Research Review By Dr. Michael Haneline©

Audio:

Download MP3

Date Posted:

March 2023

Study Title:

Dry needling and upper cervical spinal manipulation in patients with temporomandibular disorder: A multi-center randomized clinical trial

Authors:

Dunning J, Butts R, Bliton P et al.

Author's Affiliations:

Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Universidad Rey Juan Carlos, Alcorcón, Spain; American Academy of Manipulative Therapy Fellowship in Orthopaedic Manual Physical Therapy, Montgomery, AL, USA; Department of Oral and Maxillofacial Surgery, Aristotle University of Thessaloniki, Greece

Publication Information:

Cranio 2022 Apr 12: 1-14. doi: 10.1080/08869634.2022.2062137z

Background Information:

Temporomandibular disorder (TMD) is a very common condition which affects 16% to 59% of the global population and has been shown to be the third most prominent pain condition world-wide (1). TMD is associated with a variety of factors, such as age, systemic illness, hormonal issues, habitual activity, occlusal variation, and psychosocial problems (2).

Patients with TMD typically manifest clinical signs and symptoms including pain in the temporomandibular joint (TMJ) and/or muscles of mastication, limited mandibular range of motion, crepitus, and functional limitation or deviation of the jaw. Headache and neck pain are also common symptoms associated with TMD (3, 4). TMD has been classified according to the following three main groups: 1) muscle disorders, 2) disc displacements, and 3) joint dysfunction (5).

A variety of treatment modalities for TMD are in use, which can be summarized as follows:
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) and muscle relaxants, which may improve symptoms (although significant adverse effects are possible when used long-term).
  • The long-term efficacy of surgery in patients with TMD is not adequately supported by research (6).
  • Electrophysical modalities such as laser therapy, ultrasound, TENS, iontophoresis, as well as isolated exercise have limited research support.
  • Interocclusal splint therapy for TMD has been reported to improve range of motion and decrease the intensity and frequency of jaw pain.
  • The evidence for the use of TMJ mobilization alone for TMD is inconclusive, although it is supported when combined with other conservative treatments, such as exercise.
  • Upper cervical spine mobilization or manipulation, whether alone, or included within a multi-modal treatment approach, such as exercise, mandibular mobilization, myofascial release, muscle energy, and/or tender-trigger point therapy, has been shown to significantly improve mouth opening and jaw pain (7).
  • Dry needling (DN) refers to the insertion of monofilament needles into muscles, ligaments, tendons, connective tissue, scar tissue, and peri-neural tissue. This technique has been shown to be effective for certain neuromusculoskeletal conditions, including TMD (8).
Dry needling and upper cervical spinal manipulation have each been found to be moderately effective for TMD; however, no studies have combined these treatments (as many do in clinical practice) to determine if there are any synergistic effects. Therefore, the objective of this study was to compare the combined effects of DN and upper cervical spinal manipulation to interocclusal splint therapy, NSAIDs, and TMJ mobilization in patients with TMD.

Pertinent Results:

120 patients with TMD (46.7% of those who were initially screened for eligibility) were selected to participate in the study and were randomly allocated into the dry needling (DN) and upper cervical spinal manipulation group (n = 62) or the interocclusal splint therapy, NSAIDs, and TMJ mobilization group (n = 58). The groups had similar baseline characteristics for all variables. The average number of treatment sessions for both groups were similar (6.29 and 6.55 treatments) and the average number of treatment sessions that included upper cervical spine manipulation was 5.23. No major adverse events were reported in either group.

Patients who received DN and spinal manipulation perceived greater reductions in average jaw pain intensity at 2 weeks (−13.9 reduction in the 100mm Visual Analog Scale [VAS]), 6 weeks (−19.0), and 3 months (−21.9) than those in the interocclusal splint therapy, NSAIDs, and non- thrust TMJ mobilization group.

There were large between-group effect sizes for the VAS (average jaw pain intensity over the last 7 days) at 2 weeks (standardized mean difference [SMD] = 0.81), 6 weeks (SMD = 1.07), and 3 months (SMD = 1.10) in favor of the DN and spinal manipulation group.

Active pain-free mouth opening also showed large between-group effect sizes at 2 weeks (SMD = 0.96), 6 weeks (SMD = 1.21), and 3 months (SMD = 1.61) in favor of the DN and spinal manipulation group.

Jaw pain intensity over the past 24 hrs (VAS) showed moderate to large between-group effect sizes in favor of the DN and spinal manipulation group; moderate (SMD = 0.71) at 2 weeks, large (SMD = 1.14) at 6 weeks, and large (SMD = 1.05) at 3 months.

Using a cutoff score of ≥ +5 on the Global Rating of Change (GROC), 44 patients (71%) in the DN and spinal manipulation group achieved a successful outcome compared to only 16 patients (28%) in the interocclusal splint therapy, NSAIDs, and TMJ mobilization group at 3 months follow-up. Calculating these data resulted in a number needed to treat (NNT) of 2.3 and based on a 50% improvement from baseline to 3 months in average jaw pain intensity over the last 7 days (VAS), the NNT was 1.8 in favor of the DN and spinal manipulation group.

Clinical Application & Conclusions:

The combination of dry needling and upper cervical spinal manipulation resulted in significantly greater improvements in jaw pain intensity and active pain-free mouth opening than a combination of interocclusal splint therapy, NSAIDs, and non-thrust joint mobilization to the TMJ.

Both upper cervical spine manipulation and dry needling have previously been shown to be effective in the treatment of TMD. These 2 treatments were combined in this study and proved to be superior to interocclusal splint therapy, NSAIDs, and TMJ mobilization. However, it is still unknown whether upper cervical spine manipulation alone or dry needling alone would be superior to the comparison interventions used in this study.

Based on the current study, clinicians should consider using dry needling and upper cervical spinal manipulation in patients with TMD.

Study Methods:

This was a randomized clinical trial in which data were collected from 10 outpatient physical therapy clinics in 10 different states in the United States. Consecutive patients with TMD were recruited and then screened for eligibility using the following criteria:
  1. At least 18 years of age,
  2. a clinical diagnosis of TMD consistent with the Revised TMD group 1 Muscle Disorders Diagnostic Algorithm (9),
  3. experienced TMD symptoms for at least 3 months, and
  4. intensity of TMD symptoms of at least 30 mm on the VAS (0–100 mm).
There were numerous exclusion criteria, as follows:
  • History of traumatic injury or surgery related to TMD
  • Symptoms indicative of disc displacement, arthrosis, or arthritis of the TMJ
  • Any primary headache (i.e., tension type headache or migraine) except cervicogenic
  • Fibromyalgia
  • Systematic disease (ex. rheumatoid arthritis, lupus erythematosus, or psoriatic arthritis)
  • Neurologic disorder (ex. trigeminal neuralgia)
  • Physical therapy, chiropractic, acupuncture, or splint treatment for TMD within the last 3 months
  • Taking prescription nonsteroidal anti-inflammatory drugs (NSAIDs) or taking non-prescription NSAIDs more than intermittently within the last 3 months
  • Sensitivity to acetylsalicylic acid with impaired coagulation or with ulcer, kidney, or liver dysfunction
  • Cardiac pacemaker, metal allergy, or severe needle phobia
  • Serious cardiovascular disease, psychiatric disorder, or cognitive impairment
  • Contraindications to dry needling or manual therapy
  • Currently pregnant
Ten physical therapists with an average of 10.1 years of clinical experience who were trained in DN for TMD, TMJ mobilization and upper cervical spine thrust manipulation delivered the interventions. They were also required to study a manual of standard operating procedures and attend a 6-hr training session on the study’s protocols.

Participating patients were examined to ensure that the affected TMJ matched the revised group 1 muscle disorders diagnostic algorithm; patients with group II and III TMD were ruled out. Included patients were randomly assigned to receive dry needling and upper cervical spinal manipulation or interocclusal splint therapy, NSAIDs, and non-thrust mobilization to the TMJ. The treating therapists were aware of patients’ group assignments.

Participants were provided up to 8 treatments over a 4-week period or fewer if symptoms resolved. In patients who received DN, acupuncture needles were inserted into the inferior head of the lateral pterygoid muscle, the superficial masseter muscle, the temporalis muscle, and the peri-articular capsule of the posterior TMJ. Depending on the sensitivity of the patient and/or the location of symptoms, patients had needles inserted into the superior head of the lateral pterygoid and the medial pterygoid. The inserted needles were manipulated bidirectionally to provoke a sensation of aching, tingling, deep pressure, heaviness, or warmth, and then left in place for 15-30 minutes.

High-velocity, low amplitude thrust manipulation was applied to C0-C1, C1-C2, or C2-C3 in patients in the experimental group during at least one treatment session. The treating therapist selected the spinal segment to manipulate at their discretion based on patient report and manual examination findings.

The primary outcome measure was average jaw pain intensity over the last 7 days, as measured by the VAS. Secondary outcomes included jaw pain intensity over the past 24 hours (VAS), active pain-free mouth opening (mm), and the 15-point Global Rating of Change (GROC). Outcomes were collected at baseline, 2 weeks, 6 weeks, and 3 months. Patients were asked to report any adverse event which lasted 1 week and was perceived as distressing and unacceptable to the patient, requiring further treatment.

Study Strengths / Weaknesses:

The main strength of this study was its adherence to good procedures in conducting a RCT. For instance, the participating physical therapists were trained in the trial procedures and techniques used, randomization was successful, patients were provided a sufficient number of treatments, and follow-up covered a 3-month period.

There were several limitations to this trial, however, including the lack of a placebo control group. Instead, different types of treatment were compared. In this case, the authors thought it would be advantageous to determine whether DN and upper cervical spinal manipulation works better or provides any different outcome than a commonly used conventional intervention, which is important to clinicians and TMD patients.

Another potential limitation was a risk of treatment bias due to all treating therapists being associated with the same post-graduate fellowship program in orthopedic manual physical therapy.

Lastly, different types of interocclusal appliances were likely used in the comparison group because they were prepared by different dentists based on the needs of each individual patient. The appliances may have involved adjustments at different frequencies for some patients than others which would have caused a degree of variability within the comparison group.

Additional References:

  1. Prasad SR, Kumar NR, Shruthi HR, et al. Temporomandibular pain. J Oral Maxillofac Pathol 2016; 20(2): 272-5.
  2. Svensson P, Kumar A. Assessment of risk factors for oro-facial pain and recent developments in classification: implications for management. J Oral Rehabil 2016; 43(12): 977-89.
  3. Speciali JG, Dach F. Temporomandibular dysfunction and headache disorder. Headache 2015;55(1):72-83.
  4. Bragatto MM, Bevilaqua-Grossi D, Regalo SC, et al. Associations among temporomandibular disorders, chronic neck pain and neck pain disability in computer office workers: a pilot study. J Oral Rehabil 2016; 43(5): 321-32.
  5. Harrison A, Thorp J, Ritzline P. A proposed diagnostic classification of patients with temporomandibular disorders: implications for physical therapists. J Orthop Sports Phys Ther 2014; 44(3): 182-97.
  6. Jerjes W, Upile T, Abbas S, et al. Muscle disorders and dentition-related aspects in temporomandibular disorders: controversies in the most commonly used treatment modalities. Int Arch Med 2008; 1(1): 23.
  7. La Touche R, Martinez Garcia S, Serrano Garcia B, et al. Effect of manual therapy and therapeutic exercise applied to the cervical region on pain and pressure pain sensitivity in patients with temporomandibular disorders: a systematic review and meta-analysis. Pain Med 2020; 21(10): 2373-84.
  8. Dunning J, Butts R, Mourad F, et al. Dry needling: a literature review with implications for clinical practice guidelines. Phys Ther Rev 2014; 19(4): 252-65.
  9. Look J, Schiffman E, Truelove E, et al. Reliability and validity of axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) with proposed revisions. J Oral Rehabil 2010; 37(10): 744-59.

Contact Tech Support  Contact Dr. Shawn Thistle
 
RRS Education on Facebook Dr. Shawn Thistle on Twitter Dr. Shawn Thistle on LinkedIn Find RRS Education on Instagram RRS Education (Research Review Service)