Author Names
Asquini, G., Pitance, L., Michelotti, A., Falla, D.
Reviewer Name
Wes Pritzlaff, SPT
Reviewer Affiliation(s)
Duke University School of Medicine, Doctor of Physical Therapy Division
Paper Abstract
Background: Within physical therapy, manual therapy is known to be effective for managing temporomandibular disorders (TMDs). However, manual therapy is a broad term including different approaches applied to different body regions. Aims: This is the first systematic review that aims to evaluate the effectiveness of manual therapy applied specifically to the craniomandibular structures (Cranio-Mandibular Manual Therapy [CMMT]) on pain and maximum mouth opening in people with TMD. Material and methods: This systematic review was developed based on a pre-determined published protocol which was prospectively registered with PROSPERO (CRD42019160213). A search of MEDLINE, Embase, CINAHL, ZETOC, Web of Science, SCOPUS, PEDro, PubMed, Cochrane Library and Best Evidence, EBM reviews-Cochrane Central Register of Controlled Trials, Index to Chiropractic Literature ChiroAccess and Google Scholar databases was conducted from inception until October 2020. Randomised controlled trials comparing the effect of CMMT on pain and maximum mouth opening versus other types of treatment in TMDs were included. Two reviewers independently screened articles for inclusion, extracted data, assessed risk of bias with the revised Cochrane risk of bias tool for randomised trials and evaluated the overall quality of evidence with the Grading of Recommendations, Assessment, Development and Evaluations. Results: A total of 2720 records were screened, of which only 6 (293 participants) satisfied the inclusion criteria. All studies showed some concerns in risk of bias, except for one, which was high risk of bias. The overall quality of evidence was very low for all outcomes because of high heterogeneity and small sample sizes. All studies showed a significant improvement in pain and maximum mouth opening for CMMT from baseline in the mid-term, but only two showed superiority compared to other interventions. Given the high heterogeneity and small sample sizes of the included studies, a quantitative synthesis was not performed. Discussion and conclusion: There is the need for future high methodology research investigating different manual therapy techniques applied to different regions and different populations (e.g., chronic versus acute TMD) to determine what is most effective for pain and maximum mouth opening in patients with TMDs.
NIH Risk of Bias Tool
Quality Assessment of Systematic Reviews and Meta-Analyses
- Is the review based on a focused question that is adequately formulated and described?
- Yes
- Were eligibility criteria for included and excluded studies predefined and specified?
- Yes
- Did the literature search strategy use a comprehensive, systematic approach?
- Yes
- Were titles, abstracts, and full-text articles dually and independently reviewed for inclusion and exclusion to minimize bias?
- Yes
- Was the quality of each included study rated independently by two or more reviewers using a standard method to appraise its internal validity?
- Were the included studies listed along with important characteristics and results of each study?
- Yes
- Was publication bias assessed?
- Yes
- Was heterogeneity assessed? (This question applies only to meta-analyses.)
- Cannot Determine, Not Reported, Not Applicable
Key Finding #1
Due to heterogeneity in types of Cranio-Mandibular Manual Therapy (CMMT), temporomandibular disorders (TMD), comparison groups, and time points of assessment, there is very low quality of evidence supporting that Cranio-Mandibular Manual Therapy (CMMT) alone reduces pain and increases maximum mouth opening (MMO) by clinically significant amounts.
Key Finding #2
CMMT is suggested to be superior to sham therapy and self-care with exercise therapy, however, not superior to Kinesio tape or photobiomodulation therapy in reducing pain intensity (very low quality of evidence).
Key Finding #3
CMMT is suggested to be superior to sham therapy and no treatment, however, not superior to self-care with exercise, splint therapy, or photobiomodulation therapy in increasing maximum mouth opening (very low quality of evidence).
Key Finding #4
There are limited studies with a high methodology quality comparing CMMT alone to other interventions. More randomized controlled trials are needed to understand whether CMMT is superior to other treatments in reducing pain, increasing MMO, or improving other outcome measures in individuals with TMD.
Please provide your summary of the paper
This systematic review without meta-analysis (due to heterogeneity and small sample sizes) sought to evaluate the effectiveness of Cranio-Mandibular Manual Therapy (CMMT) on pain and temporomandibular joint (TMJ) range of motion in people with temporomandibular disorders (TMD). Primary outcome measures included maximum mouth opening (MMO; measured using a ruler) and pain intensity (measured via VAS or NPRS). While 2,720 articles were screened based on search criteria, only six were included in this systematic review. These articles were randomized controlled trials that did not combine CMMT with other interventions in treating patients with TMD. There was high heterogeneity in types of CMMT, TMD, comparison group, and time point of assessment of primary outcomes. CMMT techniques utilized across the six studies included intraoral myofascial therapy, oscillatory Grade IV TMJ mobilizations, facial massage, manual therapy applied to TMJ and masticatory muscles, and masticatory muscle trigger point release. TMD diagnoses across the six studies included chronic, acute, myogenic, arthrogenic, and mixed. Comparison groups to CMMT across the six studies included sham treatment, control group, self-care and exercise, splint, Kinesio tape, and photobiomodulation therapy. Lastly, the time of assessment of pain and MMO varied from immediate, five days, and from four weeks to one-year post-treatment across the six studies. All studies showed a moderate-to-high risk of bias based on the randomization procedure, failure to publish a study protocol a priori, the selection of the reported results, assessor awareness of interventions received, or small sample sizes. While all six included studies demonstrated clinically significant improvements in pain intensity and MMO, the quality of evidence is considered very low due to small sample sizes, high heterogeneity, and moderate-to-high risk of bias. These results suggest that CMMT may be more effective than sham therapy or no treatment, but do not suggest CMMT’s superiority to splint therapy, photobiomodulation, Kinesio tape, or self-care with exercise therapy in reducing pain or improving MMO at various time points in individuals with varying types of TMD. There were many limitations to this systematic review, including an inability to complete a meta-analysis due to bias, heterogeneity, and sample sizes.
Please provide your clinical interpretation of this paper. Include how this study may impact clinical practice and how the results can be implemented.
The limitations of moderate-to-high bias, heterogeneity in the type of CMMT, TMD, comparison group, and time point of assessment, and small sample sizes across the six studies result in conclusions with a very low quality of evidence. While the results of this systematic review support the use of CMMT to reduce pain intensity and improve MMO across time points in individuals with varying types of TMD, clinicians should be curious and critical about these recommendations. Clinicians may utilize motivational interviewing and shared-decision making to understand if an individual with TMD is appropriate for CMMT alone or in conjunction with other therapy to reduce pain and improve MMO. This systematic review identifies the lack of high-quality randomized controlled trials comparing CMMT alone compared to other treatments; therefore, more research is necessary to better understand how various types of CMMT may affect patients with various types of TMD at various time points post-treatment compared to various interventions.
