Abstract：
OBJECTIVE: This systematic review aims to summarize and synthesize the evidence that investigates the secondary effects of the application of botulinum toxin (BT) into the masticatory muscles and its effects on bone density.
METHODS: Database searches were conducted until March 19th, 2024. The quality of the studies was assessed by the Cochrane tool risk of bias for the randomized controlled trials and the ROBINS-I tool for non-randomized studies. The Cochrane Grading of Recommendations Assessment Development and Evaluation (GRADE) was used to evaluate the confidence in the overall evidence.
RESULTS: Five studies looking at the effects of botulinum toxin on bone density and resorption when applied to masticatory muscles were found. No significant changes were observed in most of the studies when looking at the effects of botulinum toxin on mandibular condyle volume, density, mandibular angle thickness, and coronoid process volume. The only finding that was statistically and clinically relevant was the difference between patients who received a double application of BT when compared with patients who received a single application (SMD: -0.99 [95%CI: -1.94,-0.05]) on the volume of the mandibular angle.
CONCLUSIONS: There is no clear pattern on whether the application of botulinum toxin is associated with bone resorption or not. Although some studies show statistical significance of the findings, the magnitude of the changes in bone density and their clinical significance are not completely clear.
CONCLUSIONS: To understand the effectiveness of the use of botulinum toxin into the masticatory muscles and its possible secondary adverse effects on the density of the mandible.
METHODS: Database searches were conducted until March 19th, 2024. The quality of the studies was assessed by the Cochrane tool risk of bias for the randomized controlled trials and the ROBINS-I tool for non-randomized studies. The Cochrane Grading of Recommendations Assessment Development and Evaluation (GRADE) was used to evaluate the confidence in the overall evidence.
RESULTS: Five studies looking at the effects of botulinum toxin on bone density and resorption when applied to masticatory muscles were found. No significant changes were observed in most of the studies when looking at the effects of botulinum toxin on mandibular condyle volume, density, mandibular angle thickness, and coronoid process volume. The only finding that was statistically and clinically relevant was the difference between patients who received a double application of BT when compared with patients who received a single application (SMD: -0.99 [95%CI: -1.94,-0.05]) on the volume of the mandibular angle.
CONCLUSIONS: There is no clear pattern on whether the application of botulinum toxin is associated with bone resorption or not. Although some studies show statistical significance of the findings, the magnitude of the changes in bone density and their clinical significance are not completely clear.
CONCLUSIONS: To understand the effectiveness of the use of botulinum toxin into the masticatory muscles and its possible secondary adverse effects on the density of the mandible.
摘要：
目的：本系统综述旨在总结和综合研究肉毒杆菌毒素（BT）应用于咀嚼肌的继发性作用及其对骨密度的影响的证据。
方法：数据库搜索一直进行到3月19日，2024.通过Cochrane工具对随机对照试验的偏倚风险和ROBINS-I工具对非随机研究进行评估。Cochrane建议评估开发和评估等级（GRADE）用于评估总体证据的置信度。
结果：发现了五项关于肉毒杆菌毒素应用于咀嚼肌时对骨密度和再吸收的影响的研究。在观察肉毒杆菌毒素对下颌髁突体积的影响时，大多数研究均未观察到显着变化，密度,下颌角厚度，和冠状突体积。唯一具有统计学和临床相关性的发现是接受两次BT的患者与接受一次BT的患者之间的差异（SMD：-0.99[95CI：-1.94，-0.05]）下颌角。
结论：关于肉毒杆菌毒素的应用是否与骨吸收有关，尚无明确的模式。尽管一些研究显示了这些发现的统计学意义，骨密度变化的幅度及其临床意义尚不完全清楚。
结论：为了了解将肉毒杆菌毒素用于咀嚼肌的有效性及其对下颌骨密度的可能的继发性不利影响。
方法：数据库搜索一直进行到3月19日，2024.通过Cochrane工具对随机对照试验的偏倚风险和ROBINS-I工具对非随机研究进行评估。Cochrane建议评估开发和评估等级（GRADE）用于评估总体证据的置信度。
结果：发现了五项关于肉毒杆菌毒素应用于咀嚼肌时对骨密度和再吸收的影响的研究。在观察肉毒杆菌毒素对下颌髁突体积的影响时，大多数研究均未观察到显着变化，密度,下颌角厚度，和冠状突体积。唯一具有统计学和临床相关性的发现是接受两次BT的患者与接受一次BT的患者之间的差异（SMD：-0.99[95CI：-1.94，-0.05]）下颌角。
结论：关于肉毒杆菌毒素的应用是否与骨吸收有关，尚无明确的模式。尽管一些研究显示了这些发现的统计学意义，骨密度变化的幅度及其临床意义尚不完全清楚。
结论：为了了解将肉毒杆菌毒素用于咀嚼肌的有效性及其对下颌骨密度的可能的继发性不利影响。
