Outline
Some forms of physical therapy are used relatively frequently in the treatment of chronic musculoskeletal pain conditions, including the temporomandibular disorders. We found evidence that cold seems to be a useful treatment for postsurgical pain and swelling and that most patients being treated for most chronic musculoskeletal pain seem to do better with most forms of therapy. However, we agree with the authors of previous reviews that there is little evidence that these methods of management cause long-lasting reductions in signs and symptoms. Findings of recent clinical trials tend to support this conclusion, although evidence is beginning to accumulate that exercise programs designed to improve physical fitness have beneficial effects on chronic pain and disability of the musculoskeletal system.
Among the reports that we read, very few fulfilled the criteria that have been established for well-conducted clinical trials by authors like Chalmers et al.4 In addition, Chapman 5 and Clark et al.3 noted that most studies compared different forms of treatment and that most treatments included several forms of intervention; this makes interpretation risky and hampers efforts to draw valid conclusions.
REVIEWS OF PHYSICAL THERAPIES^
In a discussion of conservative treatments for chronic low back pain, Deyo 6 found some evidence of efficacy for spinal manipulation but none to support the use of any of the modalities that are commonly used for TMDs. Eight years later, Koes et al.7 reviewed studies of spinal manipulation and mobilization but concluded that the efficacy of these treatments had still not been demonstrated.
In a series of blind meta-analyses, Beckerman et al.8 studied many types of physical therapies for chronic back, neck, and shoulder pain, as well as for disorders of the knee. Low-intensity laser therapy appeared to have a short-term therapeutic effect in patients with myofascial pain, rheumatoid arthritis, and posttraumatic joint disorders. However, the authors could not draw conclusions concerning a minimum or optimum dose.
In a review of thermal agents and low intensity laser, Chapman 5 found little evidence to support the use of any of these therapies to achieve long-term pain relief but found that cold and short-wave diathermy appeared to have short-term analgesic effects.
Two task forces on low back pain found some evidence to support claims of efficacy for exercise programs.9, 10 On the basis of this evidence, Fordyce 10 has recommended active exercise programs that promote general physical fitness as “the best means of achieving lasting relief of both pain and disability.”
Although Clark et al.3 found in their review that evidence of the efficacy of physical therapy for TMDs was equivocal or lacking, they recommended that physical therapies be used in the treatment of TMDs because they believed that these therapies had been shown to be effective for other pain conditions. Although Dahlström 11 concluded that no particular conservative treatment method for TMD appeared to be more efficacious than any other, she pointed out that a large number of patients with TMDs appear to have been treated successfully. This point is consistent with the findings drawn from a meta-analysis of treatment for many forms of chronic pain by Malone and Strube.12 They detected a pattern that suggested “a uniform efficacy of treatments despite differences in types of pain treated, dependent measures used, outpatient status or patient characteristics.” The authors concluded that “the effectiveness of these treatments may be attributable not to the differences between treatments, but to the features they share in common.” These features include identification of the psychological factors that exacerbate pain, contact with an empathetic professional, and provision of hope for relief from symptoms.
We will now discuss key papers dealing with specific modalities.
THERMAL THERAPIES^
Hecht et al.13 compared the effectiveness of local applications of cold and heat in conjunction with exercise versus exercise alone on postsurgical pain of the knee. The application of cold with exercise was rated as providing significantly greater relief than the application of heat plus exercise or exercise alone, and swelling was also significantly decreased in the group that received the cold therapy. No other significant differences between groups were found. These results support Chapman's 5 conclusions that local application of cold can provide short-term relief of pain, possibly because of its analgesic effects and ability to reduce inflammation. The use of hot packs to reduce pain has almost no support in the literature.
In agreement with previous studies of ultrasound, Falconer et al.14 failed to show significant treatment effects immediately or 2 months after treatment in subjects with painful osteoarthritis of the knee.
ACUPUNCTURE^
It is believed that acupuncture decreases pain by stimulating the production of endogenous opiates. However, we found no evidence to suggest that acupuncture is truly efficacious in reducing or eliminating chronic musculoskeletal pain. Raustia and Pohjola 15 compared two groups of subjects with TMD; one group was treated with occlusal splints and the other with acupuncture. Johansson et al.16 later conducted the same study with use of a blind and randomized design. No between-treatment differences were found in either study.
List and Helkimo 17 conducted a similar study but found that the group receiving the acupuncture rated the relief they experienced as greater than that rated by the group with splints or a control group. Unfortunately, the three groups differed significantly in age, gender distribution, and duration of pain. In addition, members of the acupuncture group were seen more frequently by the therapist than were members of the other groups. A 1-year follow-up of the same subjects found that improvement in the acupuncture group had decreased, whereas improvement in the splint group had increased.18
LOW INTENSITY LASER^
Two meta-analyses on low intensity laser therapy for musculoskeletal disorders have been published.19, 20 Gam et al.20 concluded that laser therapy was not efficacious. Beckerman et al.19 were slightly more positive. Bertolucci and Grey 21 reported that laser therapy reduced pain and tenderness associated with degenerative disease of the TMJ more than placebo. However, it is hard to accept the assurance that patients were randomly assigned to the two groups, because the same data appeared in a three-group “randomized” study by the same authors.22
ELECTRICAL STIMULATION^
One study suggesting that there may be some beneficial effect of transcutaneous electrical nerve stimulation (TENS) comes from Graff-Radford et al.,23 who applied four different forms of TENS to “active” trigger points of myofascial pain subjects. Pain ratings were gathered before and after 10 minutes of treatment. Pain decreased for all groups, and post-treatment pain was significantly less in three of the TENS treatment groups than in the placebo and the fourth TENS group. Unfortunately, the level of pretreatment pain was significantly different between groups, and the groups that responded most to treatment were also those with the highest levels of pretreatment pain.
Deyo et al.24 compared TENS, sham TENS, TENS plus exercise, and sham TENS plus exercise in patients with chronic lower back pain. All four groups showed significant improvement in almost all outcomes during the 4-week trial, but 2 months later there were no differences between the groups that received TENS and sham TENS alone, and the authors concluded that TENS adds nothing to the beneficial effects of exercise. In a paper that included no data, Møystad et al.25 reported that conventional TENS, acupuncture-like TENS, and placebo TENS all led to significant improvement in pain and function during a 3-week trial.
Lewis et al.26 compared TENS, nonsteroidal anti-inflammatory drugs, and placebos in patients with osteoarthritis of the knee but found no between-group differences. However, they did show that all groups improved significantly during the trial and that this improvement began in the week preceding treatment.
In studies of TMDs, Block and Laskin 27 reported no significant between-group differences (TENS vs placebo) after 3 to 6 weeks of treatment. Taylor et al.28 tested an “inferential current” stimulator versus a placebo in subjects with chronic unilateral or bilateral jaw pain over a 3- to 9-day period. Pain decreased over time, but no between-group differences were detected for pain or for maximum opening. Linde et al.29 compared TENS with occlusal splints in subjects who had internal derangements and reported pain. There were few between-group differences, but the number of patients with at least a 50% reduction in pain was significantly less in the splint group than in the TENS group. The authors chose to emphasize the small differences in outcome between treatments, but we were more impressed by the similarities. Bertolucci and Grey 22 reported that TENS and low-power laser both gave better results than placebo during the 3 weeks of the trial. However, the comments made about “randomization” in the section on low-power laser also apply here.
MANIPULATION AND EXERCISE^
When combined with the short-term effects of cold to decrease pain, passive exercise and stretching may be useful in increasing range of motion (see the section on thermal therapies). Some evidence also suggests that exercise of the specific painful area is effective in strengthening the muscles, improving function, and reducing pain. Tegelberg and Kopp 30 ran parallel studies of jaw exercise versus a no-treatment control in subjects with rheumatoid arthritis and ankylosing spondylitis. Significant differences were detected for both conditions in mean maximal opening, but no between-group differences were detected for change in the subjective symptoms (pain, stiffness). However, the results of Dao et al.31 suggest that exercise must be used with caution. They measured pain levels of patients with TMDs before and after 3 minutes of chewing on wax and found that exercise gave relief to those whose pain levels were high but exacerbated low-level pain.
The strongest evidence of efficacy comes from studies of general exercise. No matter what the condition under study, treatments that aim to improve general physical fitness perform well. We found, as did other reviewers and two task forces on chronic low back pain, that exercise to improve general fitness will provide the greatest benefit.9, 10, 32, 33
DISCUSSION^
The goals of treatment for any chronic pain condition are undeniably reduction of pain and improvement of quality of life, which suggests that a treatment should be estimated for (1) its efficacy in reducing the pain and (2) its effectiveness in helping the patient to feel better.34 The latter may or may not coincide with pain reduction.
In this review we found that a wide variety of outcomes and interpretations of treatment success were used that were based primarily on pain reduction, as well as on changes in clinical or functional parameters. Ratings of perceived relief were sometimes used. The majority of the studies used validated measures of pain intensity as the primary outcome variable. Tenderness (or pressure pain) was often used as another outcome. However, most of the investigations did not use pressure algometers or attempt to standardize the stimulus. Furthermore, some investigators chose to palpate the painful site, others used diagnostic points (particularly in studies of fibromyalgia), and others chose trigger points.
Unfortunately, few studies considered improvement in quality of life as a measure of treatment success, even though psychosocial instruments have been developed to measure the impact of disease on oral and general health (e.g., Slade and Spencer,35 Adulyanon and Sheiham,36 and Leake 37). Such tools give more meaningful information on the efficacy of treatment than many traditional methods and should be incorporated in future trials.
According to Metcalfe,38 the care provided to a patient depends on whether that patient has an acute or chronic condition. For patients with an acute illness, treatments are the norm: they are usually discrete and simple, with short-term goals. “Treatment” is disease-centered care that is focused primarily on the pathophysiologic features of the condition. On the other hand, “management” is patient-centered care that involves a range of interventions directed toward reducing the physical, social, and psychological impact of a chronic condition. The goal of management is to reduce symptoms but also to improve well-being and quality of life. For chronic disease it is long-term efficacy that must be sought, and failure to provide posttreatment data was a significant shortcoming of most of the trials that we reviewed.
This failure to provide posttreatment data is particularly important in light of the trend that we and other reviewers noted towards efficacy during treatment no matter what therapy (including placebo) was used. Malone and Strube 12 have suggested that the efficacy of many therapies may be based on “their ability to reduce the fear and depression associated with pain.” We agree and believe that patients suffer less when they are better informed, are under care, and are less fearful of the future.
CONCLUSIONS^
No good evidence exists that any of the treatments under review are capable of curing or even significantly reducing symptoms of chronic musculoskeletal conditions, including TMDs. However, it appears that patients are helped while they are undergoing treatment, and that this does not depend on the specific form of therapy used. In other words, these forms of reversible, noninvasive therapy are better than no therapy, perhaps because patients do best when clinicians take the time to fully inform them about their condition and allay their fears.
The most promising strategies for long-term management of musculoskeletal chronic pain are based on exercise programs. These findings are encouraging, because these therapies should also be low in cost.
REFERENCES^
1. Glass EG, McGlynn FD, Glaros AG. A survey of treatments for myofascial pain dysfunction. J Craniomandibular Pract 1991;9:165-8. [Medline Link] [Context Link]
2. Glass EG, Glaros AG, McGlynn FD. Myofascial pain dysfunction: treatments used by ADA members. J Craniomandibular Pract 1993;11:25-9. [Medline Link] [Context Link]
3. Clark GT, Adachi NY, Dornan MR. Physical medicine procedures affect TMD disorders: a review. J Am Dent Assoc 1990;121:151-60. [Medline Link] [Context Link]
4. Chalmers TC, Smith H Jr, Blackburn B, Silverman B, Schroeder B, Reitman D, et al. A method for assessing the quality of a randomized control trial. Control Clin Trials 1981;2:31-49. [Medline Link] [Context Link]
5. Chapman CE. Can the use of physical modalities for pain control be rationalized by the research evidence? Can J Physiol Pharmacol 1991;69:704-12. [Medline Link] [Context Link]
6. Deyo RA. Conservative therapy for low back pain: distinguishing useful from useless therapy. JAMA 1983;250:1057-62. [Medline Link] [Context Link]
7. Koes BW, Assendelft WJ, van der Heijden GJ, Bouter LM, Knipschild PG. Spinal manipulation and mobilisation for back and neck pain: a blinded review. BMJ 1991;303:1298-303. [Medline Link] [Context Link]
8. Beckerman H, Bouter LM, van der Heijden GJ, de Bie RA, Koes BW. Efficacy of physiotherapy for musculoskeletal disorders: what can we learn from research? Review. Br J Gen Pract 1993;43:73-7. [Medline Link] [Context Link]
9. Spitzer WO, Leblanc F, Dupuis M, Abenham L, Belanger AY, Bloch R, et al. Scientific approach to the assessment and management of activity-related spinal disorders: Report of the Quebec Task Force on Spinal Disorders. Spine 1987;12(7S):S1-S59. [Context Link]
10. Fordyce WE. Back pain in the workplace management of disability in nonspecific conditions: Report of the Task Force on Pain in the Workplace of the Interaction. Seattle: IASP Press, 1995. [Context Link]
11. Dahlström L. Conservative treatment methods in craniomandibular disorder. Swed Dent J 1992;16:217-30. [Medline Link] [Context Link]
12. Malone MD, Strube MJ. Meta-analysis of non-medical treatments for chronic pain. Pain 1988;34:231-44. [Medline Link] [PsycINFO Link] [Context Link]
13. Hecht PJ, Bachmann S, Booth RE Jr, Rothman RH. Effects of thermal therapy on rehabilitation after total knee arthroplasty: a prospective randomized study. Clin Orthop 1983;178:198-201. [Medline Link] [Context Link]
14. Falconer J, Hayes KW, Chang RW. Effect of ultrasound on mobility in osteoarthritis of the knee: a randomized clinical trial. Arthritis Care Res 1992;5:29-35. [Medline Link] [CINAHL Link] [Context Link]
15. Raustia AM, Pohjola RT. Acupuncture compared with stomatognathic treatment for TMJ dysfunction, Part III: Effect of treatment mobility. J Prosthet Dent 1986;56:616-23. [Medline Link] [Context Link]
16. Johansson A, Wenneberg B, Wagersten C, Haraldson T. Acupuncture in treatment of facial muscular pain. Acta Odontol Scand 1991;49:153-8. [Medline Link] [Context Link]
17. List T, Helkimo M. Acupuncture and occlusal splint therapy in the treatment of craniomandibular disorders. Acta Odontol Scand 1992;50:375-85. [Medline Link] [Context Link]
18. List T, Helkimo M, Andersson S, Carlsson GE. Acupuncture and occlusal splint therapy in the treatment of craniomandibular disorders, Part I: A comparative study. Swed Dent J 1992;16:125-41. [Medline Link] [Context Link]
19. Beckerman H, de Bie RA, Bouter LM, De Cuyper HJ, Oostendrop RAB. The efficacy of laser therapy for musculoskeletal and skin disorders: a criteria-based meta-analysis of randomized clinical trials. Phys Ther 1992;72:13-21. [Medline Link] [CINAHL Link] [Context Link]
20. Gam AN, Thorsen H, Lonnberg F. The effect of low-level laser therapy on musculoskeletal pain: a meta-analysis. Pain 1993;52:63-6. [Medline Link] [PsycINFO Link] [Context Link]
21. Bertolucci LE, Grey T. Clinical analysis of mid-laser versus placebo treatment of arthralgic TMJ degenerative joints. J Craniomandibular Pract 1995;13:27-9. [Context Link]
22. Bertolucci LE, Grey T. Clinical comparative study of microcurrent electrical stimulation to mid-laser and placebo treatment in degenerative joint disease of the temporomandibular joint. J Craniomandibular Pract 1995;13:116-20. [Medline Link] [Context Link]
23. Graff-Radford SB, Reeves JL, Baker RL, Chiu D. Effects of transcutaneous electrical nerve stimulation on myofascial pain and trigger point sensitivity. Pain 1989;37:1-5. [Medline Link] [Context Link]
24. Deyo RA, Walsh NE, Martin DC, Schoenfield LS, Ramamurthy S. A controlled trial of transcutaneous electrical nerve stimulation (TENS) and exercise for chronic low back pain. New Engl J Med 1990;322:1627-34. [Medline Link] [Context Link]
25. Møystad A, Krogstad BS, Larheim TA. Transcutaneous nerve stimulation in a group of patients with rheumatic disease involving the temporomandibular joint. J Prosthet Dent 1990;64:596-600. [Medline Link] [Context Link]
26. Lewis B, Lewis D, Cumming G. The comparative analgesic efficacy of TENS and a non-steroidal anti-inflammatory drug for painful osteoarthritis. Br J Rheumatol 1994;33:455-60. [Medline Link] [Context Link]
27. Block SL, Laskin DM. The effectiveness of TENS in the treatment of unilateral MPD syndrome [abstract]. J Dent Res 1980;59(special issue):519. [Context Link]
28. Taylor K, Newton RA, Personius WJ, Bush FM. Effects of interferential current stimulation for treatment of subjects with recurrent jaw pain. Phys Ther 1987;67:346-50. [Medline Link] [CINAHL Link] [Context Link]
29. Linde C, Isacsson G, Jonsson BG. Outcome of 6-week treatment with TENS compared with splint on symptomatic TMD joint disk displacement without reduction. Acta Odontol Scand 1995;53:92-8. [Medline Link] [Context Link]
30. Tegelberg A, Kopp S. Short-term effect of physical training on temporomandibular joint disorder in individuals with rheumatoid arthritis and ankylosing spondylitis. Acta Odontol Scand 1988;46:49-56. [Medline Link] [Context Link]
31. Dao TTT, Lund JP, Lavigne GJ. Pain responses to experimental chewing in myofascial pain patients. J Dent Res 1994;73:1163-7. [Medline Link] [Context Link]
32. Minor MA, Hewett JE, Webel RR, Anderson SK, Kay DR. Efficacy of physical conditioning exercise in patients with rheumatoid arthritis and osteoarthritis. Arthritis Rheum 1989;32:1396-405. [Medline Link] [CINAHL Link] [Context Link]
33. Timm KE. A randomized-control study of active and passive treatments for chronic low back pain following L5 laminectomy. J Orthop Sports Phys Ther 1994;20:276-86. [Medline Link] [CINAHL Link] [Context Link]
34. McQuay HJ. Assessment of pain and effectiveness of treatment. In: Hopkins A, Costain D, editors. Measuring the outcomes of medical care. Oxford: The Royal College of Physicians of London, 1990:43-57. [Context Link]
35. Slade GD, Spencer AJ. Development and evaluation of the oral health impact profile. Community Dent Health 1994;11:3-11. [Medline Link] [Context Link]
36. Adulyanon S, Sheiham A. A new socio-dental indicator of oral impacts on daily performances [abstract]. J Dent Res 1996;75(special issue):231. [Context Link]
37. Leake JL. An index of chewing ability. J Public Health Dent 1990;50:262-7. [Medline Link] [Context Link]
38. Metcalfe DHH. Measurement of outcomes in general practice. In: Hopkins A, Costain D, editors. The outcomes of medical care. Oxford: The Royal College of Physicians of London, 1990:93-104. [Context Link]
Accession Number: 00043790-199701000-00026