A new method to orthodontically correct dental occlusal plane canting: wave-shaped arch

目的:提出一种利用牙弓左右交互支抗矫治牙性(牙合)平面倾斜的新方法,即第二序列的波浪形弓,并检验其临床疗效.方法:选取恒牙期错(牙合)畸形患者,无明显颌骨不对称畸形,常规检查设计,安装MBT矫治器,用序列弓丝排齐整平牙列后,正面观察患者颜面评价上下前牙(牙合)平面是否倾斜,如患者本人和两名正畸医生都认为存在(牙合)平面倾斜即入选.共37名患者,男性10人,女性27人,平均年龄(21.9±5.2)岁.在横截面0.46 mm×0.56 mm的不锈钢方丝上弯制第二序列摇椅形曲,以面部中线为基准左右侧摇椅形曲的方向相反,曲度一致,以正常的前牙(牙合)平面做参照,牙齿过长侧弯制朝向牙龈的弧形,牙齿过低侧弯制朝向(牙合)面的弧形,矫治弓丝在第二序列上呈波浪形.应用波浪形弓矫治(牙合)平面倾斜,在矫治前后拍摄小开口位患者的正面像,同时使用口唇开张器牵拉口角显示(牙合)平面,在Image J1.48v图像处理软件中测量图像上左右侧尖牙托槽近中边缘槽沟中点连线(代表前牙(牙合)平面)与瞳孔连线的夹角,在SPSS 10.0统计软件中使用配对Wilcoxon检验比较治疗前后的数值.结果:波浪形弓可以有效矫治前牙(牙合)平面倾斜,疗程3～ 10个月,平均(5.5±1.7)个月.治疗前左右侧尖牙托槽近中边缘槽沟中点连线与瞳孔连线的夹角中位数为4.01°,最大值6.12°,最小值2.90°;治疗后中位数为1.87°,最大值2.57°,最小值-0.17°;治疗后角度减小中位数为2.21°,最大值4.15°,最小值1.08°,配对Wilcoxon检验P=0.000.结论:波浪形弓可以独立或与其他矫治方法联合使用,利用左右侧交互支抗可有效矫治前牙(牙合)平面倾斜,在临床上有一定的应用价值.Objective:To introduce a technique of second order wave-shaped arch wire to orthodontically treat dental occlusal plane canting (DOPC) with left-right interactive anchorage,and to test its clinical efficacy.Methods:Among the permanent dentition malocclusion patients who showed no obvious facial asymmetry,we screened for patients who showed anterior occlusal plane canting (AOPC) after routine orthodontic examination,treatment planning,MBT fixed appliance installation and serial arch wires alignment.Each patient had been clinically appraised in frontal view by 2 orthodontists and the patient him/herself;if all 3 agreed that the AOPC was obvious,the patient was included.By this means,we ineluded 37 patients,including 10 males and 27 females;the average age was (21.9 ± 5.2) years.To correct AOPC,opposite direction equal curvature second order rocking-chair curve was bent on each side of 0.46 mm × 0.56 mm stainless steel edgewise wire.With reference to normal occlusal plane,a curve toward the occlusal surface was made to extrude under-erupted teeth on one side while a curve toward the gingiva was made to intrude over-erupted teeth on the other side,so that the arch wire was made into a wave shape in vertical dimension.Before and after application of wave-shaped arch wire,frontal facial photographs were taken when the patient's mouth was open slightly with lips retracted to show anterior occlusal plane (AOP) clearly.An AOP was constructed by connecting the center of the slot in the medial edge of canine bracket on each side in the photograph.The angles between the bipupillary plane (BPP)and the constructed AOP were measured in ImageJ1.48v software and the angle differences before and af ter treatment were compared with paired Wilcoxon test in SPSS 10.0 software.Results:The wave-shaped arch could correct AOPC effectively in 3 to 10 months time with an average of 5.5 ± 1.7 months;the angles between AOP and BBP before treatment ranged from 2.90° to 6.12° with a median of 4.01°;after treatment the angles were from-0.17° to 2.57° with a median of 1.87°,the decrease of the angles between AOP and BBP after treatment ranged from 1.08° to 4.15° with a median of 2.21 Paired Wilcoxon test P was 0.000.Conclusion:The wave-shaped arch can be used independently or in combination with other treatment methods,which can take advantage of left and right interactive anchorage to correct AOPC effectively,so it has certain application value in clinical practice.北京大学第三医院回国人员启动基金(Y73512-01)资助 Supported by the Peking University Third Hospital Initial Scientific Research Fund for Returned Oversea Scholars中国科学引文数据库(CSCD)1176-1804