Discussion
This overview summarized data and key results from five systematic
reviews that investigated the effects of different DDwoR treatments and
assessed the quality of evidence from these reviews. The analysis of
general data revealed heterogeneity between studies. Despite the
significant number of primary studies on the subject, the significant
variation in pairwise comparisons within each study compromises
evidence-based clinical/surgical decision-making for the treatment of
DDwoR. Different outcome evaluation criteria and follow-up times were
also observed. These characteristics also compromised the grouping of
studies for meta-analyses in systematic reviews.
Among the reviews that performed meta-analyses,7-10,12one included only one RCT9 and three included two to
four RCTs.8,10,12 In a third systematic review, 15
studies were considered in the meta-analysis,7 based
on indirect comparisons, including comparison between prospective
uncontrolled studies and RCTs. These authors constructed a different
artificial, untreated control group, which represents a bias and
compromises the degree of confidence of the results, since the
comparative analyzes were not based on real samples and did not consider
eligibility criteria, random allocation, collection and blind analysis
of the data.
Despite the number of primary studies on the subject, this overview
revealed a significant variation in comparisons related to the treatment
of DDwoR in RCTs. Comparison between different non-invasive
modalities,8-10 non-invasive versus minimally
invasive,10,12 non-invasive versus
invasive,8-10 minimally invasive versus
invasive7,10 and comparison between invasive
modalities7-10 were observed.
The systematic reviews included primarily compared the effects of
non-invasive treatments for DDwoR. This can be explained by the fact
that this modality is considered, by consensus, as the first therapeutic
option for DDwoR. In addition, the significant number of non-invasive
options applied alone or in combination in the treatment of DDwoR also
contributes to a greater number of publications and favors the carrying
out of secondary studies on the subject.
The signs and symptoms associated with DI are caused by the loss of
intra-articular tissue structure and function, compromising the
biomechanics of the biomechanical temporomandibular joint. The cause of
this tissue failure is most often joint overload, leading to tissue
failure and an inflammatory/degenerative arthropathy of the
temporomandibular joint.20
It is not possible to state which is the best non-invasive treatment
method, as in most reported results no significant difference was
detected in pain control and improvement in MMO between groups. This
finding may be related to the self-limited natural course of DDwoR.
Significant improvement in clinical symptoms of closed lock is expected
in 75 % of patients over a 2.5-year follow-up. The reduction in pain
and mouth opening restriction is probably associated with the active
adaptation to the new structural situation of the
TMJ.20,21 Even so, the therapeutic approach to DDwoR
is necessary due to the expected benefits of pain and functional
limitations, in addition to preventing osteoarthritis as an evolution of
the internal TMJ disorder. The persistence of these clinical symptoms
and the evolution of joint TMD lead to the need for TMJ invasive
therapeutic approaches.
In this context, the minimally invasive modalities, represented by
arthrocentesis, represent the first step in the treatment of ID, after
the failure of the non-invasive approach. This technique had mild and
pain-restricted benefits, only in the short term, compared to the
non-invasive combined treatment. Despite limitations for clinical
decision-making associated with heterogeneity between studies, the data
summarized in this overview suggest a small benefit of arthrocentesis in
the treatment of DDwoR, restricted to clinical symptoms and only in the
short term, compared to non-invasive therapeutic modalities.
Arthroscopic surgery and arthroplasty did not show significant
differences in pain control and MMO compared to non-invasive
modalities,8-10 and arthrocentesis and arthroscopy did
not differ for improvement assessed by the patient, pain reduction and
MMO.7,10 Open surgery showed short-term improvement in
pain control compared to non-invasive treatment, significant overall
improvement and long-term improvement in pain intensity, compared to
arthroscopy.10
The optimal treatment for DDwoR should not be considered universal
protocol, but a personalized approach. Each patient must be assessed and
treated individually considering the severity of symptoms and functional
limitations associated with TMD, prioritizing the non-invasive treatment
model, followed by minimally invasive and invasive/open surgery
modalities. Bronstein and Merrill21 reported higher
success rates for arthroscopic treatment of ID in early stages than in
advanced stages. Zhang et al.22 reported that
arthroscopic disc repositioning was not appropriate for Wilkes stage IV
or V, suggesting a limitation of the technique for more complex cases.
Successive treatment attempts by different therapeutic modalities, in a
gradual hierarchical sequence of complexity/invasiveness, should
represent delay in the remission of clinical signs and symptoms of TMD
associated with DDwoR and greater morbidity in more complex/severe
cases. However, invasive procedures, such as open surgery, must be
carefully indicated considering the possible
pitfalls.23
Despite the limitations of this study and the impossibility of
establishing the most effective evidence-based treatment for DDwoR, all
treatments benefit patients and had slightly different effects from each
other, except for open surgery which resulted in overall improvement and
a significant reduction in long-term pain intensity. Invasive procedures
should not be the first choice in the treatment of DDwoR, however, the
literature suggests that open surgery should be considered a possibility
for the most severe cases.