正畸治疗过程中前牙牙髓活力与疼痛变化的观察与分析

The changes of anterior teeth pulp vitality and pain during orthodontic treatment

目的 探讨正畸治疗过程中前牙牙髓活力与患者疼痛值的变化规律.方法 选取采用唇侧固定矫治的24名青少年患者作为研究对象,使用数字式全自动无痛牙髓活力测试仪定期检测受试者前牙区牙髓组织对外界电刺激的反应阈值（EPT）,并采用视觉模拟评分工具（VAS）评价正畸治疗过程中疼痛反应的变化情况.检测的时间包括13个时间点：0表示正畸治疗前,A1～A3、B1～B3、C1～C3、D1～D3分别表示排齐整平阶段常用4种不同尺寸镍钛弓丝（0.012英寸、0.016英寸、0.016×0.022英寸、0.018×0.025英寸）的加力过程,每根弓丝检测三个时间点（1-更换弓丝后即刻、2-更换弓丝72小时后,3-拆卸弓丝前即刻）.结果 正畸加力开始后,A1～D3的EPT均值高于治疗前O的EPT均值（37.29±9.01）,具有统计学差异（P＜0.05）.放置第一根弓丝时,前牙在A1的EPT均值大于O的EPT均值（P＜0.05）;而顺序更换弓丝时,A3与B1、B3与C1、C3与D1之间的EPT均值均无统计学差异（P＞0.05）.对每根弓丝矫治阶段内的VAS疼痛值变化情况进行分析,A2、B2、C2、D2时间点的疼痛值均大于该时间段内其余两个时间点的疼痛值,并且A2时间点疼痛值大于B2、C2、D2时间点疼痛值（P＜0.05）.结论 正畸排齐整平阶段前牙牙髓组织对外界电刺激呈现略迟钝状态.首次粘接托槽放置第一根弓丝后可出现牙髓活力明显迟钝,而之后顺序更换弓丝不会引起牙髓活力的显著改变.疼痛峰值出现在首次戴用矫治器后的第3天,并呈现一定周期性变化的特征,表现为每次换丝后第三大左右疼痛增加,而后逐渐缓解.

Objective To explore the changes of anterior teeth pulp vitality and pain during orthodontic treatment.Methods 24 adolescent patients seeking for fixed orthodontic treatment were selected.The pulp vitalities of anterior teeth were periodically evaluated using digital electric pulp tester to test the responsive threshold to electric stimuli （EPT）.The severities of pain during orthodontic treatment were evaluated using a visual analog scale （VAS）.There were 13 evaluation time points：O represented the baseline before treatment;A1-A3,B1-B3,C1-C3 and D1-D3 represented four different treatment stages using four types of nickel-titanium archwires （0.012 inch,0.016 inch,0.016×0.022 inch and 0.018＆215;0.025 inch） respectively.Each stage included three time points：1-immediately after archwire engagement,2-72hrs after engagement,and 3-immediately before archwire removal.Results During orthodontic treatment,the EPT mean values at time points A1-D3 were significantly higher than that at pre-treatment time point O （P〈0.05）.In the sequential archwire removal and engagement process,no significant difference was found of EPT changes when comparing A3/B1,B3/C1 and C3/D1 （P〉0.05）.Regarding the VAS scores in each archwire stage,the scores at A2,B2,C2 and D2 were significantly higher than the other two time points （1 and 3）within the same stage.Besides,the score at A2 was significantly higher than that at B2,C2 and D2 （P〈0.05）.Conclusions The pulp of anterior teeth was less sensitive to electric stimulus during orthodontic alignment and leveling process.The pulp vitality of anterior teeth significantly decreased after the engagement of the first archwire;however,no significant change of pulp vitality was found during the subsequent sequential removal and engagement of archwires.The VAS pain reached the peak at three days after first archwire engagement and fluctuated periodically afterwards;it increased at the third day of each replacement of archwire and then relieved gradually.