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There are very few guidelines available to advise and inform the TMJ specialist, MD, or Dentist treating a patient with TMJ disease when management should include an injection of corticosteroid. And the guidelines that have been published with respect to the appropriate dosage and technique are woefully inadequate.

For example, in August of 2002 the Royal College of Dental Surgeons of Onterio published their ‘Guidelines’ for the diagnosis and management of temporomandibular disorders and related musculoskeletal disorders (http://www.rcdso.org/pdf/guidelines/guidelines_TMD_Jul09.pdf). On page 7 of this treatise it is noted that corticosteroids may be considered in a selective manner to aid in the diagnosis but a more specific guideline related to treatment is nowhere to be found.

Likewise, the American Society of Temporomandibular Joint Surgeons also published a guideline for the management of TMD. What is noted in relation to joint injection is that corticosteroid injection “can be effective in reducing capsulitis” (http://www.ncbi.nlm.nih.gov/pubmed/18835358). To support this opinion the publication sites Glen Clark’s review article on Physical Medicine procedures for treating TMJ that was published in JADA, 1990. No actual animal or clinical studies that have been published since 1990 are listed or cited as support in either document.

Even in textbooks that discuss the use of intra-articular injections of corticosteroids into the TMJ, it is acknowledged that the information provided is based on perception and opinion versus the results of prospective randomized controlled scientific studies (see Osteoarthrosis/osteoarthritis, Chapter 13; Temporomandibular Joint and Masticatory Muscle Disorders, Ed. G. A. Azrb, G.E. Carlsson, B.J. Sessle, N.D. Mohl, 2nd Edition, Munksgaard, 1994).

More recent textbooks have provided better information (e.g. J Fricton and E Schiffman’s chapter 20 in ‘Orofacial Pain; From Basic Science to Clinical Management’ Edited by J P Lund, G J Lavigne, R Dubner, and B J Sessle). Fricton and Schiffman state that “direct TMJ injections of corticosteroids are a strategy that should not be used in general dental practice; multiple injections are contraindicated since they have been associated in some cases with progression of degenerative joint disease” but even in this text offering there is virtually no information regarding actual treatment guidelines for when and how to perform TMJ corticosteroid injection.

The issue of guidelines is not trivial as patients are seeking answers publically to the question of injection efficacy. If you google TMJ Steroid Injections there are several blogs on the subject. One is a blog authored by Kiki on ‘Health Central - ChronicPainConnection.com) that requests information on steroid injection for the treatment of painful closed lock. There are 12 comments by patients with TMJ that are considering joint injection.

As one patient (mackymorg, 12/12/09) states: after “double jaw surgery” she experienced opening restriction and now she is hoping the steroid injections “will help”. For another (Missy, 10/07/10) the injection is termed her “last chance to try to get some relief” (http://www.heathcentral.com/chronic-pain/778/10938/tmj-steroid/). In each case patients are asking other patients if this treatment is effective and if it will provide pain relief.

In addressing the issue of guidelines, two important questions need to be reviewed: 1, is injection of corticosteroid into the TMJ effective in managing pain or dysfunction; and 2, what are the risks of injecting corticosteroid into the TMJ.

TMJ Intra-Articular Corticosteroid Injection Efficacy

The answer to the first question hinges, in part, on what may be causing the ‘TMJ’ problem. The term ‘TMJ’ is nonspecific. Although it should only be applied to specific conditions involving the jaw joint, in the real world patients often present with a constellation of pain symptoms that suggest problems involving not only the temporomandibular joint but also associated structures like the jaw musculature and other linked co-morbid conditions (e.g. tension HA).

Many facial, neck, and head pain problems can refer pain to the TMJ and this can confound the diagnosis of TMJ pathology (e.g. J Khan, SY Quek, Markman S. Nasopharyngeal carcinoma masquerading as TMJ orofacial pain. Quintessence Int. 2010. 41(5):387-389). And even with respect to TMJ disease, the various conditions that can involve the joint represent a heterogeneous group of abnormalities and rarely represent one clear cut easily defined problem.

So in patients with complex TMJ, multi-system, and co-morbid conditions the single or repeated injection of corticosteroid into the joint may not be an effective treatment in managing facial pain. The literature provides support for the idea that the diagnosis related to TMJ abnormality is important with respect to subsequent treatment joint injection efficacy.

Injection Related to Diagnosis

For example, if the cause of TMJ degenerative disease, based on fulfillment of clinical inclusion criteria and laboratory and radiologic findings, is juvenile idiopathic arthritis (JIA), several studies suggest that intra-articular injection of corticosteroid (triamcinolone) may significantly reduce pain in children (B Arabshahi, et al, Arthritis Rheum. 2006; 52:3563-3569; AM Cahill, et al, AJR AM J Roentgenol. 2007;188:182-186; S Ringold, et al. J Rheumatol. 2008; 35(6):1157-1164)).

In a retrospective chart review of all JIA patients seen at the University Pediatric clinic by S Ringold and colleagues from Children’s Hospital and Regional Medical Center, University of Washington School of Medicine, Seattle, Washington (see above reference), 25 individuals were identified as having had TMJ joint injections. The patients received 74 intra-articular corticosteroid injections on 47 occasions. The authors report that following corticosteroid injection and at follow-up, jaw opening was also observed to increase significantly but repeated injections only produced minimal response.

But for other conditions involving the TMJ the research is less clear with respect to the efficacy of injecting corticosteroid. T BiØrnland, A Giaerum, and A MØystad from the Department of Oral Surgery and Oral Medicine, Institute of Clinical Dentistry at the University of Oslo, Oslo, Norway report that in adult patients with TMJ osteoarthritis not associated with rheumatoid disease, a single intra-articular injection with sodium hyaluronate or two intra-articular injections with corticosteroids, 14 days apart, resulted in a significant reduction in pain. Unfortunately there were only 20 subjects in the study and there was no control group so the result of this preliminary research has to be interpreted with caution.

A number of other studies have shown that patients receiving steroid injection when the diagnosis is less specific with respect to TMJ inflammatory joint disease may not achieve as good a result as when injection is related to a specific TMJ arthritis. (P Alstergren, et al, of the Department of Clinical Oral Physiology/Center for Cliical Oral Science, Karolinska Institutet, Huddinge, Sweden; Acta Odontol Scand, 1996; 54(1):1-7).

It also may not be necessary to inject corticosteroid after arthrocentesis according to authors Y Han and colleagues from the Center for Temporomandibular Disorders and Orofacial Pain, Peking University School and Hospital of Stomatology, Beijing, China. In a recent RCT involving 90 patients with the diagnosis of non-reducing disk displacement who received arthrocentesis, half the group received a post injection of 0.5ml triamcinolone acetonide while the other half received a 0.5 ml saline solution. Patients were assessed repeatedly for 6 months. While those with the steroid injection were observed to have better pain control initially, at 3-4 weeks and six months after treatment there were no significant differences between the two groups for pain, maximal mouth opening, or for condylar bone change.

Comparative Studies

Comparison studies of intra-articular hyaluronic acid injection and corticosteroid TMJ injections suggest that there may be no difference between the two treatments in terms of progression or regression of osseous abnormalities as demonstrated by CT (A MØystad, BB Mork-Knutsen, T Bjornland, Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2008. 105(2)e53-60). And in terms of pain and dysfunction, when injected betamethasone was compared to sodium hyaluronate both drugs were observed to reduce symptoms and signs in TMJ patients with pain and dysfunction (S Kopp, et al, J Oral Maxillofac Surg, 1985; 43(6):429-435).

Long Term Studies

There are few studies assessing the long term effect of intra-articular injections of corticosteroid on temporomandibular joint arthritis. However Kopp, et al, published the results of a one and two year follow-up of TMJ arthritis patients that had received either corticosteroid (betamethasone) or sodium hyaluronate (Kopp, et al, J Oral Maxillofac Surg, 1987. Nov. 45(11):929-935). The authors report that both groups experienced significant reduction in subjective symptoms as well as clinical signs and that the bite force of patients had significantly improved at follow. Again, no control sham treatment was included in this prospective study so the results must be cautiously interpreted.

Systemic Reviews

There is only one Cochrane Database Systemic Review of intra-articular injection but the focus was essentially on the use of hyaluronate. Z Shi, C Guo,and M Awad from the Department of Oral Maxillofacial Surgery at the West China Stomatological hospital, Sichuan University, China, describe the results of their thorough review in the Cochrane Database 2003 (Cochrane Database Syst Rev. 2003(1): CD002970; http://www.ncbi.nlm.nih.gov/pubmed/12535445).

With respect to corticosteroid injection of the TMJ, they report that “three studies provided data from 124 patients for the comparison of hyaluronate with glucocorticoids…..and…..hyaluronate had the same short term and long term effects on the improvement of symptoms, clinical signs or overall conditions of the disorders as glucocorticoids”

Weaknesses in the Literature

First and foremost there are no randomized controlled trials assessing efficacy. One of many other weaknesses in the literature associated with TMJ steroid injection is the lack assessment of different drug formulations. As P Mountziaris, P Kramer, and A Mikos from Rice University point out in their review article ‘Emerging Intra-Articular Drug Delivery Systems for the Temporomandibular Joint’ (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2702533/), there are numerous corticosteroid formulations available for intra-articular injection that range from soluble agents to suspensions of relatively insoluble steroids such as triamcinolone hexacetonide. Presumably there could be different effects based on the use of the different preparations and dosage but there is virtually no research exploring these potential differences.

Another weakness is that there is virtually no data on the effect of different injection techniques. For example, most intra-articular steroid formulations typically include anesthetic (lidocaine) which presumably dilutes the volume of steroid and prevents potential complications but this hypothesis is essentially unsupported. There is also evidence that in one-third to one-half of injections the corticosteroid may be placed incorrectly (P Mountziaris - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2702533/).

Needle penetration of the joint cartilage that results in bleeding could compromise the integrity of the joint tissues leading to iatrogenic complications. However these potential problems have not been documented.

Radiographic imaging may help to monitor needle placement but is an expensive add-on to the cost of treatment and may represent a high enough financial hurdle that it prevents patients from pursuing this therapy. And there is evidence that MR imaging may be inaccurate in demonstrating anatomical landmarks (J Fritz, PL Pereira, JS Lewin. Pediatr Radiol, 2010; 40(12):1964-1965).

Risks of Intra-Articular injection

A number of anecdotal case reports suggest that there may be significant risk associated with the injection of corticosteroid into the temporomandibular joint. However the odds, while not appearing to be great, of developing a complication as a consequence of joint injection cannot be determined from the limited studies done to date and thus remain unclear. Lipoatrophy has been reported to result from a steroid injection into the temporomandibular joint (B Hugle, RM Laxer. Arthritis Theum. 2009; 60(11):3512).

C Schindler and colleagues from the Institute of Clinical Pharmacology, Medical Faculty, University of Technology, Dresden Germany report the case of a 29-year-old woman whose dental surgeon diagnosed capsulitis of the right TMJ and then injected 40mg triamcinolone into the joint. At four months a progressive trismus of the right TMJ developed and the intra-articular injection was repeated.

Subsequent MRI imaging of the joint revealed a disk dislocation and severe necrosis of the condyle. Socket deformation and bony apposition and complete destruction of the disk was further revealed during surgery. The patient experienced chronic pain. It was concluded that the severe complications involving the TMJ were the result of the intra-articular glucocorticoid injections (J Oral Pathol Med. 2005 Mar; 34(3):184-186).

In another study, the histopathological changes of the TMJ were assessed following intra-articular injection of triamcinolone acetonide. In this study of 149 patients with complaint of TMJ dysfunction subjects underwent non-surgical treatment for 6 months. Twenty three patients then had high condylectomies and 44 patients received two intra-articular injections of triamcinolone acetonide.

The histology of the joints was then evaluated on 44 specimens from 41 patients. What was observed histologically was damage to the fibrous layer in 100% of specimens from the steroid injected group, with damage to cartilage in 64% and the bone in 42% of cases. It was concluded that steroid could act as a lytic agent when injected into the joint.

The above human studies are consistent with what has been observed from previous animal studies. When rats were injected with a single dose of 1.2 mg/kg dexamethasone, significant resorption and active osteoclastic activity was observed at sacrifice (IE El-Hakim, IS Abdel-Hamid, A Bader. Clin Exp Rheumatol. 2002; 20(6):773-781). When rats with implanted articular cartilage were injected repeatedly with hydrocortisone acetate, triamcinolone acetonide as well as dexamethasone acetate, the recovered cartilage demonstrated apoptotic chondrocytes (Nakazawa F,Clin Exp Rheumatol. 2002 Nov-Dec;20(6):773-81).

In addition, there is evidence that intra-articular corticosteroid injection may cause mandibular growth inhibition in young rabbits (P Stoustrup, et all, Pediatr Rheumatol Online J, 2009 – (http://www.ncbi.nlm.nih.gov/pubmed/19200378).

Conclusion

This short review should underscore the primary problems associated with the development of ‘guidelines’ defining the appropriate use of intra-articular corticosteroid injection: there is just too little science evaluating short and long term efficacy, assessing the most efficient technique for drug delivery and the most effective formulation, and documenting the risks associated with repeated articular injection.

Nonetheless, it is clear that intra-articular injection of the TMJ with local anesthetic and corticosteroid may be useful with some forms of temporomandibular joint disease including juvenile rheumatoid arthritis and uncomplicated TM joint arthralgia associated with acute inflammation and osteoarthritis. However, as is noted by JJ Buescher in the American Family Physician (http://www.aafp.org/afp/2007/1115/p1477.html), “repeated intra-articular corticosteroid injections are not recommended”

This is an often repeated phrase in all texts and articles relating to corticosteroid injection into the TMJ and given the absence of adequate science to guide the decision making process, this advice should continue to be followed.

Submitted by Dr Jeff Burgess, Editor in Chief