Identification of prostaglandin E2 and leukotriene B4 in the synovial fluid of painful, dysfunctional temporomandibular joints

Comparative effectiveness of hyaluronic acid, platelet-rich plasma, and platelet-rich fibrin in treating temporomandibular disorders: a systematic review and network meta-analysis

OBJECTIVE

This study aims to compare the efficacy of intra-articular injections of hyaluronic acid (HA), platelet-rich plasma (PRP), and platelet-rich fibrin (PRF) for treating temporomandibular disorders (TMDs) and summarize their mechanisms of action.

METHODS

Randomized controlled trials (RCTs) published until November 13, 2021, were identified using electronic and manual searches. Each study was evaluated for the risk of bias using the Cochrane risk of bias tool. The studies found via searches were categorized by follow-up time (1, 3, or 6 months). Evidence quality was graded according to the GRADE system.

RESULTS

Twelve RCTs were included that involved 421 patients with TMD. The network meta-analysis showed that all treatment groups improved compared to the placebo groups in terms of pain and maximal mouth opening (MMO). For pain evaluated via the visual analog scale, PRF exhibited better analgesic effects than PRP or HA after 1 and 3 months. PRP appeared to be more effective than PRF was after 6 months but there were no statistically significant differences between the two. For MMO, the effect of PRP was superior to those of PRF and HA after 1 month. However, after 3 and 6 months, PRF provided more encouraging results in improving MMO.

CONCLUSION

PRP and PRF exhibited similar short-term efficacy in treating TMD, while PRF was more advantageous in terms of long-term efficacy. Therefore, PRF was recommended for treating TMD.

Intra-articular injection of hyaluronic acid versus platelet-rich plasma following single puncture arthrocentesis for the management of internal derangement of TMJ: A double-blinded randomised controlled trial

The present study aimed to compare the efficacies of intra-articular injections of platelet-rich plasma (PRP) and hyaluronic acid (HA) following single needle arthrocentesis in patients with TMJ internal derangement. This double-blinded randomised controlled trial involved the enrolment of patients diagnosed with unilateral TMD, falling into either Wilkes' stages II or III. In Group A, single needle arthrocentesis was performed using Ringer's lactate serving as a control group; in Group B, intra-articular injection of 1 ml hyaluronic acid injection was given following arthrocentesis; and in Group C, autologous intraarticular injections of 1 ml of PRP was given after arthrocentesis, twice in two weeks' interval. The primary outcome variables were maximum mouth opening and pain, while TMJ clicking sounds formed the secondary outcome variable. All the outcome variables were assessed preoperatively (T0) and postoperatively after the second dose of injection at one month (T1), three months (T2), and six months (T3). The alpha level was set to p < 0.05. Ninety patients (N = 90) comprised the final sample size of the study with thirty patients(n = 30) in each treatment group. A statistically significant decrease in the management in mean pain scores was noted between T0 [mean scores were 7.30 ± 1.05 (Group A), 7.63 ± 1.12 (Group B), and 7.56 ± 1.04(Group C)] and T3 [mean scores were 2.66 ± 0.88 (Group A), 2.4 ± 0.72 (Group B), and 1.66 ± 0.66 (Group C)] time intervals between Group A and C(p < 0.001). Significant improvement was noted in preoperative maximum mouth opening (MMO) of Group A, B, and C which was 22.83 ± 3.58, 22.17 ± 4.07, and 21.37 ± 3.69, respectively to 28.90 ± 2.72, 32.17 ± 3.97, and 34.10 ± 3.80 mm, respectively at six months postoperatively (p < 0.001). A significant decrease in joint sounds was evident for all three groups(p = 0.003 for Group A, p < 0.001 for Group B, and p < 0.001 for Group C) across the time intervals. Moreover, Group C showed a significant decrease in the prevalence of joint sound compared to the other two groups at all-time intervals postoperatively when equated to baseline (p = 0.02 at T1, p = 0.009 at T2, and p = 0.002 at T3). Within the limitations of the present study, it can be concluded that intra-articular PRP may be preferable over HA whenever appropriate, following single needle arthrocentesis in the treatment of TMJ internal derangement.

940 nm diode laser induced differentiation of human adipose derived stem cells to temporomandibular joint disc cells

Background

Temporomandibular disorder (TMD) refers to a group of disorders that affect temporomandibular joint (TMJ) and its associated muscles with very limited treatment options. Stem cell research is emerging as one of the promising fields in the treatment of degenerative diseases. The ability of human adipose derived stem cells to differentiate into many cell types is driving special interest in several disease management strategies. Photobiomodulation has enhanced the role of these stem cells through their ability to promote cell proliferation and differentiation. Hence, this study examined the differentiation potential of human adipose derived stem cells (ADSCs) into fibroblasts and chondrocytes using a 940 nm diode laser for possible TMD therapy.

Materials and methods

ADSCs were cultured at different seeding densities and for different time intervals. After irradiation at 24, 48, 72 h, 1, 2 and 3 weeks, ADSC viability and morphological changes were assessed in groups with and without basic fibroblast growth factor. Additionally, the level of adenosine triphosphate (ATP) in the cells was also recorded. The differentiated fibroblasts and chondrocytes were characterized with flow cytometry and immunofluorescence techniques, at 1- and 2-weeks post-irradiation.

Results

Increased ATP proliferation and cell viability above 90% were observed in all post-irradiation experimental groups. Post irradiation results from flow cytometry and immunofluorescence at 1- and 2‐weeks confirmed the expression of chondrogenic and fibroblastic cell surface markers.

Conclusion

This study describes stimulatory techniques utilized to differentiate ADSCs into fibroblastic and chondrogenic phenotypes using diode lasers at 940 nm. The study proposes a new treatment model for patients with degenerative disc diseases of the TMJ. The study will offer new possibilities in tissue engineering and TMJ disc management through photobiomodulation of ADSCs using a 940 nm diode laser.

Correlation of arthroscopic findings with clinical-radiological signs and symptoms of temporomandibular joint dysfunction: retrospective study of 829 joints

Temporomandibular joint (TMJ) arthroscopic findings are difficult to predict based on clinical criteria. Few studies have attempted to correlate signs, symptoms, and characteristics of patients with the final arthroscopic findings. The aim of this study was to assess the correlation between clinical-radiological signs and symptoms and arthroscopic findings in patients with TMJ dysfunction undergoing arthroscopy. A retrospective study was performed involving 487 patients (829 joints) with TMJ dysfunction who underwent TMJ arthroscopy between 2000 and 2019. The clinical-radiological variables recorded were pain, maximum mouth opening, joint noises, Wilkes classification, and disc displacement. The arthroscopic findings evaluated were synovitis, chondromalacia, adhesions, disc perforation, disc displacement, and roofing. Pain symptoms were significantly associated with the intensity of synovitis (P = 0.005) and disc displacement evaluated arthroscopically (P < 0.001). A statistically significant relationship was observed between Wilkes stage and the level of synovitis (P < 0.001) and chondromalacia (P < 0.001). Mouth opening was negatively correlated with adhesions (P < 0.001). Based on this study, pain symptomatology was associated with the intensity of synovitis and disc displacement evaluated arthroscopically, the Wilkes stage was a good predictor of the severity of synovitis and chondromalacia, and mouth opening was negatively correlated with adhesions.

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.

Understanding Early-Stage Posttraumatic Osteoarthritis for Future Prospects of Diagnosis: from Knee to Temporomandibular Joint

PURPOSE OF REVIEW

Many mechanical load-bearing joints of the body are prone to posttraumatic osteoarthritis (PTOA), including the knee joint and temporomandibular joint (TMJ). Early detection of PTOA can be beneficial in prevention or alleviating further progression of the disease.

RECENT FINDINGS

Various mouse models, similar to those used in development of novel diagnosis strategies for early stages of OA, have been proposed to study early PTOA. While many studies have focused on OA and PTOA in the knee joint, early diagnostic methods for OA and PTOA of the TMJ are still not well established. Previously, we showed that fluorescent near-infrared imaging can diagnose inflammation and cartilage damage in mouse models of knee PTOA. Here we propose that the same approach can be used for early diagnosis of TMJ-PTOA. In this review, we present a brief overview of PTOA, application of relevant mouse models, current imaging methods available to examine TMJ-PTOA, and the prospects of near-infrared optical imaging to diagnose early-stage TMJ-OA.

Laser-Induced Differentiation of Human Adipose-Derived Stem Cells to Temporomandibular Joint Disc Cells

BACKGROUND AND OBJECTIVES

Temporomandibular disorder (TMD) is an incapacitating disease with temporomandibular joint (TMJ) disc degenerative changes in patients. Despite several research attempts to find a definitive treatment, there is no evidence of a permanent solution. The objective of the current study was to observe the role of 660 nm diode laser in the differentiation of human adipose-derived stem cells (ADSCs) to fibroblasts and chondrocytes.

STUDY DESIGN/MATERIALS AND METHODS

After irradiation, the morphology, viability, and adenosine triphosphate (ATP) proliferation of the ADSCs were analyzed at different time intervals. The differentiation of ADSCs toward fibroblastic and chondrogenic phenotypes was supported using flow cytometry and immunofluorescence at 1- and 2-week post-irradiation.

RESULTS

More than 90% of viable cells were observed in all experimental groups, with an increase in ATP proliferation. Flow cytometry analyses and immunofluorescence demonstrated the presence of chondrogenic and fibroblastic cell surface markers at 1- and 2-week post-irradiation.

CONCLUSION

This study has demonstrated methods to induce the differentiation of ADSCs toward fibroblastic and chondrogenic phenotypes with a 660 nm diode laser. The study also proposes a future alternative method of treatment for patients with degenerative TMJ disc disorders and presents a positive prospect in the application of photobiomodulation and ADSCs in the treatment of degenerative TMJ disc. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Photobiomodulation and Stem Cell Therapy for Temporomandibular Joint Disc Disorders

Background: Temporomandibular disorder (TMD) refers to a group of disorders affecting the temporomandibular joint (TMJ) and its related muscles. The two commonly used treatment modalities for TMD are occlusal splint therapy and relaxation therapy. Neither comprises definitive treatment. Objective: The objective of this review was to report updated information on photobiomodulation and stem cells, as an alternative treatment for the degenerative TMJ disc as a part of TMJ disorders. Materials and methods: With only a few research studies reported till date, this review also proposes the mechanism of laser irradiation on inflammatory mediators to treat TMD. Results: Photobiomodulation of stem cells with and without scaffolds could be used indirectly or directly as modulation of degenerative changes of the TMJ disc. Conclusions: The need for a distinct shift of the research margin in this field of dentistry is evident, specifically regarding the application of photobiomodulation and stem cells for tissue engineering of the TMJ disc.

Analysis of synovial fluid visfatin level in temporomandibular joint disorders

Background: Biochemical analysis of synovial fluid (SF) is an important means of understanding the pathogenesis of temporomandibular disorder (TMD) and confirming diagnoses made using traditional methods. Objective: The aim of this study was to determine whether or not SF visfatin levels can serve as a biochemical marker in the diagnosis of TMD. Method: Sixty samples of SF were obtained from 60 patients with internal derangement (ID) or osteoarthritis (OA). Visfatin in the SF was examined by enzyme-linked immunosorbent assay (ELISA). Result: Visfatin levels showed positive correlations with TMD pain and ID stage and a negative correlation with maximum mouth opening. In addition, Visfatin levels in joints with OA changes in the condyle were significantly higher in comparison to joints with no OA changes. Conclusion: Within the limitations of this study, it can be concluded that visfatin may play a role in the pathogenesis of TMD.

Regulation of inflammation by lipid mediators in oral diseases

Lipid mediators (LM) of inflammation are a class of compounds derived from ω-3 and ω-6 fatty acids that play a wide role in modulating inflammatory responses. Some LM possess pro-inflammatory properties, while others possess proresolving characteristics, and the class switch from pro-inflammatory to proresolving is crucial for tissue homeostasis. In this article, we review the major classes of LM, focusing on their biosynthesis and signaling pathways, and their role in systemic and, especially, oral health and disease. We discuss the detection of these LM in various body fluids, focusing on diagnostic and therapeutic applications. We also present data showing gender-related differences in salivary LM levels in healthy controls, leading to a hypothesis on the etiology of inflammatory diseases, particularly Sjögren's syndrome. We conclude by enumerating open areas of research where further investigation of LM is likely to result in therapeutic and diagnostic advances.

The Efficacy of Platelets Rich Plasma Injection in the Superior Joint Space of the Tempromandibular Joint Guided by Ultra Sound in Patients with Non-reducing Disk Displacement

OBJECTIVE

The objective of this study was to determine average improvement during the rest and active mouth opening after ultrasound guided platelets rich plasma injection in the tempromandibular superior joint space for the patients complaining from non-reducing disk displacement.

PATIENTS AND METHODS

Thirty-four patients with non-reducing disk displacement underwent guided ultrasound injection of platelet rich plasma to the upper joint space. The extent of maximal mouth opening, chewing efficiency, sound intensity of the TMJ, and tenderness of the TMJ and the masticatory muscles at rest, motion and mastication were thoroughly assessed at the beginning of the study and scheduled for next follow-up at 1st, 3rd, and 6th months.

RESULTS

Injection with platelets rich plasma was significantly more effective in improvements of the extent of maximal mouth opening, statistics result demonstrated a significant reduction in the VAS values of pain at rest, motion and mastication compared to the baseline VAS values.

CONCLUSION

PRP injection to the upper temporomandibular joint space provided improvement in signs and symptoms of patient with non-reducing disk displacement of the temporomandibular joint.

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.

Efficacy of Temporomandibular Joint Arthrocentesis with Sodium Hyaluronate in the Management of Temporomandibular Joint Disorders: A Prospective Randomized Control Trial

PURPOSE

This study was designed to investigate the efficacy of the temporomandibular joint arthrocentesis with and without injection of sodium hyaluronate (SH) in the treatment of temporomandibular joint disorders.

PATIENTS AND METHODS

A total of sixty two TMJs in 34 males and 28 females aged 20-65 years comprised the study material. The patients' complaints were limited mouth opening, TMJ pain, and joint noises during function. Patients were randomly divided into 2 groups in which arthrocentesis plus intra-articular injection of sodium hyaluronate was performed in 1 group and only arthrocentesis was performed in the other group. Both groups contained patients with disc displacement with reduction and without reduction. Clinical evaluation of the patients was done before the procedure, immediately after the procedure, at 1 week and 1, 3 and 6 months postoperatively. Intensity of TMJ pain was assessed using visual analog scales. Maximal mouth opening and lateral jaw movements also were recorded at each follow-up visit.

RESULTS

Both techniques increased maximal mouth opening, lateral movements, and function, while reducing TMJ pain and noise.

CONCLUSIONS

Although patients benefitted from both techniques, arthrocentesis with injection of SH seemed to be superior to arthrocentesis alone.

[Arthrocentesis of the temporomandibular joint and intra-articular injections : An update]

INTRODUCTION

Arthocentesis of the temporomandibular joint combined with intra-articular washout and, more recently, intra-articular injection of pharmacological agents has been developed from the 1990s and is nowadays extensively in use for the treatment of temporomandibular dysfunctions (TMDs). The goal of our work was to answer 3 questions: 1. Is intra-articular washout effective for the treatment of TMDs ? 2. What kind of pharmacological agents may nowadays be injected in addition to washout and are these injections useful ? 3. What is the place of these treatments in the treatment strategies of TMDs ?

MATERIAL AND METHODS

A bibliographic research has been carried out in the PubMed database using following keywords arthrocentesis, temporomandibular joint. The 27 articles published between 1991 and 2016, indicating patient's inclusion criterions and objectively evaluating the clinical results (mouth opening, intra-articular noises, pain) were selected. Pharmacological agents were noticed when used.

RESULTS

1. All authors concluded to the efficacy of intra-articular washout. No prognostic factor for arthrocentesis efficacy could be identified. 2. Main pharmacological agents used were steroids, hyaluronic acid, morphine-based drugs and platelet rich plasma. Superiority of ith-injection protocols failed to win unanimous support. All authors who compared with- and without-injection protocols concluded to the superiority of with-injection protocols, whatever the agent.

DISCUSSION

Numerous studies have proven the efficacy of intra-articular washout for the treatment of TMDs resistant to noninvasive treatments. The advantage of any kind of pharmacological agent is not clear. Mechanisms of action are not all elucidated. No pharmacological agent showed any superiority over another. Study methodologies are often defective: imprecise inclusion criterions, short follow-up, confounding variables not taken into account, few comparison between pharmacological agents.

Long-Term Outcome of Arthrocentesis Plus Hyaluronic Acid Injection in Patients With Wilkes Stage II and III Temporomandibular Joint Internal Derangement

OBJECTIVE

Arthrocentesis is a minimally invasive procedure used to manage temporomandibular joint (TMJ) internal derangement (ID). This study evaluated the outcome of arthrocentesis in patients with Wilkes stage II and III TMJ ID.

PATIENTS AND METHODS

This retrospective study enrolled 50 patients who underwent arthrocentesis in 2011 and 2012 at the Karadeniz Technical University, Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Turkey. In total, 43 patients underwent unilateral arthrocentesis, whereas 7 patients had bilateral arthrocentesis. The clinical parameters recorded were pain (visual analogue scale [VAS] 0-100 mm during movement), chewing function efficacy (VAS 0-100), clicking sounds, and mandibular movements, including maximum interincisal opening (MIO), lateral excursion, and protrusion. All the parameters were recorded preoperatively, and 1, 3, 6, and 24 months after treatment.

RESULTS

The MIO, lateral excursion, and protrusion were significantly greater than preoperatively in all the patients. Pain declined significantly postoperatively. The patients in Wilkes III group had greater improvement in mandibular movement and pain than the patients in Wilkes II group.

CONCLUSION

Arthrocentesis was reliable for treating both Wilkes II and III TMJ ID, and the treatment results were better in Wilkes III patients.

Synovial TRPV1 is upregulated by 17-β-estradiol and involved in allodynia of inflamed temporomandibular joints in female rats

Women with reproductive capability are more likely to suffer from temporomandibular disorders (TMD), with orofacial pain as the most common complaint. In the past, we focused on the role of estradiol in TMD pain through the nervous system. In this study, we explored estradiol's influence on synoviocyte gene expressions involved in the allodynia of the inflamed TMJ. The influence of 17-β-estradiol on NGF and TRPV1 expression in TMJ synovium was determined in vivo and in vitro and analyzed by Western blot and real-time PCR. Complete Freund's adjuvant (CFA) injection into the TMJ was used to induce TMJ arthritis. Capsazepine served as a TRPV1 antagonist. Head withdrawal threshold was examined using a von Frey Anesthesiometer. We observed that estradiol upregulated the expressions of TRPV1 and NGF in a dose-dependent manner. In the primary cultured synoviocytes, TRPV1 was upregulated by lipopolysaccharide (LPS), estradiol, and NGF, while NGF antibodies fully blocked LPS and estradiol-induced upregulation of TRPV1. Activation of TRPV1 in the primary synoviocytes with capsaicin, a TRPV1 agonist, dose-dependently enhanced COX-2 transcription. Moreover, intra-TMJ injection of TRPV1 antagonist, capsazepine, significantly attenuated allodynia of the inflamed TMJ induced by intra-TMJ injection of CFA in female rats. This article presents a possible local mechanism for estradiol that may be involved in TMJ inflammation or pain in the synovial membrane through the pain-related gene TRPV1. This finding could potentially help clinicians understand the sexual dimorphism of TMD pain.

Effects of glucosamine-chondroitin combination on synovial fluid IL-1β, IL-6, TNF-α and PGE2 levels in internal derangements of temporomandibular joint

BACKGROUND

The aim of the present study was to evaluate the effects of glucosamine-chondroitin sulphate combination on internal derangements of temporomandibular joint in clinical and biochemical manners.

MATERIAL AND METHODS

This randomized clinical study included 31 cases reporting joint tenderness, in which disc displacement was detected on MR imaging. In all patients, synovial fluid sampling was performed under local anesthesia. In the study group, the patients were prescribed a combination of 1500 mg glucosamine and 1200 mg chondroitin sulphate, while patients in the control group were only prescribed 50 mg tramadol HCl (twice daily) for pain control. After 8 weeks, synovial fluid sampling was repeated in the same manner. The levels of pain, maximum mouth opening (MMO), synovial fluid IL-1ß, IL-6, TNF-α and PGE2 measured before and after pharmacological intervention were compared.

RESULTS

The reduction in pain levels was significant in both groups. There was no significant difference between two groups in terms of pain reduction. The improvement in MMO was significant in the study group but it was not in the control group. The MMO improvement was significantly higher in the study group compared to the control group. In the study group, significant decrease was observed in PGE2 level, while the decreases in IL-1β, IL-6 and TNF-α levels were not significant. In the control group, no significant decrease was observed in any of the inflammatory cytokines after 8 weeks, moreover IL-1ß and IL-6 levels were increased. Alterations of IL-1ß and IL-6 levels were significant in study group while TNF-α and PGE2 levels were not, compared to control group.

CONCLUSIONS

In conclusion, these results might suggest that glucosamine-chondroitin combination significantly increases the MMO and decreases the synovial fluid IL1β and IL6 levels in internal derangements of TMJ compared to tramadol. The modifications of synovial fluid TNF-α and PGE2 levels do not reach statistical significance. This combination also provides efficient pain relief in similar level with tramadol, a narcotic analgesic.

Celecoxib exerts protective effects on extracellular matrix metabolism of mandibular condylar chondrocytes under excessive mechanical stress

OBJECTIVE

Excessive mechanical stress is considered a major cause of temporomandibular joint osteoarthritis (TMJ-OA). High magnitude cyclic tensile strain (CTS) up-regulates pro-inflammatory cytokines and matrix metalloproteinases (MMPs) in chondrocytes, while selective cyclooxygenase (COX)-2 inhibition has been shown to be beneficial to cytokine-induced cartilage damage. However, the effect of selective COX-2 inhibitors on mechanically stimulated chondrocytes remains unclear. This study evaluated the effect of celecoxib, a selective COX-2 inhibitor, on extracellular matrix (ECM) metabolism of mandibular condylar chondrocytes under CTS.

METHODS

Porcine mandibular chondrocytes were subjected to CTS of 0.5 Hz, 10% elongation with celecoxib for 24 h. The gene expressions of COX-2, MMPs, aggrecanase (ADAMTS), type II collagen and aggrecan were examined by real-time PCR. Also, prostaglandin E2 (PGE2) concentrations were determined using enzyme immunoassay kit. The levels of MMP and transcription factor NF-κB were measured by western blot while MMP activity was determined by casein zymography.

RESULTS

The presence of celecoxib normalized the release of PGE2 and diminished the CTS-induced COX-2, MMP-1, MMP-3, MMP-9 and ADAMTS-5 gene expressions while recovered the downregulated type II collagen and aggrecan gene expressions. Concurrently, celecoxib showed inhibition of NF-κB and suppression of MMP production and activity.

CONCLUSIONS

Celecoxib exerts protective effects on mandibular condylar chondrocytes under CTS stimulation by diminishing degradation and restoring synthesis of ECM.

Intra-articular injections with corticosteroids and sodium hyaluronate for treating temporomandibular joint disorders: a systematic review

INTRODUCTION

In some cases, conservative treatment of internal derangements of the Temporomandibular Joint (TMJ) is considered little responsive. Thus, it is necessary to accomplish treatments that aim at reducing pain and improve function in patients who present arthrogenic temporomandibular disorders.

OBJECTIVE

This study, by means of a systematic review of the literature, aimed to analyze the effectiveness of intra-articular injections with corticosteroids and sodium hyaluronate for treating internal derangements of the TMJ.

METHODS

Carry out a research in the following databases: MEDLINE, Cochrane, EMBASE, Pubmed, Lilacs, and BBO, considering publications issued between 1966 and October 2010, focusing on randomized or quasi-randomized controlled clinical trials, single or double-blind.

RESULTS

After applying the inclusion criteria we collected 9 articles, 7 of which were randomized controlled double-blind clinical trials and 2 randomized controlled single-blind clinical trials.

CONCLUSION

After analyzing the literature, it was found that intra-articular injection with corticosteroids and sodium hyaluronate seems to be an effective method for treating internal derangements of the TMJ. However, further randomized controlled clinical trials, with representative samples and longer follow-up time must be carried out in order to assess the real effectiveness of this technique.

Increased interleukin-1α and prostaglandin E2 expression in the spinal cord at 1 day after painful facet joint injury: evidence of early spinal inflammation

STUDY DESIGN

This study used immunohistochemistry and an enzyme immunoassay to quantify interleukin-1α (IL-1α) and prostaglandin E2 (PGE2) levels in the spinal cord of rats at 1 day after painful cervical facet joint injury.

OBJECTIVE

The objective of this study was to determine to what extent spinal inflammation is initiated early after a painful loading-induced injury of the C6-C7 facet joint in a rat model.

SUMMARY OF BACKGROUND DATA

A common source of neck pain, the cervical facet joint is susceptible to loading-induced injury, which can lead to persistent pain. IL-1α and PGE2 are associated with joint inflammation and pain, both locally in the joint and centrally in the spinal cord. Joint inflammation has been shown to contribute to pain after facet joint injury. Although spinal neuronal hyperactivity is evident within 1 day of painful facet injury, it is unknown if inflammatory mediators, such as IL-1α and PGE2, are also induced early after painful injury.

METHODS

Rats underwent either a painful C6-C7 facet joint distraction or sham procedure. Mechanical sensitivity was assessed, and immunohistochemical and enzyme immunoassay techniques were used to quantify IL-1α and PGE2 expression in the spinal cord at day 1.

RESULTS

Both IL-1α and PGE2 were significantly elevated (P≤ 0.04) at day 1 after painful injury. Moreover, although both spinal IL-1α and PGE2 levels were correlated with the withdrawal threshold in response to mechanical stimulation of the forepaw, this correlation was only significant (P = 0.01) for PGE2.

CONCLUSION

The increased expression of 2 inflammatory markers in the spinal cord at 1 day after painful joint injury suggests that spinal inflammation may contribute to the initiation of pain after cervical facet joint injury. Further studies will help identify functional roles of both spinal IL-1α and PGE2 in loading-induced joint pain.

LEVEL OF EVIDENCE

N/A.

Inflammation is more distinct in temporomandibular joint osteoarthritis compared to the knee joint

PURPOSE

Most of the current understanding of articular cartilage maintenance and degradation is derived from large load-bearing synovial joints, in particular the knee joint. The aim of this study was to identify valuable degradation markers for cartilage degradation in the temporomandibular joint (TMJ) by comparing the relative concentrations of carboxyterminal telopeptides of collagen types I and II (CTX-I and CTX-II), cartilage oligomeric matrix protein (COMP), and prostaglandin E2 (PGE2) in synovial fluid (SF) of TMJ and knee joints with cartilage degradation.

MATERIALS AND METHODS

In this cross-sectional comparative study, participants were recruited from the University Medical Center Groningen, The Netherlands. Patients with TMJ osteoarthritis were compared with patients with knee osteoarthritis. The outcome variables were the relative SF concentrations of CTX-I, CTX-II, COMP, and PGE2. An independent samples Mann-Whitney U test was used to compare the relative concentrations.

RESULTS

Thirty consecutive patients (9 male, 21 female; mean age, 40.1 yr; standard deviation, 15.3 yr) with TMJ osteoarthritis and 31 consecutive patients (20 male, 11 female; mean age, 37.4 yr; standard deviation, 13.7 yr) who were scheduled for arthroscopy of the knee joint participated in this study. Significant differences were found between relative concentrations of COMP (P = .000) and PGE2 (P = .005), and no significant differences were found between relative concentrations of CTX-I (P = .720) and CTX-II (P = .242).

CONCLUSIONS

Relative SF concentrations of COMP and PGE2 showed significant differences between the TMJ and the knee joint, suggesting that there are differences in pathophysiology and that the inflammatory component may be more distinct in the TMJ.

Rationale of arthroscopic surgery of the temporomandibular joint

Arthroscopic surgery has been widely used for treatment of temporomandibular joint (TMJ) internal derangements and diseases for the last 40 years. Although 626 articles have been hit by Pubmed search in terms of "TMJ arthroscopic surgery", this review article is described based on distinguished publishing works and on my experiences with TMJ arthroscopic surgery and related research with an aim to analyse the rationale of arthroscopic surgeries of the temporomandibular joint. With arthrocentesis emerging as an alternative, less invasive, treatment for internal derangement with closed lock, the primary indication of arthroscopic surgery seems to be somewhat limited. However, the value of endoscopic inspection and surgery has its position for both patient and physician with its long-term reliable results.

Alteration of cartilage degeneration and inflammation markers in temporomandibular joint osteoarthritis occurs proportionally

PURPOSE

There is a growing interest in markers for cartilage degradation in synovial joints because of their potential diagnostic and prognostic value. Therefore, the aim of this study was to identify valuable degradation markers for temporomandibular joint (TMJ) osteoarthritis (OA) by comparing the relative concentrations of carboxyterminal telopeptides type I and II (CTX-I and II), cartilage oligomeric matrix protein (COMP), and prostaglandin E2 (PGE2) in the synovial fluid (SF) of TMJs with OA with those of healthy symptom-free TMJs.

MATERIALS AND METHODS

In this cross-sectional case-control study, participants were recruited from the University Medical Center Groningen (Groningen, the Netherlands). Cases were defined as patients with TMJ OA, and control patients had symptom-free TMJs. The outcome variables were the relative concentrations of CTX-I, CTX-II, COMP, and PGE2 in osteoarthritic TMJ SF compared with symptom-free joints. An independent-samples Mann-Whitney U test was used to compare the relative concentrations.

RESULTS

Thirty cases (9 male, 21 female; mean age, 40.1 yr; standard deviation, 15.3 yr) and 10 controls (5 male, 5 female; mean age, 30.3 yr; standard deviation, 10.8 yr) were studied. No significant differences in relative concentrations of CTX-I (P = .548), CTX-II (P = .842), COMP (P = .140), and PGE2 (P = .450) were found between the groups. Unexpected low relative concentrations of CTX-I and high relative concentrations of CTX-II were observed.

CONCLUSIONS

Assumed changes in the SF concentration of CTX-I, CTX-II, COMP, and PGE2 in TMJ OA seem to occur proportionally. Furthermore, the unexpected large contribution of CTX-II suggests that this marker may be useful to quantify cartilage degradation in TMJ OA.

The prostaglandin E2 receptor, EP2, is upregulated in the dorsal root ganglion after painful cervical facet joint injury in the rat

STUDY DESIGN

This study implemented immunohistochemistry to assay prostaglandin E2 (PGE2) receptor EP2 expression in the dorsal root ganglion (DRG) of rats after painful cervical facet joint injury.

OBJECTIVE

To identify if inflammatory cascades are induced in association with cervical facet joint distraction-induced pain by investigating the time course of EP2 expression in the DRG.

SUMMARY OF BACKGROUND DATA

The cervical facet joint is a common source of neck pain, and nonphysiological stretch of the facet capsular ligament can initiate pain from the facet joint via mechanical injury. PGE2 levels are elevated in painful inflamed and arthritic joints, and PGE2 sensitizes joint afferents to mechanical stimulation. Although in vitro studies suggest that the EP2 receptor subtype contributes to painful joint disease, the EP2 response has not been investigated for any association with painful mechanical joint injury.

METHODS

Separate groups of male Holtzman rats underwent either a painful cervical facet joint distraction injury or sham procedure. Bilateral forepaw mechanical allodynia was assessed, and immunohistochemical techniques were used to quantify EP2 expression in the DRG at days 1 and 7.

RESULTS

Facet joint distraction induced mechanical allodynia that was significant (P < 0.024) at all time points. Painful joint injury also significantly elevated total EP2 expression in the DRG at day 1 (P = 0.009), which was maintained at day 7 (P < 0.001). Neuronal expression of EP2 in the DRG was only increased over sham levels at day 1 (P = 0.013).

CONCLUSION

Painful cervical facet joint distraction induces an immediate and sustained increase of EP2 expression in the DRG, implicating peripheral inflammation in the initiation and maintenance of facet joint pain. The transient increase in neuronal EP2 suggests, as in other painful joint conditions, that after joint injury nonneuronal cells may migrate to the DRG, some of which likely express EP2.

Analysis of Criteria for MRI Diagnosis of TMJ Disc Displacement and Arthralgia

Aims. To improve diagnostic criteria for TMJ disc displacement (DD). Methods. The standard protocol for MRI diagnosis of DD, using a 12 o'clock reference position, was compared to an alternative protocol. The alternative protocol involves the functional relationship between the condyle and articular eminence, using a line perpendicular to the posterior slope of the eminence as a reference for disc position. The disc location was examined using both protocols, and disc diagnoses were compared in their relationship with joint pain. Statistical analyses included P value, sensitivity, specificity, odds ratio, and kappa statistic. Results. 58 MRIs were interpreted. 36 subjects reported arthralgia; 22 did not. Both protocols demonstrated significance (standard P = 0.004, alternative P < 0.001) for the ability to predict arthralgia. The odds of arthralgia increased in DD patients diagnosed by standard methods 9.71 times and in DD diagnosed by alternative means 37.15 times. The diagnostic sensitivity decreased 30% using the alternative versus the standard protocol (0.6389 versus 0.9444), while specificity increased 60% (0.9545 versus 0.3636). Conclusions. A stronger relationship occurs between DD and arthralgia when using a function-based protocol. The alternative protocol correctly identifies subjects without arthralgia, who by standard methods would be diagnosed with DD, as having nondisplaced discs, providing a more clinically relevant assessment of TMJ disc displacement.

Interleukin-6 and soluble interleukin-6 receptor suppress osteoclastic differentiation by inducing PGE(2) production in chondrocytes

This study examined how interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6r) influence osteoclastic differentiation through the function of chondrocytes. Chondrocytes were cultured with or without IL-6 and/or sIL-6r in the presence or absence of NS398, a specific inhibitor of cyclooxygenase (COX)-2, for up to 28 days. Chondrocytes were also cultured with or without IL-6 and sIL-6r for 28 days, and the conditioned medium from cells cultured without IL-6 and sIL-6r was used to induce differentiation of RAW264.7 cells into osteoclast precursors. Osteoclastic differentiation was assessed by tartrate-resistant acid phosphatase (TRAP) staining. Expression of osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL), COX-2, and prostaglandin E(2) (PGE(2)) increased in cells exposed to IL-6 and sIL-6r, whereas expression of macrophage colony-stimulating factor (M-CSF) and bone resorption-related enzymes decreased. NS398 blocked the stimulatory/suppressive effects of IL-6 and sIL-6r on the expression of OPG, RANKL, and M-CSF. Fewer TRAP-positive multinucleated cells were detected after treatment with conditioned medium from IL-6- and sIL-6r-treated chondrocytes than after treatment with conditioned medium from untreated chondrocytes. These results suggest that IL-6 and sIL-6r interfere with osteoclast function through the involvement of chondrocytes. Specifically, they appear to suppress the differentiation of osteoclast precursors into osteoclasts by inducing chondrocytic PGE(2) production, which, in turn, increases OPG secretion and decreases M-CSF secretion by chondrocytes.

Preliminary evaluation of histological changes found in a mechanical arthropatic temporomandibular joint (TMJ) exposed to an intra-articular Hyaluronic acid (HA) injection, in a rat model

OBJECTIVE

This study investigates the histological effects of Hyaluronic acid injections in the treatment of induced temporomandibular joint (TMJ) osteoarthritis in rats.

STUDY DESIGN

Twenty-four male Wister rats were subjected to induced mechanical osteoarthritis by manual hypermobility for 10 successive days. Animals were then divided into two groups; group I (control) and group II (experimental). Ten days after the induction of hypermobility, the right TMJ of the experimental animals was injected with a dose of 0.12 mg HA intra-articularly and 0.12 mg saline was injected into the left joint; while animals in the control group were left without any treatment. Two rats from group I were killed at one, two and six weeks; while 6 animals from group II were killed at one, two and four weeks post injection.

RESULTS

The disk of the right joints in the experimental animals was of normal thickness and there was an increase in the thickness of the fibrocartilagenous layer. In the left joint; ulcerative changes in the disk were evident where the fibres were not well oriented and scalloped areas in the temporal bone area were present denoting osteoclastic activity.

CONCLUSIONS

Repeated intra-articular TMJ injection of Hyaluronic acid appears to be a safe and effective way of inhibiting the progression of osteoarthritic changes in the joint through development of articular cartilage and reducing fibrous tissue proliferation.

Povidone-iodine: an anti-oedematous agent?

Polyvinylpyrrolidone-iodine (PVP-I) is a well-known antiseptic, widely used in various preparations and concentrations in all surgical fields. It is also used as an irrigant for open wounds and in some centres for irrigating sockets after tooth extraction. One of the authors (GA) incidentally discovered an anti-oedematous effect of PVP-I after using it in low concentration as an irrigant/coolant during the surgical removal of lower third molars. A prospective randomized clinical trial was subsequently performed on 50 patients (25 control, 25 treatment group) undergoing removal of impacted lower third molars. In the treatment group a 0.5% PVP-I solution at a concentration of 0.5mg/ml (we call it as "Arakeri's iodine solution") resulted in a significant reduction in postoperative swelling compared with the control group (P<0.01). This effect of PVP-I was suspected due to its inhibitory effect on leukotriene B4 and leukocyte extravasation (chemotaxis). Further evaluation of the effects of PVP-I as an irrigant in oral and maxillofacial surgery is needed.

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

OBJECTIVE

The aim of this study was to investigate the effect of intra-articular sodium hyaluronate (SH) injections on the main components of plasminogen activator (PA) system in the synovial fluid of temporomandibular joint (TMJ) osteoarthritis (OA).

STUDY DESIGN

Forty patients diagnosed with TMJ OA and 20 healthy control subjects were included in this study. Synovial fluid was collected in the OA group and the healthy group at baseline. The OA patients were randomly divided into 2 groups (20 patients for each group): One group received 5 injections of SH, and the other received 5 injections of physiologic saline solution in the upper joint space at weekly intervals. Synovial fluid was collected before and after treatment. Urokinase-type PA (uPA), soluble uPA receptor (suPAR) and PA inhibitor 1 (PAI-1) levels in synovial fluid were quantified by enzyme-linked immunosorbent assay.

RESULTS

The OA patients had significantly higher uPA activity and levels of uPA (median 80.01 ng/L), suPAR (median 7.54 ng/L), and PAI-1 (median 54.9 ng/mL) than the healthy control subjects (median 20.47 ng/L uPA, 2.34 ng/L suPAR, and 19.9 ng/mL PAI-1; (P < .05). The uPA activity and levels of uPA, suPAR, and PAI-1 were significantly decreased after SH injections in TMJs of OA patients (P < .05), and there was no difference after saline injection. Visual analog pain score reduction correlated with changes in uPA and uPAR levels as well as uPA activity.

CONCLUSION

The effects of SH on PA system provide new insight into a possible underlying mechanism by which SH alleviates pain of patients with TMJ OA.

Joint disorder: nonreducing disc displacement with mouth opening limitation - report of a case

The internal derangement of the temporomandibular joint (TMJ) represents 8% of all cases of temporomandibular disorders (TMD) posing difficulties to establish an accurate diagnosis and treatment because of its low prevalence. This article presents the case of an 18-year-old Caucasian female patient who came to our Orofacial Pain and TMD Outpatient Service with complaints of intense pain on the right TMJ and limitation of mouth opening (maximum interincisal opening of 29 mm) with deviation to right, which she had been experiencing for the past 3 years. After a detailed clinical interview, a diagnosis hypothesis of nonreducing disc displacement with mouth opening limitation was established. The proposed treatment consisted of intra-joint infiltration with anesthetic in the right TMJ followed by jaw manipulation to recapture the articular disc, which was impeding the complete translation movement of the affected TMJ. After jaw manipulation, a new evaluation was done and showed the re-establishment of jaw dynamics with mouth opening and closing without deviation to the right side, clicking, opening limitation or pain. The patient was followed up at 6 months intervals. Two years after treatment, the patient was reevaluated and her mandibular range of motion without aid increased to 54 mm with no clicking, deviation to right, trismus or pain on the TMJ, indicating success of the treatment approach without recurrence of the pathology.

Prostaglandin E2 and its cognate EP receptors control human adult articular cartilage homeostasis and are linked to the pathophysiology of osteoarthritis

OBJECTIVE

To elucidate the pathophysiologic links between prostaglandin E(2) (PGE(2)) and osteoarthritis (OA) by characterizing the catabolic effects of PGE(2) and its unique receptors in human adult articular chondrocytes.

METHODS

Human adult articular chondrocytes were cultured in monolayer or alginate beads with and without PGE(2) and/or agonists of EP receptors, antagonists of EP receptors, and cytokines. Cell survival, proliferation, and total proteoglycan synthesis and accumulation were measured in alginate beads. Chondrocyte-related gene expression and phosphatidylinositol 3-kinase/Akt signaling were assessed by real-time reverse transcription-polymerase chain reaction and Western blotting, respectively, using a monolayer cell culture model.

RESULTS

Stimulation of human articular chondrocytes with PGE(2) through the EP2 receptor suppressed proteoglycan accumulation and synthesis, suppressed aggrecan gene expression, did not appreciably affect expression of matrix-degrading enzymes, and decreased the type II collagen:type I collagen ratio. EP2 and EP4 receptors were expressed at higher levels in knee cartilage than in ankle cartilage and in a grade-dependent manner. PGE(2) titration combined with interleukin-1 (IL-1) synergistically accelerated expression of pain-associated molecules such as inducible nitric oxide synthase and IL-6. Finally, stimulation with exogenous PGE(2) or an EP2 receptor-specific agonist inhibited activation of Akt that was induced by insulin-like growth factor 1.

CONCLUSION

PGE(2) exerts an antianabolic effect on human adult articular cartilage in vitro, and EP2 and EP4 receptor antagonists may represent effective therapeutic agents for the treatment of OA.

IL-1beta stimulates the expression of prostaglandin receptor EP4 in human chondrocytes by increasing production of prostaglandin E2

Prostaglandin (PG) E(2), which exerts its actions via the PG receptors EP1-4, is produced from arachidonic acid by cyclooxygenase (COX)-1 and COX-2. The aim of this study was to investigate the mechanisms by which interleukin (IL)-1beta induces the expression of PG receptors in cultured human chondrocytes and to explore the role of PGE(2) in this process. The cells were cultured with 0, 10, or 100 U/mL IL-1beta with or without 1 muM celecoxib, a specific inhibitor of COX-2, for up to 28 days. Expression of the genes encoding COX-1, COX-2, and EP1-4 was quantified using real-time PCR, and expression of the corresponding proteins was examined using immunohistochemical staining. PGE(2) production was determined using ELISA. IL-1beta treatment caused a marked dose- and time-dependent increase in the levels of PGE(2), COX-2, and EP4 as compared with the untreated control. It did not affect the expression of COX-1, and it decreased the expression of EP1 and EP2. EP3 expression was not detected in either the absence or the presence of IL-1beta. When celecoxib was also present, IL-1beta failed to stimulate PGE(2) production and EP4 expression, but its stimulatory effect on COX-2 expression and its inhibitory effect on EP1 and EP2 expression were unchanged. IL-1beta increases the production of PGE(2), COX-2, and the PG receptor EP4 in cultured human chondrocytes. The increase in EP4 expression appears to be a result of the increased PGE(2) production.

Modulation of paratrigeminal nociceptive neurons following temporomandibular joint inflammation in rats

To evaluate the involvement of paratrigeminal nucleus (Pa5) nociceptive neurons in temporomandibular joint (TMJ) inflammation-induced pain and its autonomic correlates, we conducted behavioral, single unit recording and Fos immunohistochemical studies in anesthetized rats. Nocifensive behaviors to mechanical, heat or cold stimulation of the lateral face over the TMJ region were significantly enhanced in the TMJ-inflamed rats for 10-14 days after injection of complete Freund's adjuvant (CFA) into the TMJ and gradually decreased at the end of the 14-day observation period. Lowering of the nocifensive threshold in TMJ-inflamed rats lasted longer in vagus nerve-transected rats than vagus nerve-intact rats. A large number of Fos-like immunoreactive (LI) cells were observed in the Pa5, and half of them were retrogradely labeled with Fluorogold (FG) injected into the parabrachial nucleus. Background activity of Pa5 wide dynamic range and nociceptive specific neurons was significantly higher in the TMJ-inflamed rats when compared with controls. Responses to mechanical stimuli were significantly higher in NS neurons in the TMJ-inflamed rats. All thermal responsive Pa5 neurons were exclusively sensitive to cold and the response to cold was significantly higher in the TMJ-inflamed rats compared with control rats. Vagus nerve stimulation significantly decreased responses to mechanical and cold stimuli as well as the background activity in TMJ-treated rats but not in TMJ-untreated rats. The present findings suggest that populations of Pa5 neurons are nociceptive and involved in TMJ inflammation-induced pain as well as in autonomic processes related to TMJ pain.

Neuro-reflexotherapy for the management of myofascial temporomandibular joint pain: a double-blind, placebo-controlled, randomized clinical trial

PURPOSE

To assess the efficacy of neuro-reflexotherapy intervention (NRT) for treating temporomandibular joint dysfunction attributed to myofascial pain. Neuro-reflexotherapy intervention consists of the temporary implantation of epidermal devices in trigger points in the back and ear. It has shown efficacy, effectiveness, and cost-effectiveness in treating subacute and chronic common back pain. No study, however, has explored its efficacy in treating myofascial temporomandibular joint pain (MF/TMJP).

PATIENTS AND METHODS

This was a randomized, double-blind, placebo-controlled trial. Patients with MF/TMJP for more than 3 months in spite of conservative treatment, and with no evidence of major structural damage in the joint, were recruited at the Maxillofacial Department of the Hospital Clínico Universitario, a teaching hospital in Madrid, Spain. Patients were randomly assigned to an intervention group and to a control group. Patients in the treated group underwent 2 NRTs, immediately after baseline assessment and 45 days later. Sham interventions in the control group consisted of placement of the same number of epidermal devices within a 5-cm radius of the target zones. In both groups, conservative treatment during follow-up was allowed and recorded. Patients underwent clinical evaluations on 4 occasions: 5 minutes before intervention, 5 minutes after intervention, and 45 and 90 days later. The preintervention assessment was performed by the physician at the hospital service who included the patient in the study. The 3 follow-up assessments were performed independently by 1 of 2 physicians who had no connection with the research team, and who were blinded to patients' assignments. The primary outcome variable was level of pain severity during jaw movements at the last assessment (90 days), and the key comparison of interest was change in pain over time (pain levels at baseline and at 90 days). Level of pain was measured using a visual analog scale (VAS).

RESULTS

Fifty-one patients with MF/TMJP were recruited into the study. Random assignment allocated 27 patients to the intervention group, and 24 to the control group. Differences in pain severity in favor of the intervention group appeared immediately after the intervention, persisted for 45 days, and increased after the second intervention. Differences at last follow-up were highly clinically and statistically significant (4 to 5 points on the VAS, P = .000), allowing for patients in the intervention group to cease drug treatment (P = .005). There were no differences in the evolution of crepitus or clicking in the joint. There were no clinically relevant side effects associated with the intervention.

CONCLUSIONS

For patients in whom conservative treatment has failed, NRT improves the chronic pain associated with MF/TMJP syndrome.

Evaluation of mouth opening exercise after pumping of the temporomandibular joint in patients with nonreducing disc displacement

PURPOSE

The purpose of this study was to investigate whether an additional mouth opening exercise contributes to better outcome in patients with nonreducing disc displacement who underwent pumping of the temporomandibular joint (TMJ).

PATIENTS AND METHODS

Twenty-three female patients with nonreducing disc displacement of the TMJ underwent pumping of the TMJ and did mouth opening exercise after this treatment (rehabilitation group). Thirty-six female patients with nonreducing disc displacement of the TMJ underwent pumping of the TMJ, but did not do mouth opening exercise (non-rehabilitation group). Patients' signs and symptoms were examined monthly. Clinical evaluation was conducted according to the criteria presented by the 1995 American Association of Oral and Maxillofacial Surgeons. Outcomes were compared between the 2 groups at 12-month follow-up. Chi-square tests were used to assess the difference in good resolution rate between the 2 groups. When significant difference was not found, a non-inferiority test (Delta = 0.1) was used. Level of significance was set on P values less than .05.

RESULTS

In both groups, clinical signs and symptoms improved. There was a good resolution rate of 60.9% in the rehabilitation group and 75% in the non-rehabilitation group. No significant difference was observed between the 2 groups. The non-inferiority test showed that the good resolution rate of the non-rehabilitation group was significantly equivalent or more to that of the rehabilitation group (P < .05).

CONCLUSIONS

Mouth opening exercise did not seem to contribute to better outcomes in patients with nonreducing disc displacement who underwent pumping of the TMJ.

Expression of interleukin 8 in synovial tissues in patients with internal derangement of the temporomandibular joint and its relationship with clinical variables

OBJECTIVES

The objectives of this study were to assay interleukin 8 (IL-8) in synovial tissues of the temporomandibular joint (TMJ) with symptomatic internal derangement, and to assess its relationship with clinical variables.

STUDY DESIGN

Forty-six joints in 44 patients were examined using an immunohistochemical technique. As controls, 8 joints in 7 subjects with habitual dislocation without pain were also examined.

RESULTS

IL-8 was expressed mainly in the blood vessels beneath the lining cells in 37 of the 46 joints (80%) with internal derangement and in 2 of the 8 control joints. The percentage of IL-8-positive cells was significantly higher in the internal derangement group than in the control group (P = .004). The percentage of IL-8-positive cells showed no correlation with joint pain or number of infiltrating cells.

CONCLUSIONS

IL-8 was up-regulated in inflamed synovial tissues in patients with internal derangement. Because IL-8 has no significant correlation with clinical variables, IL-8 may play a secondary role in the pathogenesis of the internal derangement of the TMJ.

Prognostic factors in arthrocentesis of the temporomandibular joint: Comparison of bradykinin, leukotriene B4, prostaglandin E2, and substance P level in synovial fluid between successful and unsuccessful cases

PURPOSE

To compare levels of bradykinin (BK), leukotriene B4 (LTB4), prostaglandin E2 (PGE2), and substance P (SP) between successful and unsuccessful cases of arthrocentesis of temporomandibular joint disorders (TMDs).

PATIENTS AND METHODS

A total of 66 joints in 66 patients with TMDs who underwent arthrocentesis were evaluated in this study. Synovial fluid diluted with saline solution was aspirated from the superior joint compartment before arthrocentesis and their concentrations of BK, LTB4, PGE2, and SP were determined by enzyme-linked immunosorbent assay. The differences in the detection rate and concentration of each mediator between successful cases and unsuccessful cases of arthrocentesis were analyzed statistically.

RESULTS

Arthrocentesis was successful for 77% (51/66) of the joints. The mean detection rate of LTB4 was significantly (P < .05) higher in the unsuccessful cases (47%) than in the successful cases (16%). The mean concentration of BK was significantly (P < .0005) higher in the unsuccessful cases (425 pg/mL) than in the successful cases (144 pg/mL). There was also a statistical correlation between the detection of LTB4 and PGE2 (P < .01).

CONCLUSIONS

Increased levels of BK and LTB4 in the synovial fluid of patients with TMDs may indicate that arthrocentesis is less likely to be a successful treatment.

Induction of osteoclast-like cells derived from the synovial lavage fluids of patients with temporomandibular joint disorders

OBJECTIVE

Although biochemical studies have examined the synovial fluid (SF) of patients with temporomandibular joint (TMJ) disorders (TMDs), the details of the molecular mechanism of bone destruction and remodeling remain unknown. In this study, we induced and characterized osteoclast-like cells from the SF of patients with TMD and investigated the participation of these cells in the pathogenesis of TMD.

METHODS

We collected SF cells from patients with TMD after a pumping procedure, cultured osteoclast-like cells, and examined their characteristics, including osteoclast markers and bone resorption activities. In addition, we obtained fibroblastic cells from the SF of TMD patients by continuous sub-culturing. Using these fibroblastic cells, we examined fibroblast markers using immunocytochemical staining and analyzed the receptor activator of nuclear-factor-kappaB ligand (RANKL) mRNA levels. Detection of soluble form of RANKL (sRANKL) in the SF was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Osteoclast-like cells were induced from the SF cells of patients with TMD by adding recombinant human (rh) macrophage colony stimulating factor (M-CSF) and either 1,25-dihydroxy vitamin D3 [1,25(OH)2D3] or prostaglandin E2 (PGE2). These multinucleated giant cells were positive for tartrate-resistant acid phosphatase (TRAP) and had the ability to absorb bone. The fibroblastic cells from the SF of TMD patients were positive for fibroblast markers and RANKL mRNA was up-regulated. Detection of sRANKL in SF of patient group was significantly higher than control group.

CONCLUSION

The results suggest that the joint-infiltrating SF cells from TMD patients play important roles in the pathogenesis of these disorders, which is characterized by progressive bone destruction or remodeling.