De Luca Canto Graziela, Pauletto Patrícia, Stefani Cristine Miron, Gonçalves Thais Marques Simek Vega, Junior Nelson Carvas, Flores-Mir Carlos, Pinto Ana Carolina Pereira Nunes, Trevisani Virginia Fernandes Moça
Brazilian Centre for Evidence-Based Research, Federal University of Santa Catarina, Florianopolis, Brazil.
Department of Dentistry, Federal University of Santa Catarina, Florianopolis, Brazil.
BMC Med Res Methodol. 2025 May 8;25(1):125. doi: 10.1186/s12874-025-02547-9.
To perform a quantitative and qualitative analysis of spin bias in randomized clinical trials (RCTs) focusing on botulinum toxin (BTX-A) for managing bruxism.
This is a meta-epidemiologic study. The protocol was registered on the Open Science Framework.
We included RCTs that evaluated the effectiveness of BTX-A for managing bruxism, associated or not with signs and symptoms of temporomandibular disorders. The outcomes were changes in pain and bruxism events. Spin bias was investigated in abstract and main text. The frequency of spin bias was assessed, and a qualitative analysis was conducted. The study was classified as effective if the outcome analyzed was statistically significant (p-value 0.05) and reached the minimum important difference of 20% and ineffective if the reported outcome was statistically nonsignificant or the study did not report the p-value or the results did not reach the minimum important difference of 20%.
An overall frequency of 59.4% spin bias was identified in eight included RCTs. The conclusion in the main text (87.5%) was the section with the highest frequency of spin bias. In the qualitative analysis, the most common strategies identified were inadequate extrapolation to a large population (30.61%), inadequate implication for clinical practice (20.41%), and misleading reporting (12.25%).
There is a high frequency of spin bias in RCTs that evaluated BTX-A for bruxism management. Close to 90% of the selected RCTs presented spin bias in the main text's conclusion. The most common spin was the inadequate extrapolation of the results.
Applying BTX into the temporalis did not reduce muscle activity and the results for masseter injections remain controversial. It seems that BTX-A injections can reduce pain from two weeks to one year. It is not possible to have certainty about the efficacy and safety of using BTX-A to reduce pain and bruxism events.
对聚焦于肉毒杆菌毒素（BTX - A）治疗磨牙症的随机临床试验（RCT）中的结果偏倚进行定量和定性分析。
这是一项元流行病学研究。该方案已在开放科学框架上注册。
我们纳入了评估BTX - A治疗磨牙症有效性的随机对照试验，无论其是否伴有颞下颌关节紊乱的体征和症状。结局指标为疼痛和磨牙症事件的变化。在摘要和正文部分对结果偏倚进行调查。评估结果偏倚的频率，并进行定性分析。如果分析的结局具有统计学显著性（p值<0.05）且达到最小重要差异20%，则该研究被分类为有效；如果报告的结局无统计学显著性，或研究未报告p值，或结果未达到最小重要差异20%，则该研究被分类为无效。
在纳入的8项随机对照试验中，总体结果偏倚频率为59.4%。正文部分的结论（87.5%）是结果偏倚频率最高的部分。在定性分析中，确定的最常见策略是对大量人群的外推不足（30.61%）、对临床实践的意义不足（20.41%）和误导性报告（12.25%）。
在评估BTX - A治疗磨牙症的随机对照试验中，结果偏倚的频率较高。近90%的所选随机对照试验在正文结论中存在结果偏倚。最常见的结果偏倚是结果的外推不足。
将BTX注射到颞肌中并不能降低肌肉活动，咬肌注射的结果仍存在争议。似乎BTX - A注射可在两周至一年内减轻疼痛。使用BTX - A减轻疼痛和磨牙症事件的疗效和安全性尚无法确定。
