OK-432 (Picibanil) sclerotherapy for recurrent dislocation of the temporomandibular joint in elderly edentulous patients: Case reports

Dislocation of the temporomandibular joint (TMJ) is a thorny problem not only for a patient but also a doctor. Especially for the elderly edentulous patients, it is very hard to treat the condition although there are many surgical and non-surgical procedures. We successfully treated it in two elderly edentulous patients by injection of OK-432 as a sclerosing agent.

Indirect mechanism of histamine-induced nociception in temporomandibular joint of rats

A considerable amount of evidence suggests that temporomandibular joint (TMJ) pain associated with temporomandibular disorder results, at least in part, from an inflammatory episode. Although histamine can cause pain, it is not clear whether this mediator induces nociception in the TMJ. In this study, we investigated the contribution of endogenous histamine to formalin-induced nociception in the TMJ of rats. We also investigated whether the administration of histamine induces nociception in the TMJ and, if so, whether this effect is mediated by an indirect action on primary afferent nociceptors. Local administration of the H1-receptor antagonist pyrilamine prevented formalin-induced nociception in the TMJ in a dose-dependent manner. Local administration of histamine (250 microg) in the TMJ induced nociceptive behavior that was inhibited by co-administration of the lidocaine N-ethyl bromide quaternary salt QX-314 (2%) or the selective H1-receptor antagonist pyrilamine (400 microg). Nociception induced by histamine was also inhibited by pre-treatment with sodium cromoglycate (800 microg) and by co-administration of the 5-HT(3) receptor antagonist tropisetron (400 mug), while pyrilamine (400 mug) did not inhibit nociception induced by 5-hydroxytryptamine (5-HT, 250 microg) in the TMJ. Furthermore, histamine, in a dose that did not induce nociception by itself, strongly enhanced 5-HT-induced nociception. Finally, the administration of a sub-threshold dose of 5-HT (100 microg), but not of histamine (100 microg), elicited nociception in the TMJ previously challenged with the inflammatory agent carrageenan (100 microg). In conclusion, these data suggest that histamine induces TMJ nociception by an indirect mechanism involving endogenous release of 5-HT and activation of 5-HT(3) receptors on sensory afferents. It is proposed that histamine activates the H1 receptor to induce the release of 5-HT which depolarizes the nociceptor by activating 5-HT(3) receptor.

The therapeutic use of botulinum toxin in cervical and maxillofacial conditions: an evidence-based review

INTRODUCTION

The role of botulinum toxin as a therapeutic agent for several conditions is expanding. We sought to determine if botulinum toxin is safe and effective in treating patients with cervical dystonia and maxillofacial conditions. Our purpose was to establish a safety and efficacy profile to determine whether or not this treatment may be used prophylactically in patients undergoing dental implant therapy.

METHODS

We performed a systematic search of the literature to identify randomized clinical trials evaluating patients treated with botulinum toxin as an adjunct to dental implant therapy, maxillofacial conditions including temporomandibular disorders (TMD), and cervical dystonia.

RESULTS

Four randomized controlled trials (RCTs) met our search criteria in the area of cervical dystonia and chronic facial pain. No RCTs were identified evaluating dental implant therapy. Patients with cervical dystonia exhibited significant improvements in baseline functional, pain, and global assessments compared to placebo. Adverse events were mild and transient with numbers needed to harm (NNH) ranging from 12 to 17. Patients with chronic facial pain improved significantly from baseline in terms of pain compared to placebo. Rates of adverse events were less than 1%.

CONCLUSION

Botulinum toxin appears relatively safe and effective in treating cervical dystonia and chronic facial pain associated with masticatory hyperactivity. No literature exists evaluating its use in dental implantology. Randomized clinical trials are warranted to determine its safety and efficacy in dental implantology and other maxillofacial conditions such as bruxism.

Amelioration of pain and histopathologic joint abnormalities in the Col1-IL-1beta(XAT) mouse model of arthritis by intraarticular induction of mu-opioid receptor into the temporomandibular joint

OBJECTIVE

To evaluate opioid receptor function as a basis for novel antinociceptive therapy in arthritis.

METHODS

We induced human mu-opioid receptor (HuMOR) expression in arthritic joints of mice, using the feline immunodeficiency virus (FIV) vector, which is capable of stably transducing dividing, growth-arrested, and terminally differentiated cells. Male and female Col1-IL-1beta(XAT)-transgenic mice developed on a C57BL/6J background and wild-type littermates were studied.

RESULTS

A single injection of FIV(HuMOR) into the temporomandibular joints of Col1-IL-1beta(XAT)-transgenic mice 1 week prior to induction of arthritis prevented the development of orofacial pain and joint dysfunction, and reduced the degree of histopathologic abnormality in the joint. In addition, FIV(HuMOR) prevented the attendant sensitization of trigeminal sensory neurons and activation of astroglia in brainstem trigeminal sensory nuclei. These effects were mediated by the transduction of primary sensory neurons via transport of FIV vectors from peripheral nerve endings to sensory ganglia, as evidenced by HuMOR expression in neuronal cell bodies located in the trigeminal ganglia, as well as in their proximal and distal nerve branches located in the main sensory and subnucleus caudalis of the brainstem and joints, respectively. The presence of MOR ligands predominantly in the descending trigeminal nucleus suggested that the observed antinociception occurred at the subnucleus caudalis. Articular chondrocytes and meniscal tissue were also infected by FIV(HuMOR), which presumably exerted an antiinflammatory effect on cartilage.

CONCLUSION

Our results indicate that prophylactic therapy with MOR overexpression in joints can successfully prevent the development of pain, dysfunction, and histopathologic abnormalities in the joints in arthritis. These findings may provide a basis for the future development of spatiotemporally controlled antinociceptive and antiinflammatory therapy for arthritis.

Effects of COX-2 inhibitor in temporomandibular joint acute inflammation

Since it is recognized that cyclo-oxygenase-2 mediates nociception and the sleep-wake cycle as well, and that acute inflammation of the temporomandibular joint (TMJ) results in sleep disturbances, we hypothesized that cyclo-oxygenase-2 inhibitor would restore the sleep pattern in this inflammatory rat model. First, sleep was monitored after the injection of Freund's adjuvant (FA group) or saline (SHAM group) into the rats' temporomandibular joint. Second, etoricoxib was co-administered in these groups. The Freund's adjuvant group showed a reduction in sleep efficiency, in rapid eye movement (REM), and in non-REM sleep, and an increase in sleep and REM sleep latency when compared with the SHAM group, while etoricoxib substantially increased sleep quality in the Freund's adjuvant group. These parameters returned progressively to those found in the SHAM group. Etoricoxib improved the sleep parameters, suggesting the involvement of the cyclo-oxygenase-2 enzyme in acute inflammation of the TMJ, specifically in REM sleep.

Fibrous myopathy as a complication of repeated intramuscular injections for chronic headache

Two cases of fibrous myopathy associated with repeated, long-term intramuscular injections for treatment of chronic temporomandibular joint pain and chronic headache, respectively, are described. Both patients developed severe, function-limiting contractures in upper and lower extremity muscles used as injection sites. In one of the cases, the contractures were painful. Electrophysiological testing, magnetic resonance imaging and muscle biopsy results were all consistent with myopathy and replacement of skeletal muscle with noncontractile fibrous tissue. These cases are presented to increase awareness of fibrous myopathy and to promote surveillance for this serious potential complication of long-term intramuscular injections in chronic headache and other pain patients.

Randomized effectiveness study of four therapeutic strategies for TMJ closed lock

For individuals with temporomandibular joint (TMJ) disc displacement without reduction with limited mouth opening (closed lock), interventions vary from minimal treatment to surgery. In a single-blind trial, 106 individuals with TMJ closed lock were randomized among medical management, rehabilitation, arthroscopic surgery with post-operative rehabilitation, or arthroplasty with post-operative rehabilitation. Evaluations at baseline, 3, 6, 12, 18, 24, and 60 months used the Craniomandibular Index (CMI) and Symptom Severity Index (SSI) for jaw function and TMJ pain respectively. Using an intention-to-treat analysis, we observed no between-group difference at any follow-up for CMI (p > or = 0.33) or SSI (p > or = 0.08). Both outcomes showed within-group improvement (p < 0.0001) for all groups. The findings of this study suggest that primary treatment for individuals with TMJ closed lock should consist of medical management or rehabilitation. The use of this approach will avoid unnecessary surgical procedures.

Manual physical therapy interventions and exercise for patients with temporomandibular disorders

The purpose of this study was to investigate the outcome of a series of consecutive patients with temporomandibular disorder (TMD) who were treated with manual physical therapy interventions and exercise. Consecutive patients with the clinical presentation of TMD completed several self-report measures and underwent a standardized historical and physical examination. Following the examination, patients received a multimodal treatment approach incorporating manual physical therapy and exercise. All self-report questionnaires were completed at a 2-week follow-up. Paired t-tests were performed between the baseline and 2-week follow-up scores. The mean TMD Disability Index scores were 32.1% (15.4%) at baseline and 18.3% (12.5%) at the 2-week follow-up, representing an improvement of 13.9% (CI: 8.2%, 19.5%) (p < 0.05). Patient Specific Functional Scale (PSFS) scores improved 3.1 points (CI: 2.3, 3.9) (p < 0.05). These results suggest that patients with TMD who are treated with a rehabilitation program including manual physical therapy interventions plus exercise, with or without iontophoresis with dexamethasone, can demonstrate clinically meaningful improvements in disability and overall perceived change in a relatively short period of time.

Botox: the poison that heals

The application of Botulinum toxin has become a useful and significant tool for oral and maxillofacial lesions. The art of using Botulinum toxin, a technical procedure, is influenced by aesthetic judgement and applications that extend beyond its use of reducing wrinkles to improve facial forms and shape. Novel uses for this unique substance will continue to permeate many medical and surgical specialties. Botulinum toxin delivered using more precise techniques may permit improved results without undesired consequences.

A critical review of the use of botulinum toxin in orofacial pain disorders

This article reviews the appropriate use, cautions, and contraindication for botulinum neurotoxin (BoNT) and reviews the peer-reviewed literature that describes its efficacy for treatment of various chronic orofacial pain disorders. The literature has long suggested that BoNT is of value for orofacial hyperactivity and more recently for some orofacial pain disorders; however, the results are not as promising for orofacial pain. The available data from randomized, double-blind, placebo-controlled trials (RBCTs) do not support the use of BoNT as a substantially better therapy than what is being used already. The one exception is that BoNT has reasonable RBCT data to support its use as a migraine prophylaxis therapy. The major caveat is that the use of BoNT in chronic orofacial pain is "off-label".

CT-Guided Percutaneous Steroid Injection for Management of Inflammatory Arthropathy of the Temporomandibular Joint in Children

OBJECTIVE

The purposes of this study were to retrospectively review an injection technique, to develop a grading system for evaluation of imaging findings, and to report preliminary outcome related to percutaneous CT-guided steroid injection into the temporomandibular joints of children with inflammatory arthropathy.

CONCLUSION

CT-guided steroid injection into the temporomandibular joint of children with inflammatory arthropathy results in clinical and imaging improvement in a substantial proportion of children treated.

Peripheral Sympathetic Component of the Temporomandibular Joint Inflammatory Pain in Rats

The aim of this study was to further validate our carrageenan-induced temporomandibular joint (TMJ) inflammatory hyperalgesia model in rats by showing that administration of indomethacin before the initiation of inflammation would diminish the TMJ hyperalgesia. Using this model, we investigated whether norepinephrine and local beta-adrenoceptors contribute to the development of inflammatory TMJ hyperalgesia. Carrageenan-induced TMJ hyperalgesia was assessed by measuring the behavioral nociceptive responses, such as rubbing the orofacial region and flinching the head, induced by the injection of a low dose of 5-hydroxytryptamine into the TMJ sensitized 1 h before by a TMJ injection of carrageenan. Blockade of prostaglandin synthesis by indomethacin prior to initiation of inflammation by carrageenan significantly attenuated the TMJ hyperalgesia. The guanethidine depletion of norepinephrine or the blockade of beta(2)but not the blockade of the beta(1)-adrenoceptor by the selective adrenoceptor antagonists ICI 118.55 and atenolol, respectively, significantly reduced carrageenan-induced TMJ hyperalgesia. In the present study, we further validated our carrageenan-induced TMJ hyperalgesia model to study the mechanisms involved in inflammatory TMJ hyperalgesia and to test the analgesic effect of different types of peripheral analgesics. We also demonstrated that norepinephrine released at the site of injury contributes to the development of the inflammatory TMJ hyperalgesia by the activation of beta(2)-adrenoceptors.

PERSPECTIVE

The findings that local sympathomimetic amines contribute to the inflammatory TMJ hyperalgesia by activating beta(2)-adrenoceptors may be relevant to clinical TMJ inflammatory pain states less sensitive to nonsteroidal anti-inflammatory drugs.

Cervical spine and temporomandibular joint arthritis in a child with Kawasaki disease

Severe neck pain, stiffness, and torticollis in a child with Kawasaki disease commonly represent aseptic meningitis or lymphadenitis. Here we present an unusual case of severe cervical spine and bilateral temporomandibular joint arthritis in a 5-year-old boy with a relapse of Kawasaki disease and coronary artery ectasia. The patient had a favorable response to a second course of intravenous immunoglobulin G and indomethacin therapy, with complete resolution of his symptoms.

Temporomandibular joint arthritis in juvenile idiopathic arthritis: the forgotten joint

PURPOSE OF REVIEW

This review explores the prevalence, clinical and radiographic signs, and treatment of temporomandibular joint arthritis in children with juvenile idiopathic arthritis.

RECENT FINDINGS

Temporomandibular joint arthritis seems to be a more frequent manifestation in patients with juvenile idiopathic arthritis than previously believed, in part due to the paucity of clinical symptoms and poor sensitivity of conventional radiographs used for diagnosis. Antinuclear antibody positivity, early onset of disease, and presence of systemic or polyarticular disease are all risk factors for temporomandibular joint arthritis but may underpredict temporomandibular joint involvement in juvenile idiopathic arthritis. Magnetic resonance imaging enhanced with gadolinium is currently the gold standard in detection of temporomandibular joint arthritis, and treatment with intra-articular corticosteroids has been shown to be effective and safe, with minimal side effects.

SUMMARY

Given the paucity of clinical symptoms in temporomandibular joint arthritis, detection of temporomandibular joint inflammation using contrast-enhanced magnetic resonance imaging is essential for instituting appropriate therapy in a timely fashion. The use of intra-articular corticosteroids holds promise for control of temporomandibular joint inflammation and prevention of associated morbidities.

Short-term therapeutic outcome of intra-articular high molecular weight hyaluronic acid injection for nonreducing disc displacement of the temporomandibular joint

In a patient with temporomandibular disorder who does not respond to conservative treatment, treatment with intra-articular injection of high molecular weight sodium hyaluronate can be suggested. In our study, 27 patients with nonreduced disc displacement were diagnosed clinically and confirmed by magnetic resonance imaging. The age range was from 21 to 63 years old, with a mean of 39.3 years. Two cycles of injection of high molecular weight sodium hyaluronate was performed on alternative weeks. Pain intensity was measured by the visual analog scale. Maximal mouth opening, clicking joint noise, and lateral movement were measured before and after injection for more than 6 months. Reduction of pain intensity and improvement in the maximum mouth opening parameter was statistically significant. In conclusion, this intra-articular injection using high molecular weight sodium hyaluronate looks very positive for patients affected by nonreduced disc displacement and is encouraged to be used as a primary treatment of temporomandibular joint dysfunction.

How may stressful experiences contribute to the development of temporomandibular disorders?

Temporomandibular disorders (TMD) comprise the most common cause of chronic facial pain conditions, and they are often associated with somatic and psychological complaints including fatigue, sleep disturbances, anxiety, and depression. For many health professionals, the subjectivity of pain experience is frequently neglected even when the clinic does not find any plausible biologic explanation for the pain. This strictly biomedical vision of pain cannot be justified scientifically. The purpose of this study is to demonstrate, by original articles from the literature and recent studies conducted in our own laboratory, the biological processes by which psychological stress can be translated into the sensation of pain and contribute to the development of TMD. The role of the hypothalamic-pituitary-adrenal axis, the serotoninergic and opioid systems in the pathogenesis of facial pain is exposed, including possible future therapeutic approaches. It is hoped that knowledge from apparently disparate fields of dentistry, integrated into a multidisciplinary clinical approach to TMD, will improve diagnosis and treatment for this condition through a clinical practice supported by scientific knowledge.

Changes in condylar mobility and radiographic alterations after treatment in patients with non-reducing disc displacementof the temporomandibular joint

OBJECTIVES

The purpose of this study was to examine changes in condylar mobility and morphological changes in the affected condyles after treatment in patients with non-reducing disc displacement of the temporomandibular joint (TMJ).

METHODS

Changes in condylar mobility and morphological changes of the condyle were examined radiographically in 55 patients who were diagnosed as having non-reducing disc displacement of the unilateral TMJ and had received pumping with injection of sodium hyaluronate. In all patients, standardized lateral oblique transcranial radiographs and panoramic jaw tomograms were taken both at initial visit and at 12 months or more follow-up (mean 28.1 months after treatment; range 12-104 months). 42 joints in 21 persons with no current or previous TMJ symptoms served as a control.

RESULTS

Clinical signs and symptoms improved after treatment in the patients. Condylar mobility significantly increased after treatment in patients (P<0.001), although it did not reach levels of the control group. Frequency of radiographic changes of the condyle significantly increased after treatment (P<0.005). In most of the patients, no or only mild changes were observed. Frequency of changes of the condyle in patients at follow-up was significantly greater than that in controls (P<0.001).

CONCLUSIONS

In the patients, condylar mobility increased in the subsequent course after treatment. However, bony changes of the condyle appeared more frequently. Long term-follow-up after treatment on bony changes of the condyle seems to be necessary in patients with non-reducing disc displacement of the TMJ.

[Temporomandibular osteomyelitis secondary to progressive necrotizing otitis externa]

INTRODUCTION

Osteomyelitis of the temporomandibular joint is a rare complication of invasive external otitis, often occurring after inappropriate initial treatment of the causal affection.

OBSERVATION

A 65-year-old diabetic man was treated for invasive otitis externa complicated by destructive osteomyelitis of the ipsilateral temporomandibular joint. The diagnosis was suspected clinically and confirmed by imaging. The course was favorable with medical treatment.

DISCUSSION

Osteomyelitis is an extremely unusual complication of invasive otitis externa. Diffusion of the infection toward the temporomandibular joint can be secondary to an osteitis of the bony canal or spread via congenital dehiscences of the external auditory canal. Pain, limitation of mouth opening and auricular swelling are the main clinical signs. Treatment is essentially medical, based on adapted antibiotic therapy.

A review of the current uses of Botox for dentally-related procedures

Botox is the most widely used abbreviation for botulinum toxin type A (BtA). This drug has received wide coverage in the press and media for its cosmetic advantages, especially in the facial region. The clinician may be aware of the many courses becoming available and aimed at dentists to start using it in the cosmetic context. This paper intends to provide a basic understanding of the many functional uses of the drug in the orofacial region that may be relevant to everyday practice.

CLINICAL RELEVANCE

Awareness of the current medical, as opposed to purely cosmetic, uses of botulinum toxin in the orofacial region is desirable and this paper should inform clinicians and their patients with respect to this increasingly popular drug.

Conservative treatment of temporomandibular joint osteoarthrosis: intra-articular injection of sodium hyaluronate

Promising short-term results in the treatment of temporomandibular joint osteoarthrosis with intra-articular injections of sodium hyaluronate (SH) have been reported in preliminary studies. The present prospective study compared long-term outcomes of temporomandibular joint SH injections with those of a conventional non-surgical treatment (bite-plane). Data from three groups of 20 patients with degenerative temporomandibular joint disease were considered. Group A underwent one cycle of five injections of 1 mL SH. Group B underwent a bite-plane treatment for at least 6 months. We considered a control group of 20 patients who refused any treatments. The description of the outcomes was based on objective and subjective parameters after a 6-month follow-up. Sodium hyaluronate and bite-plane treatments significantly improved patients conditions in all considered parameters. No significant differences in outcomes were confirmed by the statistical analysis. The tolerability of SH treatment resulted to be significantly higher. The analysis of results of serial controls in the SH treated group disclosed a significant worsening in pain at rest by comparing 1 and 6 months follow-up. Sodium hyaluronate infiltration resulted a valid non-surgical treatment for temporomandibular joint degenerative disease. Five well-tolerated intra-articular SH injections achieved equivalent results to those of a 6 months bite-plane treatment. We did not diagnose any complications of SH intra-articular injections. Longer time follow-up is necessary to determine the stability of SH properties.

Prolotherapy (proliferation therapy) in the treatment of TMD

Proliferation therapy, or "prolotherapy," is also known as regenerative injection therapy (RIT). Since the 1930s, the technique has been used to stabilize injured joints and to relieve joint pain. This article reviews the history and scientific literature regarding prolotherapy and describes the application of the technique to treat injured or unstable temporomandibular joints (TMJ). Alternative medicaments and the likely mechanisms of action are discussed. A brief preliminary summary of a retrospective clinical study of the efficacy of prolotherapy is included. The study shows that prolotherapy can be an effective therapeutic modality that reduces TMJ pain and joint noise in a majority of patients who have reached a plateau with use of an intraoral appliance, physical therapy, and home care.

Chronic orofacial pain. Understanding patients from two perspectives: the clinical view and the patient's experience

The aim of this thesis was to study chronic orofacial pain patients from two perspectives--the clinical view and the experience of the patient--in order to improve the understanding of the patients and their condition. All patients had been referred to the Faculty of Odontology, Malmö University, Malmö, Sweden owing to chronic orofacial pain. The clinical perspective was investigated in a retrospective study of 109 consecutive chronic orofacial pain patients (85 females, 24 males) who had been examined by a pain group. Diagnosis, pain status, medication, and education were the parameters studied and pain-related sex differences were calculated. In addition, the patients were mailed a questionnaire after 4-9 years to follow up their pain status and to identify predictors of pain persistence. The patient perspective was investigated by interviewing 14 strategically selected patients (11 female, 3 male) about their lived experience of non-specific chronic orofacial pain. The interviews were of 1-1.5-hour duration and were conducted twice with each patient. The findings from the clinical studies and the interview studies are listed below. The experiences of the interviewed patients revealed additional aspects of several of the findings made in the clinical studies. The majority of the patients were female. Mainly similarities between the sexes were found regarding pain status and the other parameters studied. The patients had a lower level of education than Swedish inhabitants of the same ages. The majority of the patients in the clinical studies reported seeking care repeatedly owing to orofacial pain. The patients in the interview studies experienced distrust and rejection at the consultations for the orofacial pain. They also experienced the pain as elusive and difficult to communicate. Most of the patients in the clinical studies had persistent pain of some intensity at the follow-up 4-9 years later. The interviewed patients expressed a great need to be taken care of and often seemed to have a limited ability to cope with the pain. Among the patients studied clinically, a reported consumption of pharmacological agents with a central effect (opioids, muscle relaxants, antidepressants, neuroleptics, hypnotics, or sedatives) was a predictor of pain persisting at the follow-up. The interviewed patients expressed feelings of hopelessness and a lack of faith in the future. To study patients with chronic orofacial pain from a clinical viewpoint and from a patient perspective led to a deeper understanding of chronic orofacial pain as a complex condition that has an impact on every aspect of the patient's life. The patients often seek dental care because of the pain. It seems to be important in dentistry to develop constructive strategies for caring for these patients--especially when the dental disease condition has already been adequately diagnosed and treated, but the patients still experience pain.

Treatment of severe temporomandibular joint clicking with botulinum toxin in the lateral pterygoid muscle in two cases of anterior disc displacement

A novel treatment procedure is introduced for severe clicking of the temporomandibular joint (TMJ) associated with anterior disc displacement (ADD), using injections with botulinum toxin (BTX-A) in the lateral pterygoid muscle (LP). It has been suggested that ADD may be caused, precipitated, or maintained by LP activity, but the role of the LP in the dynamics of the TMJ clicking is uncertain. The case report includes 2 women, followed with clinical examinations, TMJ imaging, and electromyography (EMG), in whom local anesthetics in the LP could abolish the clicking for several days. BTX-A block of the LP (30 U Botox, given twice under EMG guidance with 6-month interval) temporarily reduced the action of the muscle, but the clicking was permanently eliminated and did not return during the observation period of 1 year, and a small but distinctive positional improvement in the disc-condyle relationship was obtained. However, the precise mechanisms behind the favourable treatment outcome are unclear.

Reduction of temporomandibular joint pain after treatment with a combination of methotrexate and infliximab is associated with changes in synovial fluid and plasma cytokines in rheumatoid arthritis

The aims were to investigate the effect of intravenous infusions of the tumor necrosis factor-alpha (TNF-alpha) antibody infliximab on symptoms and signs of temporomandibular joint (TMJ) involvement in relation to effects on synovial fluid and plasma proinflammatory TNF-alpha, interleukin-1beta (IL-1beta) and interleukin-6 as well as antiinflam matory soluble TNF receptor II (TNF-sRII), interleukin-1 receptor antagonist (IL-1ra), soluble IL-1 receptor II (IL-1sRII) and interleukin-10 (IL-10) in patients with active rheumatoid arthritis (RA). Nineteen patients with TMJ involvement taking methotrexate were included in the study. TMJ and general joint pain intensity as well as pain on mandibular movements, tenderness to digital palpation, pressure pain threshold and maximum mouth-opening capacity were assessed in a clinical examination. The effect of infliximab was assessed after 2 and 14 or 22 weeks. TMJ synovial fluid and venous blood were collected for cytokine analysis at all occasions while determination of erythrocyte sedimentation rate and C-reactive protein were performed at baseline and at long-term follow-up only. Reduction of TMJ pain was associated with raised levels of synovial fluid TNF-sRII and IL-1sRII as well as raised plasma levels of IL-1ra and IL-10. Decreased erythrocyte sedimentation rate was associated with decreased tenderness to digital palpation. Reduced general joint pain intensity was associated with reduced plasma levels of IL-6 and C-reactive protein. In conclusion, systemic treatment with a combination of infliximab and methotrexate reduces TMJ pain in RA in association with an increase in anti-inflammatory cytokines and receptors in synovial fluid and plasma.

The long-term effect of anti TNF-α treatment on temporomandibular joints, oral mucosa, and salivary flow in patients with active rheumatoid arthritis: A pilot study

OBJECTIVE

The objective of this study was to evaluate the long-term effects of anti-TNF-alpha treatment on temporomandibular joints (TMJs), oral mucosa, and salivary flow in RA.

STUDY DESIGN

Seventeen patients received infusions of TNF-alpha blocking agents after 0, 2, and 6 weeks, and then every 8 weeks until week 54 (follow-up). Clinical dysfunction index (Di) for the TMJ system, salivary flow, disease activity score (DAS28), and other medical assessments were calculated at weeks 0 and 54.

RESULTS

Median Di was 5.0 (range 0-21) at baseline and 1.0 (range 0-6) (P = .001) at follow-up. Mean salivary flow was 3.2 mL/15 minutes at baseline and 4.6 at follow-up (P = .055). Two (11.7%) of the patients developed oral candidiasis during the period of treatment. The median DAS28 was 6.2 (range, 4.7-7.7) at baseline and 4.1 (range, 1.6-6.8) at follow-up (P = .001).

CONCLUSION

We conclude that anti-TNF-alpha blocking treatments have beneficial effects on oral as well as general manifestations of RA.

Effect of persistent monoarthritis of the temporomandibular joint region on acute mustard oil-induced excitation of trigeminal subnucleus caudalis neurons in male and female rats

The effect of persistent inflammation of the temporomandibular (TMJ) region on Fos-like immunoreactivity (Fos-LI) evoked by acute noxious stimulation of the same or opposite TMJ was assessed in male and cycling female rats. Two weeks after inflammation of the TMJ by complete Freund's adjuvant (CFA, 25 microg) the selective small fiber excitant, mustard oil (MO, 20%), was injected into the arthritic or opposite TMJ under barbiturate anesthesia. MO stimulation of the arthritic TMJ increased Fos-LI ipsilateral, but not contralateral, to MO compared to naïve subjects in superficial laminae at the trigeminal subnucleus caudalis/upper cervical cord (Vc/C2) junction independent of sex hormone status. Unexpectedly, MO stimulation of the opposite TMJ in arthritic rats also produced a greater Fos-LI response ipsilateral to MO than naïve animals. Fos-LI produced in the dorsal paratrigeminal region (dPa5) and Vc/C2 junction after MO stimulation of the normal TMJ was significantly greater in proestrous than diestrous females or male monoarthritic rats. In contrast to naïve animals, Fos-LI was produced in deep laminae at the Vc/C2 junction ipsilateral to MO in CFA-treated animals independent of the site of prior CFA inflammation or sex hormone status. These results indicated that persistent monoarthritis of the TMJ region enhanced the excitability of trigeminal brainstem neurons to subsequent TMJ injury that occurred bilaterally in multiple regions of the lower trigeminal brainstem complex and depended on sex hormone status.

Specificity of meal pattern analysis as an animal model of determining temporomandibular joint inflammation/pain

Analyzing feeding behavior, and in particular meal duration, can be used as a biological marker for temporomandibular joint (TMJ) inflammation/pain. The present study determined the specificity of meal duration as a measure of TMJ inflammation/pain in a rodent model. The model was also used to test the efficacy of dexamethasone (DEX) as a treatment for TMJ inflammation/pain that was induced by TMJ injection of complete Freund's adjuvant (CFA). In the first study, anesthetized male Sprague-Dawley rats housed in computerized feeding modules received bilateral intra-articular knee injections of CFA or saline. The next day, CFA-injected rats had significant knee swelling and impaired mobility. Food intake in the CFA-injected group was reduced over the next two days and this was due to reduced meal number with no change in meal size. Notably, meal duration was normal in both the CFA and saline knee-injected groups. In the second study, male rats were assigned to one of four groups: Group 1, no CFA and no DEX treatment; Group 2, no CFA and treatment with DEX (0.4 mg/kg i.m. once daily); Group 3, bilateral TMJ CFA injection and no DEX treatment; and Group 4, bilateral TMJ CFA injection and treatment with DEX. CFA significantly increased TMJ swelling and stress-induced chromodacryorrhea in Group 3, but treatment with DEX attenuated these effects in Group 4. Compared to the controls, meal duration was significantly lengthened 24 and 48 h post-CFA injection in Group 3, whereas DEX treatment attenuated TMJ swelling, chromodacryorrhea and normalized meal duration. The data demonstrate that meal pattern analysis, and in particular meal duration, can be used as a non-invasive specific measure of TMJ inflammation/pain and can be used as a marker of DEX treatment efficacy.

Evaluation of the anti-inflammatory effect of erythromycin on aseptic inflammation of temporomandibular joint in rabbit: a scintigraphic and histopathologic study

This article investigates the anti-inflammatory effects of erythromycin (EM) on aseptic inflammation of temporomandibular joint (TMJ) space using by Tc-99 m HIG scintigraphy and histopathology. In this experimental study, 33 adult male New Zealand White rabbits were divided into three groups. The animals in the first group were treated with EM 25 mg kg(-1); the animals in the second group were treated with methylprednisolone (MP) 2 mg kg(-1) and the animals in the third group were given saline solution (control group). Each drug was given by intraperitoneal injection twice a day for 7 days. Two hours after the last injection, carrageenan was injected into right TMJ of rabbits for aseptic inflammation. After carrageenan injection, each rabbit was given an intravenous injection of 111 Mbq (3 mCi) Tc-99 m human HIG, and scanning was performed 4 h later. Later, all animals were killed and TMJ and periarticular tissues were resected. Histopathologically, the distance between synovial surface epithelium (SSE) and muscle layer (ML) in each section was measured by using SAMBA 200 Cell image processor with software. Scintigraphically, when lesion activity/adjacent region activity (L/N) was evaluated there was a significant difference between the control group and the other two groups (P < 0.05 for EM and MP). However, no significant difference was found between the EM and MP groups. Histopathologically, the mean distance between SSE and ML in the sections was found longer in the control group (78.6 +/- 10.7 microm) than in the EM (44.38 +/- 18.26 microm) and MP (44.05. +/- 18.25 microm) groups. We think that administration of EM, which is a well-known macrolid antibiotic, might be very effective in the treatment of aseptic inflammation of TMJ space. Because corticosteroid administration has many side effects, EM may be a preferable drug in the treatment of inflammation of TMJ.

A novel method for subarachnoid drug delivery in the medullary region of rats

This study describes a novel method for direct subarachnoid drug delivery to the medullary dorsal horn region of rats, without introducing a catheter. The reliability of the method was demonstrated by a pharmacological validation; that is, morphine administration to the medullary region blocked the nociceptive response to formalin injected in the temporomandibular joint (TMJ) region, an effect that was prevented by co-administration of naloxone. The method proposed offers many advantages over the existing methods for medullary drug delivery with catheter implantation. It is easy to be employed, it does not induce any sign of motor impairment, and it does not require the neck surgery performed to implant a catheter in the medullary dorsal horn region. Therefore, it is a useful method for subarachnoid drug delivery in behavioral trigeminal pain studies, particularly when nociceptive behavioral measures that require normal neck muscle activity to occur, such as head withdraw or head flinch, are evaluated.

[Histopathological study of the effects of intra-articular injection of triamcinolone acetonide on temporomandibular joint osteoarthrosis in goats]

PURPOSE

The aim of this study was to investigate the histopathological changes of human temporomandibular joint osteoarthrosis following intra-articular injection of triamcinolone acetonide, and compare the results to these of control group.

METHODS

The upper compartments of both joints of 10 goats were injected with 0.8 ml collagenase I to induce osteoarthrosis. The 10 goats were then equally divided into control group and experimental group. The first and second treatment were carried out 30 and 60 days after injection of collagenase I, respectively. The animals were sacrificed 90 days after the first treatment. The specimens of the animal TMJ were harvested, histologically examined under light microscopy and scanning electron microscopy, and scored in a subjective manner following the criteria which was a modification of the method of Mankin et al and Yoshimi et al. GLM model in SAS software package was adopted to compare the differences between the control group and experimental group.

RESULTS

Under light microscopy and scanning electron microscopy, the condyle, meniscus and glenoid fossa of the control group demonstrated distinct osteoarthrosis; the histopathologic changes in the experimental group was more serious than the control group, and the differences of the histologic scores were significant between the two groups (P<0.01).

CONCLUSION

Intra-articular injection of triamcinolone acetonide as a lytic agent will worsen for articular cartilage reparation.

Tempromandibular joint (TMJ) response to intra-articular dexamethasone injection following mechanical arthropathy: a histological study in rats

The purpose of this study was to evaluate as well as to compare the effect of intra-articular versus intra-peritoneal injection of dexamethasone on synovitis induced by trauma to the rat's TMJ. Twenty-seven male Wister rats were included in the present study. Induced forced condylar hypermobility achieved through opening the rat's mouth manually 10 times for 10 consecutive days. Rats were randomized into three groups (3 rats in the control group, and 24 rats in both experimental groups). Group I (control group): Rats of this group were left without any treatment after induction of synovitis. Group II: Rats were injected with a single dose of 1.2 mg/kg dexamethasone intra-articularly (after 10 days). Group III: Rats were injected with a single intra-peritoneal injection of 1.2 mg/kg dexamethasone (after 10 days). Control rats were sacrificed at 6 weeks, while rats in Groups II and III were sacrificed at 1 and 6 weeks after drug injection, then joints were dissected and processed for histological study. The condylar head of the rats injected with intra-articular dexamethasone showed resorption with active osteoclastic activity, although the drug was given only once. This might be an alarming sign of the severe adverse effect(s) of the local injection of dexamethasone.

Pharmacologic treatment of the dysfunctional patient

It is common knowledge that therapeutical approach of temporomandibular disorders (TMD) is multidisciplinary and directed to remove the cause of disorder, to eliminate symptomatology and to make an improvement to patient's life. Most of the subjects observed have pain, often caused by muscular component (90-95%) and rarely by the intercapsule. Generally, it deals with chronic-ache, bound by a layer of stress and by considerable emotionalism. A correct diagnosis is the indispensable requirement for the drugs prescription, not only, but remarkable is: to attach importance to the knowledge of workings action, the side effects and active principals contraindications took into account. This article will be a question of medicines which are the basis of medical therapy for temporal-jaw excess with: analgesic, antinflammatory, short-relaxing and tranquillizer, tricyclical antidepressant and local anesthetic. As regards to TMD, notice that pharmacological therapy must not be over protracted for too much time, especially for use of benzodiazepine and tricyclic antidepressants, dosage demanded are decisively less if we compare, usually main therapeutical indications. The pharmacological therapy can be an agent for competent method for symptomatology treatment of temporal-jaw disorder but, patient must be acquainted about a fact, trouble often could not disappear only with a drug. To conclude, we can assert that the right use of medicines, in addition with physiotherapeutical therapy and an occlusal splint, represent the most efficient means to deal with the majority of temporal-jaw diseases.

Botulinum Toxin for the Treatment of Temporomandibular Joint Disk Disfigurement: Clinical Experience

Type A botulinum toxin was used for the treatment of symptoms of 26 patients (40 joints) with temporomandibular joint disk disfigurement. In all patients, 0.5 ml (12.5 U) was injected into the lateral pterygoid muscle. The temporalis, medial pterygoid, and masseter muscles were injected if severe tenderness was noted. The data were compared using the Wilcoxon signed rank test and the McNemar test. With the exception of clicking of the right joint, all mean outcome measures showed a significant difference between the preinjection and postinjection assessments. There was a significant difference between the preinjection and postinjection pain scores of the right joint (P=0.0019) and the left joint (P=0.000). Postinjection values of the mouth opening (P=0.002), subjective functional dysfunction (P=0.065), and clicking of the left joint (P=0.001) also showed a statistically significant difference from the preinjection values. In addition, the severity and frequency of headache were reduced after botulinum toxin-A injection into the lateral pterygoid muscle.

[Influence of intra-articular injections of sodium hyaluronate on clinical features and synovial fluid nitric oxide levels of temporomandibular osteoarthritis]

OBJECTIVE

This study was designed to assess the effect of intra-articular injection of sodium hyaluronate (SH) on clinical findings of temporomandibular osteoarthritis (OA) and on synovial fluid (SF) levels of nitric oxide (NO).

METHODS

Twenty seven patients (7 men, 20 women, mean (SD) age 53.9 (11.8) years) with OA of the temporomandibular joint were randomly allocated to receive an injection of either SH (2 ml, Hyalgan, Fidia SpA, Abano T., P.M. 500-700.000, 20 mg/2 ml; once a week for 5 weeks) or a Ringer's lactate solution (once a week for 3 weeks). Clinical evaluation was done before each procedure, and at 1 week, 1, 3 and 6 months post-injection. Intensity of temporomandibular joint pain, jaw function, maximal mouth opening and lateral jaw movements were recorded at each visit. NO was measured on SF collected by rinsing the joint with saline 1 ml before the treatment.

RESULTS

Injection of SH caused significant improvement in the main clinical symptoms until the last follow-up which was carried out 6 months after last injection. Among patients who received SH injection, those who reached a good outcome showed the lowest basal levels of NO.

CONCLUSIONS

The results of this study showed that intra-articular injections of SH lead to a lasting improvement in the clinical symptoms of temporomandibular OA. Furthermore, our findings suggest that low NO levels in SF are related to a better outcome of temporomandibular OA among patients treated with SH intra-articular injection.

Relationship between effectiveness of arthrocentesis under sufficient pressure and conditions of the temporomandibular joint

PURPOSE

The purpose of this study is to investigate the conditions of the temporomandibular joint (TMJ) relative to the effectiveness of arthrocentesis under sufficient hydraulic pressure in patients with chronic closed lock.

PATIENTS AND METHODS

We performed arthroscopic examination and arthrocentesis as an initial treatment in 65 closed lock cases (65 joints). Changes in maximum mouth opening and joint pain were examined to determine the effectiveness of the treatment. With respect to the conditions of the TMJ before treatment, we examined the range of maximum mouth opening, joint pain at mouth opening, degrees of disc deformity and bone change evident with magnetic resonance imaging, and the degrees of synovitis, cartilage changes, and adhesion in the upper joint space evident from arthroscopic findings. These factors were statistically analyzed by using multiple regression analysis.

RESULTS

Two months after treatment the maximum mouth opening of the patients increased by an average of 9.8 mm (range, 0 to 28 mm). Joint pain at opening mouth improved an average of 64.2% (range, 0 to 100%). A significant inverse correlation was found between the extent of improvement in maximum mouth opening after treatment and the initial maximum mouth opening before treatment. There was no significant correlation between improvement of joint pain and conditions of the TMJ.

CONCLUSION

Pathologic conditions of the TMJ did not have an influence on the efficacy of arthrocentesis under sufficient pressure. This result suggests that this procedure has wider application than arthrocentesis under low pressure.

Differential modulation of TMJ neurons in superficial laminae of trigeminal subnucleus caudalis/upper cervical cord junction region of male and cycling female rats by morphine

Sex differences in the cellular responses to morphine were examined in an animal model of temporomandibular joint (TMJ) pain. TMJ-responsive neurons were recorded in the superficial laminae at the trigeminal subnucleus caudalis/upper cervical cord (Vc/C(2)) junction region, the initial site of synaptic integration for TMJ afferents, in male and cycling female rats under barbiturate anesthesia. Unit activity was evoked by local injection of bradykinin into the TMJ capsule at 30 min intervals and the effects of morphine sulfate (0.03-3 mg/kg, i.v.) were assessed by a cumulative dose regimen. Morphine caused a dose-related inhibition of bradykinin-evoked unit activity in males and diestrous females in a naloxone-reversible manner, while evoked unit activity in proestrous females was not reduced. The apparent sex hormone-related aspect of morphine analgesia was selective for evoked unit activity, since the spontaneous activity of TMJ units was reduced similarly in all groups, while the convergent cutaneous receptive field area of TMJ units did not change in any group. These results were consistent with the hypothesis that sex hormone status interacts with pain control systems to modify neural activity at the level of the Vc/C(2) junction region relevant for TMD pain.

Utility of corticosteroid injection for temporomandibular arthritis in children with juvenile idiopathic arthritis

OBJECTIVE

To assess the effects of computed tomography (CT)-guided injection of corticosteroid into the temporomandibular joint (TMJ) in children with juvenile idiopathic arthritis (JIA) and clinical and magnetic resonance imaging (MRI) evidence of TMJ inflammation.

METHODS

Twenty-three children ages 4-16 years with JIA and MRI evidence of TMJ inflammation received CT-guided TMJ injections of corticosteroid (triamcinolone acetonide [n = 16] or triamcinolone hexacetonide [n = 7]). Jaw pain or dysfunction and maximal incisal opening (MIO) distance were assessed before and after injection. Fourteen patients had followup MRI studies of the TMJ 6-12 months after injection.

RESULTS

Of the 13 patients with symptoms of jaw pain prior to corticosteroid treatment, 10 (77%) had complete resolution of pain (P < 0.05). Prior to corticosteroid injection, MIO in all 23 patients was below age-matched normal values. After injection, the MIO was improved by at least 0.5 cm in 10 patients (43%) (P = 0.0017). Patients under 6 years of age at the time of injection showed the best response, with a postinjection MIO similar to that in age-matched controls (P = 0.2267). There was involvement of 23 TMJs in the 14 patients who had followup MRI studies; resolution of effusions was observed in 11 (48%) of the TMJs. Other than short-term facial swelling in 2 patients, there were no side effects.

CONCLUSION

The majority of children with symptomatic TMJ arthritis improved after intraarticular corticosteroid injection. Approximately half the patients experienced significant improvement in MIO and TMJ effusion. These data suggest that corticosteroid injection may be a useful procedure for the prevention and treatment of morbidities associated with TMJ arthritis in JIA.

The effect of experimental cartilage damage and impairment and restoration of synovial lubrication on friction in the temporomandibular joint

AIMS

To evaluate how the frictional coefficient of the porcine temporomandibular joint (TMJ) is affected by an impairment of the synovial lubrication produced by an experimental abrasion of the articular cartilage and the application of hyaluronic acid (HA) with different molecular weights to the abraded cartilage surfaces.

METHODS

Erosion of the articular cartilage was produced by scouring it with sandpaper. Impairment and restoration of synovial lubrication were modeled by washing the joint space with phosphate-buffered saline (PBS) and by the application of HA with different molecular weights. After measuring the frictional coefficients in the intact TMJs (n = 10), the effects of washing with PBS, sandpaper scouring, and the application of HA were subsequently examined.

RESULTS

The mean frictional coefficient in the intact joint was 0.0154 (SD 0.0043). After PBS washing and sandpaper scouring, it increased significantly to 0.0235 (SD 0.0052) and 0.0520 (SD 0.0088), respectively. Subsequent application of HA resulted in a significant decrease (43% to 56%) of the frictional coefficient. Observations by scanning electron microscopy showed that after sandpaper scouring, the superficial cartilage layer was disrupted and inner layer was exposed, creating an irregular surface.

CONCLUSION

Joint friction may increase by approximately 350% following an experimental scouring of the cartilage surface and impairment of synovial lubrication. Lubrication by means of HA decreased joint friction by approximately 50%.

Blockade of peripheral 5HT3 receptor attenuates the formalin-induced nocifensive behavior in persistent temporomandibular joint inflammation of rat

The role of peripheral 5HT3 receptors in the orofacial nocifensive behavior induced by the injection of formalin into masseter muscle was evaluated. The behavioral activities evoked by the formalin injection exhibited a biphasic response in the rats with or without temporomandibular joint (TMJ) inflammation (CFA group or non-CFA group). The orofacial nocifensive behavioral activity was enhanced after TMJ inflammation. Systemic administration of tropisetron, 5HT3 receptor antagonist, reduced the nocifensive behavioral activities in the late phase of orofacial formalin test in CFA group, but not in non-CFA group. Local administration of tropisetron into the masseter muscle in CFA group, but not in non-CFA group also attenuated the behavioral activities in the late phase. Unexpectedly, low dose of local tropisetron reduced the nocifensive behavioral activities in the early phase of orofacial formalin test in CFA group. These data suggest that induction of TMJ inflammation causes the elevation of the orofacial nocifensive behavioral activities evoked by formalin injection into masseter muscle, and that peripheral 5HT3 receptors may play a critical role in nociception and the transmission of orofacial pain.

Temporomandibular disorders: standard treatment options

Proper diagnosis is essential in all phases of health care, and dentistry certainly is no exception. Without a proper diagnosis, effective treatment may never be rendered and the patient's suffering and costs will continue to escalate. Dentists who treat patients who have temporomandibular disorders (TMDs) and orofacial pain also must strive to stay abreast of the latest treatment options. This article summarizes the current recommended treatment options for TMDs. Because it would be virtually impossible to cover every type of treatment available, only standard recognized types of treatment will be presented.

Use of Theraflex-TMJ topical cream for the treatment of temporomandibular joint and muscle pain

This randomized, double-blind study was designed to evaluate the effectiveness of the topical cream Theraflex-TMJ (NaBob/Rx, San Mateo, CA) in patients with masseter muscle pain and temporomandibular joint (TMJ) pain. Fifty-two subjects (5 males and 47 females) were instructed to apply a cream over the afflicted masseter muscle(s) or over the jaw joint(s) twice daily for two weeks. Theraflex-TMJ cream was used by the experimental group, while a placebo cream was used by the control group. The means of pain ratings were calculated prior to the application of the cream (baseline), after ten days of tx (period 1), and 15 days of tx (period 2) days of treatment and five days after stopping the treatment (follow-up). There was a significant decrease in reported pain levels from baseline in the experimental group for period 1 (p < 0.01), period 2 (p < 0.001), and follow-up (p < 0.01). For the control group, no significant differences were found between the different time periods (p > 0.05). There was evidence of minor side effects such as skin irritation and/or burning on the site of the application in two subjects in the experimental as well as two subjects in the control groups. The data strongly suggest that Theraflex-TMJ topical cream is safe and effective for reducing pain in the masseter muscle and the temporomandibular joint.

[An outcome analysis of two methods of intra-capsular injection of sodium hyaluronate for temporomandibular disorders]

OBJECTIVE

To analyze the treatment outcome of the two methods of intra-capsular injection of temporomandibular joints, the upper capsule alone and both the upper and lower capsules, for different subtypes of temporomandibular disorders.

METHODS

A retrospective cohort study was designed, based on the outpatients and the data which were obtained from West China Stomatological Hospital, Sichuan University. SPSS10.0 software was used to analyze the data, which were collected before the operation and one week after the operation.

RESULTS

294 patients were followed up. The group of double capsules injection gained better prospect, not only on the mouth-opening but also the pain-cured, especially in two subgroups such as the anterior dislocation of disc without reduction and the osteoarthritis of TMJ.

CONCLUSION

It seems that the double capsules injection of sodium hyaluronate for TMD can gain better outcome than the upper capsule injection, but a clinical randomized controlled test and a long-term follow-up study of the two methods are needed to verify this finding.

Analgesic effect of elastoviscous hyaluronan solutions and the treatment of arthritic pain

Elastoviscous hyaluronan solutions have an analgesic effect when injected intra-articularly in animal and human joints. This was first discovered using animal behavioral models and later confirmed in neurophysiological studies in cat and rat joints. These studies on both normal and experimentally produced arthritis in joints confirmed that only elastoviscous solutions of hyaluronan or certain of its derivatives (hylans) have a desensitizing effect on nociceptive sensory receptors. Recently, this desensitizing effect of elastoviscous hyaluronan solutions was also demonstrated on intact or on isolated patches of oocyte cell membranes. Viscosupplementation, the exchange of pathological synovial fluid in arthritic joints with pure elastoviscous solutions of hyaluronan or hylans, is a widely accepted therapeutic modality used to provide long-lasting analgesia in human knee joints. The clinical studies performed on human and animal temporomandibular joints since the mid-1970s are reviewed. These trials used three distinctly different preparations made from hyaluronan of different average molecular weight, polydispersity and, consequently, different elastoviscous properties. These differences are demonstrated and the consequences on the potential efficacy of the preparations are discussed.

Influence of serotonin on the analgesic effect of granisetron on temporomandibular joint arthritis

THE influence of circulating serotonin (5-HT) on the effects of intra-articular administration of granisetron on temporomandibular joint (TMJ) pain was investigated in 11 patients with chronic polyarthritides. An analgesic effect superior to placebo has been shown previously.

The change in TMJ movement pain intensity was negatively correlated to circulating 5-HT; that is, the higher the 5-HT before injection, the greater the reduction of pain intensity. The resting pain intensity reduction was not related to 5-HT.

In conclusion, this study indicates a stronger short-term analgesic effect on TMJ movement pain by intra-articular administration of the 5-HT3receptor antagonist granisetron in patients with high levels of circulating 5-HT.

Characterization and opioid modulation of inflammatory temporomandibular joint pain in the rat

PURPOSE

Experimental inflammation of the rat temporomandibular joint (TMJ) is commonly used to study trigeminal nociceptive processing. This study describes spontaneous pain-related behaviors following TMJ inflammation in the rat. The ability of preemptive systemic morphine to attenuate behaviors as well as immediate-early gene expression in the trigeminal nucleus is described.

MATERIALS AND METHODS

Adult male Sprague-Dawley rats received an intra-articular injection of mustard oil (0% to 20%, 50 microL) and were observed for behavioral changes. Morphine sulfate (0 to 10 mg/kg SC) was given 30 minutes before mustard oil; this was reversed in one group with naltrexone hydrochloride (5 mg/kg SC). Two hours after injection rats were killed and perfused. Immunohistochemistry for the protein product of the immediate-early gene c-fos was performed, and brain stem sections including the trigeminal subnucleus caudalis were examined for positive nuclei.

RESULTS

Mustard oil inflammation of the rat TMJ induces dose-dependent, morphine-sensitive behaviors. Behaviors observed included excessive grooming of the region, a chewing-like behavior, and head shaking. Fos expression in the trigeminal subnucleus caudalis parallels changes in behaviors. Morphine dose dependently attenuates the number of behaviors, as well as Fos expression; this effect is reversed by the micro-opioid receptor antagonist naltrexone.

CONCLUSIONS

Mustard oil inflammation of the rat TMJ causes reliable behavioral changes, which may be quantified and, together with Fos expression, used to assess various experimental TMJ treatment modalities.

[The effects of L-NMMA on experimental temporomandibular joint osteoarthrosis in goats]

OBJECTIVE

To investigate the effects of repeated injections of L-NMMA on a goat model with osteoarthrotic temporomandibular joint (TMJ) disease.

METHODS

Eight goats were selected in this study. Bilateral TMJ osteoarthrosis (OA) was induced by injecting 0.5% collagenase. L-NMMA was injected into one side of TMJs at 4 weeks after collagenase injection (one time every three days). Another joint as control was simultaneously injected using 0.9% saline solution. All goats were killed at 12 weeks after collagenase injection. The TMJ specimens were harvested and processed for histological examination. Modified Mankin's grading score system was used for evaluating changes in the TMJ.

RESULTS

The control side of TMJs showed severe osteoarhrotic changes in the condyle whereas the L-NMMA-treated TMJs showed less degenerative alterations. The histologic score was 3.83 in the L-NMMA treated side, and 6.33 in the control. There was a significant difference in osteoarthrotic changes between the L-NMMA-treated and control TMJs (P < 0.01).

CONCLUSIONS

Repeated intra-articular injection of L-NMMA into TMJ may play a role in inhibiting TMJOA progression.