Home About us Editorial board Ahead of print Current issue Archives Submit article Instructions Subscribe Search Contacts Login 
  • Users Online: 638
  • Home
  • Print this page
  • Email this page


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2014  |  Volume : 26  |  Issue : 2  |  Page : 139-144

Evaluation of TENS therapy and Placebo drug therapy in the management of TMJ pain disorders: A comparative study


1 Department of Oral Medicine and Maxillofacial Radiology, Post Graduate Institute of Dental Sciences (PGIDS), Rohtak, Haryana, India
2 Department of Oral Medicine and Maxillofacial Radiology, Guru Nanak Dev Dental College, Sunam, Punjab, India
3 Department of Oral Medicine and Maxillofacial Radiology, DJ College of Dental Sciences and Research, Modinagar, India
4 Department of Oral and Maxillofacial Surgery, Saraswathi Dental College, Lucknow, Uttar Pradesh, India

Date of Submission20-May-2014
Date of Acceptance02-Aug-2014
Date of Web Publication30-Oct-2014

Correspondence Address:
Harneet Singh
Department of Oral Medicine and Maxillofacial Radiology, Post Graduate Institute of Dental Sciences (PGIDS), Rohtak, Haryana
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0972-1363.143685

Rights and Permissions
   Abstract 

Background: In recent times, transcutaneous electrical nerve stimulation (TENS) therapy and placebo drug therapy have been studied widely in the management of temporomandibular joint (TMJ) pain; but at the individual level. Thus, it was required to compare the efficacy of TENS and placebo drug therapy in patients with TMJ pain disorders. Aims: To determine the effectiveness of TENS therapy and placebo drug therapy in the treatment of TMJ pain disorders and to compare the efficacy of both. Settings and Design: A comparative study was done with 40 subjects reporting with the chief complaint of TMJ pain by dividing them into two groups through randomization. Materials and Methods: Subjects of either sex in the age group of 18-60 years and diagnosed with TMJ pain disorders were considered and divided into two equal groups of 20 patients each as Group I and Group II. Group I patients were advised TENS therapy once in a week for 4 weeks and were followed up in the fifth week. In Group II, placebo was given once daily for 4 weeks and follow-up was done in the fifth week. TMJ pain before, during, and at the completion of the treatment was measured in terms of Visual Analogue Scale (VAS). Statistical Analysis: Z-test for proportion and one-way analysis of variance (ANOVA) were used. Results: A significant improvement in the tenderness of muscles and TMJ and for maximum mouth opening bilaterally was observed in Group I during different visits. It was also observed that the average values for pain and tenderness of the muscles and TMJ in TENS therapy for the different visits including follow-up were less compared to the values in placebo drug therapy. Conclusion: TENS therapy proved to be one of the widely and most effectively used treatment modalities with its multifaceted approach toward the treatment of the TMJ pain disorders as compared to placebo therapy.

Keywords: Myolax, placebo, transcutaneous electrical nerve stimulation, Visual Analogue Scale


How to cite this article:
Singh H, Sunil MK, Kumar R, Singla N, Dua N, Garud SR. Evaluation of TENS therapy and Placebo drug therapy in the management of TMJ pain disorders: A comparative study . J Indian Acad Oral Med Radiol 2014;26:139-44

How to cite this URL:
Singh H, Sunil MK, Kumar R, Singla N, Dua N, Garud SR. Evaluation of TENS therapy and Placebo drug therapy in the management of TMJ pain disorders: A comparative study . J Indian Acad Oral Med Radiol [serial online] 2014 [cited 2019 Apr 18];26:139-44. Available from: http://www.jiaomr.in/text.asp?2014/26/2/139/143685


   Introduction Top


Temporomandibular disorders (TMDs) are one of the most common chronic orofacial pain conditions. The term refers to a cluster of disorders characterized by pain in the preauricular area, temporomandibular joint (TMJ), or in the region of muscles of mastication; limitation or deviation in mandibular range of motion; and clicking in the TMJ during mandibular function. [1] A variety of therapeutic modalities have been proposed for the management of individuals with the TMDs, such as orthopedic stabilization, intraoral appliances, behavioral therapy, and pharmacological modalities. In recent times, transcutaneous electrical nerve stimulation (TENS) therapy and placebo drug therapy have been studied widely; but at the individual level. Thus, it was required to compare the efficacy of TENS and placebo drug therapy in patients with TMJ pain disorders.


   Materials and Methods Top


Forty subjects of either sex in the age group of 18-60 years reporting to the Department of Oral Medicine and Radiology with the complaint of TMJ pain were included in the study. Patients diagnosed with TMJ pain disorders by clinical examination and radiographic evaluation using panoramic and transcranial radiographs of TMJ (both sides - open and closed) to rule out any bone changes were considered. Patients with orofacial pain, especially in the pre-auricular region, during function and palpation, tenderness in one or more muscles of mastication, tense or stiff muscles, and/or limited mouth opening were included in the study. Patients with definite radiographic changes with pathological conditions involving TMJ and other systemic diseases were excluded. Patients with cardiac pacemakers and cardiac arrhythmia, pregnancy, any type of malpositioning of teeth or malocclusion other than Class I, history of seizures and vascular disorders, brain tumor or neurological disease involving head and neck like Bell's palsy, multiple sclerosis, and Taurette's syndrome, abnormal bruising or bleeding disorders, and patients with undiagnosed dental pain or with skin lesions or facial abrasions, especially at the site of electrode placement, were also excluded from the study.

Detailed specific examinations for signs and symptoms of TMDs were carried out as suggested by the Research Diagnostic Criteria for Temporomandibular Disorders by Dworkin and LeResche in 1990. [2] Clinical parameters such as masticatory muscles and TMJ tenderness were evaluated using Visual Analogue Scale (VAS). Maximum mouth opening (i.e., maximum interincisal distance) without pain (in mm) was also recorded. Patients of either sex were divided into two equal groups of 20 patients each with one group as "TENS group" (Group I) and other as "placebo group" (Group II). Group I patients were advised TENS therapy once in a week for a period of four consecutive weeks and were followed up in the fifth week to know any symptomatic changes. A pocket-sized minor TENS unit with power supply of 6 V DC, pulse frequency range of 2-50 Hz ±10%, and maximum current output of 15 mA with 500 W load was used for 30 min per sitting. In Group II, placebo inert tablets (Myolax) [3] containing starch, dicalcium phosphate (DCP), lactose, modified starch (MS), talcum, etc., which were declared as completely inactive ingredients by the manufacturer (Sky Labs, Rohtak, India), were given once daily for 7 days for four consecutive weeks and follow-up was done for any changes in symptomatic effects of the patients in the fifth week. TMJ pain before the treatment, during treatment, and at the completion of the treatment was measured in terms of VAS in both the groups and evaluation with respect to the given parameters was done. Ethical approval was obtained from the regional committee for use of both the placebo drug and TENS therapy in patients. An informed consent was also obtained from the patients after explaining them in detail about the advantages, disadvantages (if any), and effects of the treatment protocol being followed in the study.

Statistical analysis

VAS findings were divided under clinical parameters such as masticatory muscles, TMJ tenderness, and maximum mouth opening (i.e., maximum interincisal distance) without pain (in mm). Tests used for the statistical analysis were Z-test for proportion, one-way analysis of variance (ANOVA) test, and Chi-square test. The level of significance for each test statistic was kept at 1%. If the calculated value was more than the tabulated value, then P < 0.01, i.e., a significant difference was observed. If the calculated value was less than the tabulated value, then P > 0.01, i.e., no significant difference was observed between groups at 1% level of significance.


   Results Top


All the values in TENS and placebo therapy groups for pain, tenderness of the muscles and TMJ, and mouth opening were expressed in terms of Mean ± SD, respectively. It was observed that average values for pain and for tenderness of the muscles and TMJ in TENS therapy at the different visits including follow-up were less than the values in placebo drug therapy (i.e., P < 0.01). Further, it was observed that in TENS therapy, there was continuous improvement at different visits for pain, tenderness of muscles and TMJ, and maximum mouth opening, respectively. Also, by applying Z-test for proportion and one-way ANOVA, a significant difference was observed in the value of pain, tenderness of masticatory muscles, TMJ, and maximum mouth opening at 1% level of significance for each visit.


   Discussion Top


Pain, muscle tenderness, or alterations of the mandibular movements are the cardinal symptoms of TMJ pain dysfunction. For the treatment of such TMJ pain dysfunctions, a wide variety of therapeutic modalities have been offered, but there is still scarcity of clinical trials, especially randomized controlled clinical studies, to suggest appropriate management of these subjects. Various therapies appear to result in similar improvements in pain and dysfunction and caution is urged with regard to use of invasive and other irreversible treatments, particularly in the initial management of TMD subjects. [4]

TENS may act by neurologic, physiological, psychological, and pharmacological mechanisms. It is widely used to relieve acute and chronic pain and in various conditions like back pain, neck pain, phantom limb pain, extremity pain, etc., but studies on orofacial pain relief are few. [5]

Placebo drug therapy can be used as a psychological instrument in the therapy of certain mental illnesses, while dealing with neurotic subjects, to determine the effects of drugs in experimental work, and also as a tool in the mechanisms of drug action. Placebos are most effective when stress is a factor; thus, a study was conducted to evaluate the efficacy of both TENS and placebo in the treatment modalities of TMJ pain disorders and compare them. Therefore, the present study was conducted to evaluate the efficacy of TENS therapy and placebo drug therapy in 40 subjects of TMJ pain disorders.

Age distribution

In the present study, distribution of age was between 18 and 60 years, which were further divided into five subgroups. In this study, subjects of the second age group, i.e., between 21 and 30 years, consisted of 24 subjects of the total data, in which 6 males and 10 females were treated by TENS therapy and 2 male and 6 female subjects were treated with placebo drug therapy. This observation is consistent with the studies done by Jensen (1993) who stated that TMJ pain disorders commonly occurred in second and third decades of life. Similarly, in our study, 60% of the subjects with TMJ pain were of the same age group, i.e., between 20 and 30 years of age. Okeson et al. in 2003, stated that the common age of occurrence was in the second to fourth decades of life which is similar to the present study. [6]

Sex distribution

The study comprised a total of 40 subjects, of whom there were 14 male subjects; of these, 6 male subjects were treated with TENS therapy and 8 male subjects with placebo drug therapy. Remaining 26 subjects were female subjects, of whom 14 female subjects were treated with TENS therapy and 12 female subjects with placebo drug therapy. The male and female subjects were included in the ratio of 0.538:1 which correlates with other studies conducted by Riden (1986) [7] who reported that TMJ pain disorders commonly occurred in women under the age of 30. Juniper (1986) [8] and Linde et al. (1995) [9] documented that females were more affected by TMJ pain disorders than males.

Evaluation of pain

On intergroup comparison, significant pain reduction was observed in both Group I and Group II. TENS therapy group showed 87.5% reduction in pain, which was more effective than the placebo drug therapy group, which showed 76.76% reduction in relieving pain after the first visit. However, after the fourth visit, the percentage difference in pain reduction was found to be 20.3% (P < 0.003) and at the follow-up visit (fifth visit), it slightly came down to 17.6% (P < 0.0008) as the treatment was stopped for 1 month. Thus, it was proved that TENS therapy was a better modality for the treatment of continuous pain in TMJ pain disorders. In 1990, Moystad et al. [5] reported that subjects treated for TMJ rheumatoid arthritis with TENS and placebo TENS therapy method showed no statistically significant difference in reduction of pain. In 1972, Laskin and Green [3] observed 52% improvement in the total number of subjects who were given placebo drug named "Myolax" for TMJ pain, which is similar to our study in which there was 76.76% improvement in the pain. In 1999, Johnson and Tabassam [10] observed that TENS therapy was significantly better than placebo TENS in subjects with pain in TMJ region, which is similar to our study which also showed that TENS therapy is better than placebo drug therapy in relieving pain in the TMJ region. This significant reduction in TMD pain in subjects belonging to placebo group in our study could be attributed to placebo effects of drug therapy, as its provision is an expression of reassurance and care on the part of the therapist [Figure 1].
Figure 1: Comparison of pain reduction in both TENS and placebo drug therapy

Click here to view


Muscles and joint tenderness

A significant difference of improvement in tenderness of the muscles was seen between both the treatment modalities. The percentage difference of reduction in tenderness of masseter muscle on comparing TENS therapy and placebo drug therapy at the first visit was 0.41%. At the fourth visit of the treatment, the difference improved to 22.5% with P <0.0026 and 30.09% at the follow-up (fifth visit) with P < 0.0013 [Figure 2]. Medial pterygoid showed a percentage difference of 8.5% in reduction of tenderness on comparing TENS therapy and placebo drug therapy at the first visit; at the fourth visit of the treatment, the percentage difference in muscle tenderness improved to 31.68% (P < 0.0039) and gradually increased to 57.64% (P < 0.0019) at the follow-up (fifth visit) [Figure 3]. Lateral pterygoid showed a percentage difference of 2.08% in reduction of tenderness on comparison of TENS therapy and placebo drug therapy at the first visit; this difference was reduced to 1.28% at the second visit. At the fourth visit of the treatment, the difference improved to 26.59% (P < 0.0082) and 30.09% (P < 0.0072) at the follow-up (fifth visit), which is highly favorable for the TENS therapy [Figure 4]. Temporalis muscle showed a percentage difference of 6.66% in reduction of tenderness on comparison of TENS therapy and placebo drug therapy at the first visit. At the fourth visit of treatment, the difference improved to 18.75% with P < 0.0072 and 42% with P < 0.0058 at the follow-up (fifth visit) [Figure 5].
Figure 2: Percentage difference in reduction of masseter muscle tenderness

Click here to view
Figure 3: Percentage difference in reduction of medial pterygoid muscle tenderness

Click here to view
Figure 4: Percentage difference in reduction of lateral pterygoid muscle tenderness

Click here to view
Figure 5: Percentage difference in reduction of temporalis muscle tenderness

Click here to view


TMJ showed a percentage difference of 17.8% in reduction of tenderness on comparison of TENS therapy and placebo drug therapy at the first visit. At the fourth visit of the treatment, the difference improved to 15.76% (P < 0.0507) which was non-significant and 35.81% at the follow-up (fifth visit) with P < 0.0019, which was significant (P < 0.01) [Figure 6].
Figure 6: Percentage difference in reduction of TMJ tenderness

Click here to view


There are only a few studies on TENS therapy evaluating the efficacy on masticatory muscles tenderness. Similar to our study, Giessler and McPhee [11] also observed in 1986 that TENS therapy was effective in relieving muscle pain. In 1992, List and Helkimo [12] in 2003, who used TENS therapy in subjects with primarily myogenic craniomandibular disorders, found that 57% of subjects benefited subjectively (P < 0.01) and clinically (P < 0.001), which is similar to our study where it was observed that the decrease in tenderness was slightly more in active TENS therapy group than in placebo group and the difference was statistically significant (P < 0.01).

Maximum mouth opening

Comparison of TENS therapy and placebo drug therapy groups showed that the percentage difference in the maximum mouth opening at the first visit was 9.30%, which slightly improved to 9.89% at the second visit. At the third visit, percentage difference in the maximum mouth opening was reduced to 5.20%. In 1984, Epstein [13] reported that subjects responded very well to the initial treatment of placebo drug therapy due to the psychological effects of the placebo, but in the following visits it was reduced to the normal response which is similar to the present study. At the fourth visit, percentage difference in the maximum mouth opening was 5.35% in favor of TENS therapy, which further reduced to 3.51%. In 1994, Mehta et al. [14] observed an increase in the interincisal distance in subjects with TMJ pain after TENS therapy, which is similar to our study, and no significant increase in mouth opening after placebo drug therapy [Figure 7].
Figure 7: Percentage difference in maximum mouth opening

Click here to view



   Summary and Conclusion Top


The present study was conducted to determine and compare the effectiveness of active TENS and placebo drug therapy in TMJ pain disorders. The study showed highest prevalence of TMD signs and symptoms from the second to fourth decades of life (60%).

In this study, a significant pain reduction was observed in both TENS and placebo drug therapy groups. In both TENS group and placebo group, there was gradual but significant decrease in tenderness in all masticatory muscles and TMJ and an increase in mean mouth opening. In this study, we conclude that the effect of TENS therapy has proved to be better than the effect of placebo drug therapy in reduction of intensity of pain, tenderness of the muscles, and opening of the mouth in TMJ pain disorders. Further studies are required to be carried out to determine the efficacy of TENS therapy and placebo drug therapy in TMJ pain disorders among patients of either sex and in a larger sample of subjects. Subjects of different age groups can be studied to compare the efficacies of TENS and placebo drug therapies in variable pain conditions of the TMJ. Further studies are also required to compare the efficacy of TENS and other treatment modalities such as non-steroidal anti-inflammatory drugs, muscle relaxants, and other physical methods that can be used.

 
   References Top

1.
Dworkin SF, Huggins KH, LeResche L, Von Korff M, Howard J, Truelove E, et al. Epidemiology of signs and symptoms in temporomandibular disorders: Clinical signs in cases and controls. J Am Dent Assoc 1990;120:273-81.  Back to cited text no. 1
    
2.
Dworkin SF, LeResche L, DeRouen T, Von Korff M. Assessing clinical signs of temporomandibular disorders: Reliability of clinical examiners. J Prosthet Dent 1990;63:574-9.  Back to cited text no. 2
    
3.
Laskin DM, Greene CS. Influence of the doctor-patient relationship on placebo therapy for patients with myofascial pain-dysfunction (MPD) syndrome. J Am Dent Assoc 1972;85:892-4.  Back to cited text no. 3
[PUBMED]    
4.
Management of temporomandibular disorders. National Institutes of Health Technology Assessment Conference Statement. J Am Dent Assoc 1996;127:1595-606.  Back to cited text no. 4
[PUBMED]    
5.
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.  Back to cited text no. 5
    
6.
Okeson JP. Management of Temporomandibular Disorders and Occlusion. 5 th ed. St. Louis, MO: CV Mosby; 2003. p.8.  Back to cited text no. 6
    
7.
Riden DK. A clinical approach to pain: 2. Extraoral structures. Dent Update 1986;13:439-46, 448-9.  Back to cited text no. 7
    
8.
Juniper RP. Temporomandibular joint dysfunction: Facts and fallacies. Dent Update 1986;13:479-80, 482, 484 passim.  Back to cited text no. 8
[PUBMED]    
9.
Linde C, Isacsson G, Jonsson BG. Outcome of 6-week treatment with transcutaneous electric nerve stimulation compared with splint on symptomatic temporomandibular joint disk displacement without reduction. Acta Odontol Scand 1995;53:92-8.  Back to cited text no. 9
    
10.
Johnson MI, Tabasam G. A double blind placebo controlled investigation into the analgesic effects of inferential currents (IFC) and transcutaneous electrical nerve stimulation (TENS) on cold-induced pain in healthy subjects. Physiotherapy Theory Pract 1999;15:217-33.  Back to cited text no. 10
    
11.
Geissler PR, McPhee PM. Electrostimulation in the treatment of pain in the mandibular dysfunction syndrome. J Dent 1986;14:62-4.  Back to cited text no. 11
[PUBMED]    
12.
List T, Helkimo M. Acupuncture and occlusal splint therapy in the treatment of craniomandibular disorders. II. A 1-year follow-up study. Acta Odontol Scand 1992;50:375-85.  Back to cited text no. 12
    
13.
Epstein JB. Understanding placebos in dentistry. J Am Dent Assoc 1984;109:71-4.  Back to cited text no. 13
[PUBMED]    
14.
Mehta N, Kugel G, Alshuria A, Sands M, Forgeione A. Effect of electronic anesthesia T.E.N.S. on T.M.J. and orofacial pain. (Abstract 2054). J Dent Res1994;73:358.  Back to cited text no. 14
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

   Abstract Introduction Materials and Me... Results Discussion Summary and Conc... Article Figures
  In this article
 References

 Article Access Statistics
    Viewed1507    
    Printed42    
    Emailed0    
    PDF Downloaded429    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]