Is the therapeutic effect of occlusal stabilization appliances more than just placebo effect in the management of painful temporomandibular disorders? A network meta-analysis of randomized clinical trials

The Journal of Prosthetic Dentistry

Available online 16 October 2020

The Journal of Prosthetic Dentistry

Abstract

Statement of problem

Occlusal devices, particularly the stabilization appliances, have been commonly used as treatment for painful temporomandibular disorders (TMDs). However, the mechanisms of action of these devices are still unclear, including the role of the placebo effect in the pain management.

Purpose

The purpose of this network meta-analysis was to identify to what extent the degree of efficacy of stabilization appliances in the management of painful TMDs arises from the placebo effect only or whether it arises chiefly from an actual effect.

Material and methods

An electronic search was undertaken to identify randomized clinical trials (RCTs) published up to April 2020, comparing the efficacy of the stabilization appliances in patients with painful temporomandibular disorders, with nonoccluding appliances (active placebo), and untreated controls (passive placebo). Outcome variables were pain intensity at follow-ups, the proportion of participants reporting pain improvement, and the number needed to treat. The quality of evidence was rated as per the Cochrane tool for assessing risk of bias. Mean difference was used to analyze via frequentist network meta-analysis by using the STATA software program.

Results

Treatment with stabilization appliances showed a significant reduction in pain intensity when compared with the other groups; but, the lower pain intensity at follow-ups in favor of stabilization appliances when compared with nonoccluding appliances was not statistically significant. However, a significantly higher number of participants reported pain improvement after treatment with stabilization appliances when compared with those treated with nonoccluding appliances or untreated participants.

Conclusions

This network meta-analysis showed no significant difference in reported pain intensity at follow-ups between the treatment of painful TMDs with stabilization appliances or nonoccluding appliances (active placebo). However, a significant difference in participants reporting treatment satisfaction with reduced pain, and a significantly lower number needed to treat in favor of stabilization appliances were found. Patient-reported treatment satisfaction probably included more domains than just pain intensity, such as improvements in physical functioning and psychosocial factors, and deserves further investigation. The authors concluded that stabilization appliances treatment efficacy is beyond the placebo effect.

Clinical Implications

Stabilization appliances seem to have a treatment efficacy beyond the placebo effect and can be suggested as one of the initial treatment approaches for patients with painful temporomandibular disorders. However, the evaluation of the effect of the treatment must include more domains than just change the pain intensity. Based on the outcome of this systematic review as well as that of other studies, pain intensity is not an appropriate treatment outcome measure by itself but should be used in combination with other domains such as physical functioning.


 

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