement in maximum inter-incisal opening (MIO) was observed in both groups starting at 1 month of follow-up (P < 0.01). However, the results for MIO were worse in the ≥45 years group (P=0.036) at 12- and 18-months follow-up. Regarding arthroscopic findings, the study showed a higher prevalence of severe chondromalacia in the ≥45 years group (P = 0.031) and disc displacement without reduction in the <45 years group (P = 0.020). Analysis of variance showed a greater pain reduction if no obliteration of the articular space was observed (P = 0.039). In young and older patients, operative arthroscopy can be useful for short-term treatment in advanced stages of internal derangement of the temporomandibular joint.

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.

Correlation between MRI-diagnosed joint effusion and demographic, clinical, imaging, and arthroscopic findings of the temporomandibular joint

Our study aimed to evaluate the diagnostic accuracy of MRI in cases of joint effusion and documented its relationship with clinical and arthroscopic findings. A cross-sectional study was carried out, using the following selection criteria: clinical, radiological, and MRI-based diagnosis of joint pathology; joint pain; and indication for minimally invasive management with arthroscopy. Arthroscopic analysis, included synovitis, adhesions, chondromalacia, and disc perforations. These variables were recorded and compared with MRI findings of effusion. Data were analyzed using chi-square and Fisher's exact tests. In total, 44 temporomandibular joints were studied, of which 38 corresponded to women; 21 cases were diagnosed as Wilkes IV-V, with effusion found in all of them. The presence of effusion was significantly related to synovitis (p = 0.031) and adherences (p = 0.042). Pain was significantly related to the presence of effusion (p = 0.002), Wilkes advanced stages (p = 0.006), synovitis (p = 0.031), and adherences (p = 0.004). Regarding maximum mouth opening, there was no significant correlation with the variables studied, aside from gender and Wilkes classification. There was a significant correlation between the presence of joint effusion detected by MRI and clinical and arthroscopic findings. This suggests that effusion diagnosed by magnetic resonance has a significant value. Therefore, an adequate presurgical examination should be considered before submitting the patient to an invasive diagnostic procedure.