Effects of intra-articular administration of sodium hyaluronate on plasminogen activator system in temporomandibular joints with osteoarthritis

Comparison of Four Treatment Protocols with Intra-Articular Medium Molecular Weight Hyaluronic Acid in Induced Temporomandibular Osteoarthritis: An Experimental Study

The aim was to compare the effect between a single intra-articular infiltration (1i) and two infiltrations (2i) of medium molecular weight hyaluronic acid (MMW-HA) of high viscosity (HV) and low viscosity (LV) on the histopathological characteristics of temporomandibular joint (TMJ) osteoarthritis (OA) induced in rabbits. An experimental study was conducted on Oryctolagus cuniculus rabbits, including 42 TMJs, distributed between (1) TMJ-C, control group; (2) TMJ-OA, group with OA; (3) TMJ-OA-wt, group with untreated OA; (4) group treated with HA-HV-1i; (5) group treated with HA-HV-2i; (6) group treated with HA-LV-1i; and (7) group treated with HA-LV-2i. The results were evaluated using the Osteoarthritis Research Society International (OARSI) scale and descriptive histology considering the mandibular condyle (MC), the articular disc (AD), and the mandibular fossa (MF). The Kruskal-Wallis test was used for the statistical analysis, considering p < 0.05 significant. All treated groups significantly decreased the severity of OA compared to the TMJ-OA-wt group. The HA-HV-2i group showed significant differences in the degree of OA from the TMJ-OA group. The degree of OA in the HA-HV-2i group was significantly lower than in the HA-LV-1i, HA-LV-2i, and HA-HV-1i groups. The protocol that showed better results in repairing the joint was HA-HV-2i. There are histological differences depending on the protocol of the preparation used: two infiltrations seem to be better than one, and when applying two doses, high viscosity shows better results.

Comparison between two viscosupplementation protocols for temporomandibular joint osteoarthritis

OBJECTIVE

This clinical trial aimed to compare the efficacy of two protocols using high molecular weight hyaluronic acid (HA) intra-articular injection in patients with temporomandibular joint (TMJ) osteoarthritis and evaluate involvement of subchondral bone changes and psychosocial factors as predictors of HA treatment.

METHODS

Twenty-one individuals were divided into two groups: (A) received three intra-articular HA injections, and (B) received one injection. Outcomes observed were pain intensity, functional limitation, maximum voluntary mouth opening, maximum assisted mouth opening, and treatment tolerability. Follow-ups were performed weekly for 21 days, and two months after the treatment started.

RESULTS

No statistically significant intergroup differences were observed in any of the evaluated outcomes. However, Group A showed significant improvement in all outcomes, whereas Group B showed significant improvement only in pain intensity and functional limitation.

CONCLUSION

This study demonstrated the effectiveness of both protocols in terms of pain intensity and functional limitation caused by osteoarthritis.

EFFECTIVENESS OF INTRA-ARTICULAR INJECTIONS OF SODIUM HYALURONATE, CORTICOSTEROIDS, PLATELET-RICH PLASMA ON TEMPOROMANDIBULAR JOINT OSTEOARTHRITIS: A SYSTEMATIC REVIEW AND NETWORK META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

OBJECTIVE

To compare the efficacy of Intra-articular injections of corticosteroids (CCS), hyaluronic acid (HA), and platelet-rich plasma (PRP) on temporomandibular joint osteoarthritis.

METHODS

Studies were identified from PubMed, Embase and Cochrane Central Register of Controlled Trials, ClinicalTrials.gov with date up to January 15, 2022. Randomized controlled trials included were the studies of patients with temporomandibular joint osteoarthritis who had intra-articular treatment with CCS, HA, PRP, placebo and follow-up assessing temporomandibular joint function in target outcome variables. The primary outcome was temporomandibular joint pain. The secondary outcomes were maximal mouth opening (mm), and lateral movement to the affected side (mm). This study is registered with PROSPERO, number CRD42021270914.

RESULTS

Nine randomized controlled trials involving 316 patients were included. For primary pain outcome, no significance was detected when CCS, HA and PRP were compared with placebo by both short- (3-6 months) and long-term (>12 months) follow-up. Relatively, the top ranking of which was PRP in the long-term (Mean Difference, -0.23 [95% CI, -2.49 to 2.04]). In addition, these injectables did not significantly outperform placebo by evaluating secondary functional outcomes (maximal mouth opening and lateral movement) with the same follow-up. Subgroup analyses showed that the effect of CCS on subgroups with more than 70% women was statistically less effective compared with placebo (Mean Difference, 1.73 [95% CI, 0.37-3.09]).

CONCLUSION

Evidence suggested that intra-articular pharmacological injections of CCS, HA, and PRP had no effect on improving temporomandibular joint pain and functional outcomes compared with placebo injection.

Changes in serum angiogenic factors among patients with acute pain and subacute pain

Screening serum biomarkers for acute and subacute pain is important for precise pain management. This study aimed to examine serum levels of angiogenic factors in patients with acute and subacute pain as potential biomarkers. Serum samples were collected from 12 healthy controls, 20 patients with postherpetic neuralgia (PHN), 4 with low back pain (LBP), and 1 with trigeminal neuralgia (TN). Pain intensity in these patients was evaluated using the visual analog scale (VAS). The serum concentrations of 11 angiogenic biomarkers were examined by Milliplex Map Human Angiogenesis Magnetic Bead Panel 2. The pain assessment from VAS showed that all patients showed moderate and severe pain. Among 11 angiogenic factors, osteopontin (OPN), thrombospondin-2 (TSP-2), soluble platelet endothelial cell adhesion molecule-1 (sPECAM-1), soluble urokinase-type plasminogen activator receptor (suPAR), and soluble epidermal growth factor receptors (sErbB2) were up-regulated and soluble interleukin-6 receptor α (sIL-6Rα) were down-regulated in patients with pain compared to the healthy participants (all P-values were < 0.005). Moreover, a linear regression model showed that the serum OPN concentration was correlated with pain intensity in patients with PHN (P = 0.03). There was no significant difference between the serum concentration of soluble epidermal growth factor receptors, sErbB3, soluble AXL, tenascin, and soluble neuropilin-1 in patients with acute and subacute pain and that of healthy controls. The results of this study provided new valuable insights into our understanding of angiogenic factors that may contribute to as mechanistic biomarkers of pain, and reveal the pathophysiological mechanism of pain.

Clinical Trial Registration:www.chictr.org.cn, identifier ChiCTR2200061775.

Action of Hyaluronic Acid as a Damage-Associated Molecular Pattern Molecule and Its Function on the Treatment of Temporomandibular Disorders

The temporomandibular joint is responsible for fundamental functions. However, mechanical overload or microtraumas can cause temporomandibular disorders (TMD). In addition to external factors, it is known that these conditions are involved in complex biological mechanisms, such as activation of the immune system, activation of the inflammatory process, and degradation of extracellular matrix (ECM) components. The ECM is a non-cellular three-dimensional macromolecular network; its most studied components is hyaluronic acid (HA). HA is naturally found in many tissues, and most of it has a high molecular weight. HA has attributed an essential role in the viscoelastic properties of the synovial fluid and other tissues. Additionally, it has been shown that HA molecules can contribute to other mechanisms in the processes of injury and healing. It has been speculated that the degradation product of high molecular weight HA in healthy tissues during injury, a low molecular weight HA, may act as damage-associated molecular patterns (DAMPs). DAMPs are multifunctional and structurally diverse molecules that play critical intracellular roles in the absence of injury or infection. However, after cellular damage or stress, these molecules promote the activation of the immune response. Fragments from the degradation of HA can also act as immune response activators. Low molecular weight HA would have the ability to act as a pro-inflammatory marker, promoting the activation and maturation of dendritic cells, the release of pro-inflammatory cytokines such as interleukin 1 beta (IL-1β), and tumor necrosis factor α (TNF-α). It also increases the expression of chemokines and cell proliferation. Many of the pro-inflammatory effects of low molecular weight HA are attributed to its interactions with the activation of toll-like receptors (TLRs 2 and 4). In contrast, the high molecular weight HA found in healthy tissues would act as an anti-inflammatory, inhibiting cell growth and differentiation, decreasing the production of inflammatory cytokines, and reducing phagocytosis by macrophages. These anti-inflammatory effects are mainly attributed to the interaction of high-weight HA with the CD44 receptor. In this study, we review the action of the HA as a DAMP and its functions on pain control, more specifically in orofacial origin (e.g., TMD).

An updated view on Temporomandibular Joint degeneration: insights from the cell subsets of mandibular condylar cartilage

The high prevalence of temporomandibular joint osteoarthritis (TMJOA), which causes joint dysfunction, indicates the need for more effective methods for treatment and repair. Mandibular condylar cartilage (MCC), a typical fibrocartilage that experiences degenerative changes during the development of TMJOA, has become a research focus and therapeutic target in recent years. MCC is composed of four zones of cells at various stages of differentiation. The cell subsets in MCC exhibit different physiological and pathological characteristics during development and in TMJOA. Most studies of TMJOA are mainly concerned with gene regulation of pathological changes. The corresponding treatment targets with specific cell subsets in MCC may provide more accurate and reliable results for cartilage repair and TMJOA treatment. In this review, we summarized the current research progress on the cell subsets of MCC from the perspective of MCC development and degeneration. We hope to provide a reference for further exploration of the pathological process of TMJOA and improvement of TMJOA treatment.

Mechanisms of Action and Efficacy of Hyaluronic Acid, Corticosteroids and Platelet-Rich Plasma in the Treatment of Temporomandibular Joint Osteoarthritis-A Systematic Review

Temporomandibular joint osteoarthritis (TMJ OA) is a low-inflammatory disorder with multifactorial etiology. The aim of this review was to present the current state of knowledge regarding the mechanisms of action and the efficacy of hyaluronic acid (HA), corticosteroids (CS) and platelet-rich plasma (PRP) in the treatment of TMJ OA.: The PubMed database was analyzed with the keywords: "(temporomandibular joint) AND ((osteoarthritis) OR (dysfunction) OR (disorders) OR (pain)) AND ((treatment) OR (arthrocentesis) OR (arthroscopy) OR (injection)) AND ((hyaluronic acid) OR (corticosteroid) OR (platelet rich plasma))". After screening of 363 results, 16 studies were included in this review. Arthrocentesis alone effectively reduces pain and improves jaw function in patients diagnosed with TMJ OA. Additional injections of HA, either low-molecular-weight (LMW) HA or high-molecular-weight (HMW) HA, or CS at the end of the arthrocentesis do not improve the final clinical outcomes. CS present several negative effects on the articular cartilage. Results related to additional PRP injections are not consistent and are rather questionable. Further studies should be multicenter, based on a larger group of patients and should answer the question of whether other methods of TMJ OA treatment are more beneficial for the patients than simple arthrocentesis.

TMJ arthroscopy with hyaluronic acid: A 12-month randomized clinical trial

OBJECTIVES

To determine the effects of hyaluronic acid (HA) as an adjunct to temporomandibular joint (TMJ) arthroscopy, relative to standard TMJ arthroscopy, in Wilkes stage-III and stage-IV patients.

METHODS

A randomized clinical trial design was utilized (ClinicalTrials.gov NCT04110587). 51 patients were allocated to a TMJ arthroscopy (n = 25) or a TMJ arthroscopy plus HA (n = 26) group. Visual analog scale joint pain scores, maximum mouth opening (MMO), and muscle pain were measured at baseline, and at 3, 6, 9, and 12 months. Disk position on magnetic resonance imaging was evaluated at baseline and 12 months. Oral health-related quality of life (OHRQoL) was assessed at baseline, and at 6 and 12 months.

RESULTS

No group differences were observed in clinical or radiographic measurements (p ≥ .05). The results do not indicate any benefit of HA as an adjuvant therapy to arthroscopy during follow-up months 3-12. TMJ arthroscopy improved OHRQoL at 6 and 12 months (Oral Health Impact Profile-14 questionnaire scores of -14.59 and -14.27, 95% confidence intervals = -17.55 to -11.63 and -17.27 to -11.27) respectively, as well as pain and MMO, at all follow-up time points (p < .001).

CONCLUSIONS

A beneficial effect of HA injection during TMJ arthroscopy after the 3-month follow-up was not observed.

Arthrocentesis and Sodium Hyaluronate Infiltration in Temporomandibular Disorders Treatment. Clinical and MRI Evaluation

Arthrocentesis in temporomandibular joint disorders can be associated with the intra-articular infiltration of various drugs with the objective of increase treatment efficacy. The aim of this study was to evaluate the clinical indexes variation in patients affected by temporomandibular joint disorders treated with arthrocentesis and sodium hyaluronate (SH) injections. A total of 28 patients suffering from temporomandibular joint disorders underwent one cycle of five arthrocentesis and infiltrations of sodium hyaluronate. Spontaneous mouth opening improved from 36.3 ± 7.5 mm to 45.1 ± 1.9 mm at six months follow-up. A significant reduction in the pain at rest and during mastication mean values emerged at follow-up (p < 0.0001). The mean masticatory efficiency, evaluated through a visual analogic scale, showed improvement at the follow-up period, highlighted by the increase of mean value from a baseline of 3.1 ± 1.2 to a mean value of 8.5 ± 1.2 (p < 0.0001). The mean severity of the joint damage at baseline time was 2.4 ± 0.9 and decreased to 0.4 ± 0.3 at the end of the follow-up period. The decrease in values is confirmed by statistical test (p < 0.05). Our data show how arthrocentesis integrated with sodium hyaluronate infiltrations performed under local anesthesia is a valid method of treating temporomandibular joint disorders.

Efficacy of viscosupplementation with hyaluronic acid in temporomandibular disorders: A systematic review

OBJECTIVE

To perform a systematic review of the viscosupplementation effectiveness with hyaluronic acid (HA) in the articular Temporomandibular Dysfunctions (TMDs) clinical management.

METHOD

Electronic searches were performed in the following databases: MEDLINE (via PubMed), Scopus, Web of Science, Cochrane Library, EMBASE, LILACS, BBO, SIGLE (System for Information on Grey Literature in Europe), ClinicalTrials.gov, and the Brazilian Clinical Trials Registry (ReBec). Only randomized clinical trials that evaluated the intra-articular administration of HA or its derivatives in osteoarthritis and/or anterior displacement of the temporomandibular joint (TMJ) disc were included. The primary outcomes evaluated were patients' self-report of pain and/or discomfort in the TMJ. Each study was assessed for the risk of bias, using the Cochrane collaboration's risk of bias tool.

RESULTS

A total of 640 studies were obtained in the electronic search. After the application of the eligibility criteria, manual search, and duplicate removal, 21 articles were included. Five articles classified their volunteers with internal derangements of the TMJ, in 4 articles the treatment was directed to participants with disc displacement with reduction and the other articles evaluated HA therapy in osteoarthritis. The protocols presented heterogeneity, varying in the form of application, associated or not with arthrocentesis, number of applications, molecular weight, dose and concentration. Nine studies presented high risk of bias.

CONCLUSION

Due to the heterogeneity and methodological inconsistencies of the studies evaluated, it was not possible to establish the efficacy of HA in articular TMDs.

Clinical Outcome of Sodium Hyaluronate Injection into the Superior and Inferior Joint Space for Osteoarthritis of the Temporomandibular Joint Evaluated by Cone-Beam Computed Tomography: A Retrospective Study of 51 Patients and 56 Joints

BACKGROUND The aim of this study was to determine the clinical effects of sodium hyaluronate injection into the superior and inferior joint space for osteoarthritis of the temporomandibular joint (TMJ) and to evaluate the joint changes using cone-beam computed tomography (CBCT). MATERIAL AND METHODS A retrospective observational clinical study included 51 patients and 56 TMJs, with a diagnosis of osteoarthritis. All patients received sodium hyaluronate injections into the superior and inferior TMJ joint spaces (articular cavities). At baseline and post-treatment the condylar bony changes were evaluated by CBCT. To evaluate TMJ function, maximum mouth opening (MMO), and Helkimo's index was used, which included an anamnestic index (Ai) and a clinical dysfunction index (Di). Patients were divided into short-term (one year) follow-up groups. RESULTS In both patient follow-up groups, sodium hyaluronate injection of the superior and inferior TMJ space significantly improved MMO, the Ai, and the Di (P<0.05). There were no significant differences between the two groups in condylar bony changes of the TMJ seen by CBCT (sclerosis, erosion, hyperplasia, and flattening) (P>0.05). CBCT showed a good predictive ability on post-treatment symptom relief following sodium hyaluronate injection into the superior and inferior TMJ space in patients with osteoarthritis of the TMJ (P=0.024). CONCLUSIONS The findings of this clinical and CBCT imaging study showed that sodium hyaluronate injection into the superior and inferior TMJ space in patients with osteoarthritis improved clinical symptoms, but did not control the progression of osteoarthritic joint destruction.

Effect of hyaluronic acid on the regulation of inflammatory mediators in osteoarthritis of the temporomandibular joint: a systematic review

Osteoarthritis is one of the most frequent pathologies affecting the temporomandibular joint (TMJ). There is evidence that the use of intra-articular hyaluronic acid (HA) for the treatment of this disorder achieves positive effects through a reduction in inflammatory mediators. A systematic review of the available evidence regarding the regulation of inflammatory mediators when applying HA in osteoarthritis of the TMJ in humans was performed. The Web of Science, Embase, ScienceDirect, MEDLINE, Scopus, EBSCOhost, and LILACS databases, SciELO library, and search engine Trip Database were searched systematically. Two thousand eight hundred and sixty-three related articles were found, of which only two met the selection criteria (both were clinical trials and evidence level 2b for treatment studies). These two articles represented a population of 87 patients. Both articles reported that the application of HA had a positive effect on the regulation of inflammatory mediators; the mediators studied were those of the plasminogen activator system and levels of nitric oxide. The limited evidence available suggests that the application of HA regulates various inflammatory mediators in osteoarthritic processes in the TMJ. Nevertheless, further evidence in this regard is required, through the study of specific pathologies of the TMJ, complementing the assessment of clinical parameters with molecular studies, and generating good quality clinical studies with larger sample sizes.

Current understanding of pathogenesis and treatment of TMJ osteoarthritis

Osteoarthritis is a common disease that can cause severe pain and dysfunction in any joint, including the temporomandibular joint (TMJ). TMJ osteoarthritis (TMJOA) is an important subtype in the classification of temporomandibular disorders. TMJOA pathology is characterized by progressive cartilage degradation, subchondral bone remodeling, and chronic inflammation in the synovial tissue. However, the exact pathogenesis and process of TMJOA remain to be understood. An increasing number of studies have recently focused on inflammation and remodeling of subchondral bone during the early stage of TMJOA, which may elucidate the possible mechanism of initiation and progression of TMJOA. The treatment strategy for TMJOA aims at relieving pain, preventing the progression of cartilage and subchondral bone destruction, and restoring joint function. Conservative therapy with nonsteroidal anti-inflammatory drugs, splint, and physical therapy, such as low-energy laser and arthrocentesis, are the most common treatments for TMJOA. These therapies are effective in most cases in relieving the signs and symptoms, but their long-term therapeutic effect on the pathologic articular structure is unsatisfactory. A treatment that can reverse the damage of TMJOA remains unavailable to date. Treatments that prevent the progression of cartilage degradation and subchondral bone damage should be explored, and regeneration for the TMJ may provide the ideal long-term solution. This review summarizes the current understanding of mechanisms underlying the pathogenesis and treatment of TMJOA.

Soluble urokinase plasminogen activator receptor--a valuable biomarker in systemic lupus erythematosus?

Systemic lupus erythematosus (SLE) is a potentially severe autoimmune condition with an unpredictable disease course, often with fluctuations in disease activity over time. Long term inflammation and drug-related side-effects may subsequently lead to permanent organ damage, a consequence which is intimately connected to decreased quality of life and mortality. New lupus biomarkers that convey information regarding inflammation and/or organ damage are thus warranted. Today, there is no clinical biomarker that indicates the risk of damage accrual. Herein we highlight the urokinase plasminogen activator receptor (uPAR) and especially its soluble form (suPAR) that besides having biological functions in e.g. proteolysis, cell migration and tissue homeostasis, recently has emerged as a promising biomarker of inflammation and prognosis of several disorders. A strong association between suPAR and organ damage in SLE was recently demonstrated, and preliminary data (presented in this review) suggests the possibility of a predictive value of suPAR blood levels. The involvement of suPAR in the pathogenesis of SLE remains obscure, but its effects in leukocyte recruitment, phagocytic uptake of dying cells (efferocytosis) and complement regulation suggests that the central parts of the SLE pathogenesis could be regulated by suPAR, and vice versa.

Urokinase plasminogen activator system in synovial fibroblasts from osteoarthritis patients: modulation by inflammatory mediators and neuropeptides

Plasminogen activators are specific proteolytic enzymes implicated in a variety of basic biological processes. The expression of the urokinase plasminogen activator system components is increased in some human diseases, including osteoarthritis. We sought to study the effect of two components of the inflamed synovial microenvironment on this system, IL-1β and fibronectin fragments, elucidating whether corticotropin-releasing factor (CRF) and vasoactive intestinal peptide (VIP) neuropeptides modulate it, and analyzing the physiological consequences in joint destruction by measuring matrix metalloproteinases-9 and metalloproteinases-13 levels in osteoarthritis fibroblast-like synoviocytes. We showed that IL-1β and fibronectin fragments stimulated urokinase system contributing to the perpetuation of the destructive cascade in joint. VIP modulated, even at constitutive level, this system, also counteracting the effect of both inflammatory stimuli. However, CRF seemed to be ineffective in controlling the production of these proteinases. Moreover, VIP was able to reduce the constitutive expression of matrix metalloproteinase-13 and the levels of both matrix metalloproteinases after stimulation with the pro-inflammatory stimuli. Our results suggest that the presence of early and later inflammatory mediators, such as IL-1β and fibronectin fragments, increases the urokinase system and the matrix metalloproteinases levels. Whereas CRF did not affect this system, VIP counteracts these actions supporting its therapeutic potential for the treatment of osteoarthritis.

Shear stress modulates macrophage-induced urokinase plasminogen activator expression in human chondrocytes

Introduction

Synovial macrophages, which can release proinflammatory factors, are responsible for the upregulation of cartilage-breakdown proteases and play critical roles in cartilage degradation during the progression of osteoarthritis (OA). In addition, shear stress exerts multifunctional effects on chondrocytes by inducing the synthesis of catabolic or anabolic genes. However, the interplay of macrophages, chondrocytes, and shear stress during the regulation of cartilage function remains poorly understood. We investigated the mechanisms underlying the modulation of human chondrocyte urokinase plasminogen activator (uPA) expression by macrophages and shear stress.

Methods

Human chondrocytes were stimulated by peripheral blood-macrophage- conditioned medium (PB-MCM), or exposure of chondrocytes cultured in PB-MCM to different levels of shear stress (2 to 20 dyn/cm²). Real-time polymerase chain reaction was used to analyze uPA gene expression. Inhibitors and small interfering RNA were used to investigate the mechanism for the effects of PB-MCM and shear stress in chondrocytes.

Results

Stimulation of human chondrocytes with PB-MCM was found to induce uPA expression. We demonstrated that activation of the JNK and Akt pathways and NF-κB are critical for PB-MCM-induced uPA expression. Blocking assays by using IL-1ra further demonstrated that IL-1β in PB-MCM is the major mediator of uPA expression in chondrocytes. PB-MCM-treated chondrocytes subjected to a lower level of shear stress showed inhibition of MCM-induced JNK and Akt phosphorylation, NF-κB activation, and uPA expression. The PB-MCM-induced uPA expression was suppressed by AMP-activated protein kinase (AMPK) agonist. The inhibitor or siRNA for AMPK abolished the shear-mediated inhibition of uPA expression.

Conclusions

These data support the hypothesis that uPA upregulation stimulated by macrophages may play an active role in the onset of OA and in the shear-stress protection against this induction.

Interventions for the management of temporomandibular joint osteoarthritis

BACKGROUND

Osteoarthritis (OA) is the most common form of arthritis of the temporomandibular joint (TMJ), and can often lead to severe pain in the orofacial region. Management options for TMJ OA include reassurance, occlusal appliances, physical therapy, medication in addition to several surgical modalities.

OBJECTIVES

To investigate the effects of different surgical and non-surgical therapeutic options for the management of TMJ OA in adult patients.

SEARCH METHODS

We searched the following databases: the Cochrane Oral Health Group Trials Register (to 26 September 2011); CENTRAL (The Cochrane Library 2011, Issue 3); MEDLINE via OVID (1950 to 26 September 2011); EMBASE via OVID (1980 to 26 September 2011); and PEDro (1929 to 26 September 2011). There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing any form of non-surgical or surgical therapy for TMJ OA in adults over the age of 18 with clinical and/or radiological diagnosis of TMJ OA according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) guideline or compatible criteria.Primary outcomes considered were pain/tenderness/discomfort in the TMJs or jaw muscles, self assessed range of mandibular movement and TMJ sounds. Secondary outcomes included the measurement of quality of life or patient satisfaction evaluated with a validated questionnaire, morphological changes of the TMJs assessed by imaging, TMJ sounds assessed by auscultation and any adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors screened and extracted information and data from, and independently assessed the risk of bias in the included trials.

MAIN RESULTS

Although three RCTs were included in this review, pooling of data in a meta-analysis was not possible due to wide clinical diversity between the studies. The reports indicate a not dissimilar degree of effectiveness with intra-articular injections consisting of either sodium hyaluronate or corticosteroid preparations, and an equivalent pain reduction with diclofenac sodium as compared with occlusal splints. Glucosamine appeared to be just as effective as ibuprofen for the management of TMJ OA.

AUTHORS' CONCLUSIONS

In view of the paucity of high level evidence for the effectiveness of interventions for the management of TMJ OA, small parallel group RCTs which include participants with a clear diagnosis of TMJ OA should be encouraged and especially studies evaluating some of the possible surgical interventions.