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.

中文翻译：

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在治疗疼痛性颞下颌关节疾病方面，咬合稳定器具的治疗效果是否不仅仅是安慰剂效应？随机临床试验的网络荟萃分析

问题陈述

咬合装置，特别是稳定装置，已普遍用于治疗疼痛性颞下颌疾病 (TMD)。然而，这些装置的作用机制仍不清楚，包括安慰剂效应在疼痛管理中的作用。

目的

该网络荟萃分析的目的是确定稳定器具在治疗疼痛性 TMD 方面的有效性程度仅来自安慰剂效应还是主要来自实际效应。

材料与方法

进行了一项电子搜索，以确定截至 2020 年 4 月发表的随机临床试验 (RCT)，比较了稳定装置在疼痛性颞下颌疾病患者中的疗效，以及非咬合装置（主动安慰剂）和未治疗对照（被动安慰剂）。结果变量包括随访时的疼痛强度、报告疼痛改善的参与者比例以及需要治疗的人数。证据质量根据 Cochrane 偏倚风险评估工具进行评级。使用STATA软件程序通过频率论网络荟萃分析使用平均差异进行分析。

结果

与其他组相比，稳定器治疗显示疼痛强度显着降低；但是，与非咬合装置相比，使用稳定装置的后续疼痛强度较低，但没有统计学意义。然而，与使用非闭塞器具治疗或未经治疗的参与者相比，使用稳定器具治疗后疼痛改善的参与者人数明显更多。

结论

该网络荟萃分析显示，使用稳定装置或非闭塞装置（活性安慰剂）治疗疼痛性 TMD 之间在随访时报告的疼痛强度没有显着差异。然而，报告发现疼痛减轻的治疗满意度显着差异，并且需要使用稳定器具治疗的人数显着减少。患者报告的治疗满意度可能包括更多领域，而不仅仅是疼痛强度，例如身体机能和社会心理因素的改善，值得进一步调查。作者得出结论，稳定器具的治疗效果超出了安慰剂效果。