安慰剂调节正畸牙移动疼痛的随机交叉对照试验

Randomized cross-control trial of placebo in the regulation of orthodontic tooth movement pain

目的探讨安慰剂对正畸牙移动导致的疼痛的治疗效果及作用机制。方法招募60名志愿者作为受试者,随机分为2组。采用维生素B药片作为安慰剂。通过将正畸用分牙橡皮圈放置在左侧下颌第一磨牙的近中侧和远中侧来激发正畸疼痛,安慰剂组在放置分牙橡皮圈0.5 h后服用安慰剂,非安慰剂组只放置分牙橡皮圈。分别在放置分牙橡皮圈前(基线)和放置24 h后,采用视觉模拟评分法(VAS)测量受试者的疼痛水平,采用状态焦虑量表检测焦虑水平,采集唾液样本检测唾液α-淀粉酶(sAA)和皮质醇的分泌水平。经过1个月洗脱期,再次通过放置分牙橡皮圈对两组受试者进行交叉实验。结果与基线相比,放置分牙橡皮圈后安慰剂和非安慰剂组的疼痛水平、焦虑水平均增加;与非安慰剂组相比,安慰剂组的疼痛水平和焦虑水平均明显减少且差异有统计学意义(P<0.05)。放置分牙橡皮圈后,皮质醇和sAA分泌水平均有不同程度的增加,安慰剂组皮质醇分泌水平较非安慰剂组减少且差异有统计学意义(P<0.05),而两组sAA分泌水平的差异无统计学意义(P>0.05)。结论放置分牙橡皮圈能激发正畸疼痛,使疼痛和焦虑水平增加,皮质醇和sAA分泌水平也随之增加。sAA和皮质醇可作为客观的生物学指标用于疼痛强度和焦虑水平的评估。安慰剂可以有效降低由于正畸加力激发的疼痛和焦虑。

Objective This study aims to explore the therapeutic effect of placebo on orthodontic pain and its mechanism.Methods Sixty volunteers were recruited and randomly divided into two groups.Vitamin B tablets were used as placebo.At baseline,orthodontic separators were placed between the left lower molars,and subjects in the placebo group took placebos after half an hour.Only orthodontic separators were placed in the non-placebo group.Pain level(visual analogue scales),anxiety level,and salivary alpha-amylase(sAA)and saliva cortisol of the subjects were measured at baseline and 24 hours after separation.After 1 month of wash-out period,the orthodontic separators were placed between the left lower molars again,and subjects in the two groups were cross-experimented.Results The pain and anxiety levels in the placebo and non-placebo groups increased after placement of orthodontic separators.The pain and anxiety levels in the placebo group were significantly lower than those in the non-placebo group(P<0.05).The levels of cortisol and sAA increased in varying degrees,and the expression of cortisol in the placebo group was lower than that in the non-placebo group(P<0.05).No significant difference was observed in the level of sAA expression between two groups(P>0.05).Conclusion The placement of orthodontic separators can stimulate orthodontic pain.The levels of pain and anxiety increased similar to the levels of cortisol and salivary amylase.Cortisol and sAA can be used as objective biological indicators to evaluate pain intensity and anxiety level,respectively.Placebo can effectively reduce the pain and anxiety caused by orthodontic pain.