Results
The study selection process is described in the flowchart in Figure 1.
Initial screening retrieved 44 studies in MEDLINE|PubMed, 82 in
Web of Science, 10 in Cochrane Library, 38 in Embase, 150 in Scopus and
two in LILACS|VHL. Searching other sources and manual-searching
did not add any studies to this overview. After excluding duplicate
records, 314 articles were analyzed in the title and abstract reading.
Seven articles were selected to read the full text and apply the
exclusion criteria. Of these, a systematic review was excluded as it
included patients with disc displacement with reduction in the analysis.
The level of agreement between reviewers was almost perfect (κ ≥ 0.81)
for all databases consulted.
Six articles were included in this overview, five systematic reviews
with meta-analyses7-10,12 and a qualitative
review.11 Two articles included only randomized
controlled trials (RCTs),9,11 two articles included
RCTs and quasi-randomized clinical trials
(q-RCTs)8-10,12 and one article included RCTs, q-RCTs
and case series in the analyses.7 Only three articles
described the male: female proportion of the sample, with females being
predominant in the three articles.8,9,11 As for the
diagnosis of DDwoR, different criteria were reported in the articles:
Wilkes staging,8,10 American Association of Orofacial
Pain (AAOP),10 Research diagnostic criteria for
temporomandibular disorders (RDC/TMD) 10, Diagnostic
criteria for temporomandibular disorders
(DC/TMD),11,12 and Magnetic Resonance Imaging
(MRI).9,11 One study did not describe the diagnostic
criteria for participants.7 No secondary studies
described the duration of TMD or whether previous treatment for this
condition was performed (Table 2).
This overview showed that systematic reviews have confirmed
methodological heterogeneity in the clinical studies. Furthermore, the
meta-analyses showed statistical heterogeneity.7-10,12In general, the studies investigated the following comparisons:
comparison between different non-invasive
modalities;8-10 non-invasive versus minimally invasive
modalities;10,12 non-invasive versus invasive
modalities;8-10 minimally invasive versus invasive
modalities;7,10 and comparison between invasive
modalities.7-10 Outcomes reported in secondary studies
were: improvement assessed by the patient7; reduction
of pain8; frequency, intensity and duration of pain
events9; symptom remission9;
mandibular function; TMJ pain intensity10-12; and
maximum mouth opening (MMO)7,8,10-12(Table 2).
Follow-up time for patients varied between studies between 10 minutes
(only one primary study) and 60 months. Most of the articles included
assessed the risk of bias within studies using the Cochrane’s tool; none
of the primary studies had a low risk of bias in all
domains.8-10,12 One article used the PEDro scale and
noted that only 5:10 primary studies showed high methodological quality
with scores ranging from 7 to 8 points.11 One article
did not report the risk of bias analysis of the included studies (Table
2).7
Tables 3 and 4 (Table 3 and 4) present descriptive data and results of
pairwise comparisons of different treatment modalities for DDwoR
reported by secondary studies included in this overview.
Comparisons such as “rehabilitation” vs “medical
management”,8 “physical medicine” vs “palliative
care”,8 “physical medicine” vs
“controls”,8-10 “palliative care” vs
“physiotherapy” vs “no treatment”,9 revealed the
absence of significant difference in the improvement of
pain8-10 and/or mandibular
function.8 Comparing “mandibular manipulation” vs
“no treatment”, pain improvement and MMO were significantly greater in
patients who received mandibular manipulation.10 “Jaw
exercises” vs “education” showed no significant difference in pain
and MMO improvement.10 Comparing “self-management”
(self-exercises + self care/medication) vs “no treatment”,
“self-care” represented a significant improvement in pain and MMO
compared to “no treatment”.10
Comparing ”self-care” (self-care + self-care/non-steroidal
anti-inflammatory drugs) vs ”splint”: although there was a greater
reduction in pain intensity in the ”self-care” group in the short term,
the difference was not statistically significant.10For MMO, ”self-care” was more effective than
”splint”.10 Comparing ”immobilization” vs ”information
and pain medication as needed”, pain reduction was less frequent in the
”immobilization” group in the long-term.10
The number of patients with ≥ 50 % pain reduction was significantly
higher in the ”splint” group compared to the ”transcutaneous electrical
nerve stimulation (TENS)” group; however, there was no statistically
significant difference between both interventions for
MMO.10
”Combination therapy” (splint plus exercise +
self-care/medication/education) compared to ”Education” (only) or
”self-care” (self-care/medication/education ± self-care) showed no
significant difference in pain improvement and MMO.10”Manual therapy and exercise interventions” vs ”splints” showed no
significant difference for pain improvement; however, the improvement in
MMO was significantly greater for ”manual therapy and exercise
interventions”.11
There was no statistically significant difference in the effects of
”combination of splint plus jaw exercises” compared to ”splint” for
short-term pain. For MMO, however, there was a statistically significant
difference in favor of combined treatment.10
Comparing ”active pulsed electromagnetic fields (PEMF)” vs ”placebo”,
there was no significant difference in pain improvement and MMO. ”Active
iontophoresis” (by dexamethasone + lidocaine) showed short-term
improvement in pain and MMO compared with the ”placebo” group, but the
differences were not statistically significant.10
In the ”arthrocentesis” vs ”arthrography only” and ”arthrocentesis” vs
”auriculotemporal nerve block” comparisons, there was no significant
difference in the effects for pain and MMO. ”Arthrocentesis” showed
significant short-term pain improvement compared to ”combination
therapy” (splint plus self-care/self-exercise); there was no significant
difference between interventions for MMO10. Another
review observed that arthrocentesis showed a significant difference in
terms of increased mouth opening and reduced pain level in relation to
the stabilization splint12.
In the “rehabilitation” vs “arthroscopic surgery”and “rehabilitation” vs “arthroplasty” comparisons, there was no
significant difference in the effects for pain and
MMO.8 There was no significant difference in pain
control comparing ”arthroscopic surgery” vs ”self-management”
(self-care/medication/education), ”arthroscopic surgery” vs ”combination
of splint plus exercises” [+ self-care/medication/education +
cognitive behavioral therapy (CBT)] and ”open surgery” vs
”self-management” (self-care/medication/education). Comparing ”open
surgery” vs ”combination of splint plus exercises” (+
self-care/medication/education + CBT), ”open surgery” demonstrated a
significant improvement in pain control in the short term, but not in
the long term.10
There was no “improvement” assessed by the patient,7pain reduction and MMO10 improvement when comparing
”arthrocentesis” vs ”arthroscopy”. Comparing ”open surgery” vs
”arthroscopy”, one of the secondary studies did not report a significant
difference for the ”improvement assessed by the patient” (meta-analysis
through indirect comparisons).7 Meta-analyses from the
other study showed an overall improvement in open surgery and a
significant reduction in long-term pain intensity. Sensitivity analysis
excluding a primary study without imaging diagnosis showed no
significant difference between surgical procedures.10
Figures 2 and 3 show the results of the methodological analysis of the
articles included, according to AMSTAR 2. These data suggest
methodological weaknesses in the studies, added to the limitations of
the primary studies related to heterogeneity. In the overall confidence
rating, all articles included had a critically low confidence level.
According to the OQAQ methodological quality analysis (figure 4), only
three articles had a positive response for all
domains.10-12 In the quality analysis using the CASP,
only two articles showed a positive response for all
domains.10,12 Regarding the assessment of the risk of
bias of the systematic reviews, after answering the focused questions
(Figure 5), none study presented a low risk of bias in all domains of
the instrument (Figure 6).