引用本文
王旭, 章晶晶, 原福松, 王郁, 李成皓, JuhaEerikVarrela, 岳江, 葛立宏. 萌出诱导矫治器治疗儿童个别前牙反牙合的三维数字化分析. 北京大学学报(医学版), 2018,50(3): 532-537
WANG Xu, ZHANG Jing-jing, YUAN Fu-song, WANG Yu, LI Cheng-hao, Juha Eerik Varrela, YUE Jiang, GE Li-hong. Three-dimensional analysis of the early correction of anterior crossbite using eruption guidance appliance. Journal of Peking University(Health Sciences), 2018,50(3): 532-537.  
Doi: 10.3969/j.issn.1671-167X.2018.03.023
Permissions
Copyright©2018, 北京大学
《北京大学学报(医学版)》编辑部 所有
萌出诱导矫治器治疗儿童个别前牙反牙合的三维数字化分析
王旭1, 章晶晶1, 原福松1, 王郁1, 李成皓2, JuhaEerikVarrela3, 岳江4, 葛立宏1,Δ
1. 北京大学口腔医学院·口腔医院, 儿童口腔科,国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室 卫生部口腔医学计算机应用工程技术研究中心, 北京 100081;
2. 同济大学口腔医学院及附属口腔医院儿童口腔科,上海 200072
3. Institute of Dentistry, University of Turku, Turku 20014, Finland
4. 青苗儿童口腔研究院,北京 100085
收稿日期: 2017-10-08
资助项目: 北京大学口腔医学院院内博士后种子基金(YS0203)资助
摘要

目的:探讨萌出诱导矫治器治疗混合牙列期儿童个别前牙反牙合的临床效果。方法:选择10例存在个别前牙反牙合的混合牙列期患儿,共计12颗前牙,用藻酸盐采取上、下颌印模并灌制硬石膏模型,送做萌出诱导矫治器,应用该矫治器进行治疗。通过SmartOptics Activity 880牙颌模型扫描仪,获取患儿治疗前、后的三维牙颌数字模型,应用逆向工程软件Geomagic Studio 2012构建三维重叠模型,利用Imageware 13.2软件测量反牙合的上、下切牙在三维方向上的移动变化,对矫治前、后的覆牙合、覆盖进行测量。应用铜丝测量法直接测量上、下颌牙弓弧长,相应的牙冠宽度(未萌出的恒牙按照X线片法预测牙冠宽度)减去牙弓弧长计算上、下颌牙弓的拥挤程度。使用SPSS17.0 软件对同一患儿的术前、术后测量值进行统计学分析,首先对测量指标的术后改变量进行正态性检验,发现符合正态分布,然后采用配对样本 t检验,双侧检验,显著性水平为0.05。结果:疗程为(5.6±2.7)个月,矫治过程中,上、下切牙在三维位移上均主要表现为唇倾( P<0.001、 P=0.025)。经过萌出诱导矫治器的治疗,覆牙合减少了(1.01±0.9) mm ( t=-3.531, P=0.006), 差异具有统计学意义,而术前、术后覆盖的差异不具有统计学意义( t=0.771, P=0.460)。上颌拥挤度减少了(1.9±0.99) mm ( t=-6.042, P<0.001),下颌拥挤度减少了(1.9±0.74) mm ( t=-8.143, P<0.001),差异均具有统计学意义。结论:萌出诱导矫治器可以治疗混合牙列期个别前牙反牙合,同时有建立正常覆牙合、覆盖,排齐牙齿的作用。

关键词: 混合牙列期; 个别前牙反牙合; 萌出诱导矫治器; 三维测量分析
中图分类号:R788 文献标志码:A 文章编号:1671-167X(2018)03-0532-06
Three-dimensional analysis of the early correction of anterior crossbite using eruption guidance appliance
WANG Xu1, ZHANG Jing-jing1, YUAN Fu-song1, WANG Yu1, LI Cheng-hao2, Juha Eerik Varrela3, YUE Jiang4, GE Li-hong1,Δ
1. Department of Pediatric Dentistry,Peking University School & Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology & Research Center of Engineering and Technology for Digital of Ministry of Health, Beijing 100081,China;
2. Department of Pediatric Dentistry,The Affiliated Stomatology Hospital of Tongji University, Shanghai 200072, China
3. Institute of Dentistry,University of Turku,Turku 20014,Finland
4. Institute of Children’s Oral Health of Qingmiao,Beijing 100085, China;
Δ Corresponding author’s e-mail, gelh0919@126.com
Fund:Supported by the Postdoctoral Seed Fund of Peking University School & Hospital of Stomatology (YS0203)
Abstract

Objective:To investigate the clinical effect of eruption guidance appliance in the treatment of anterior cross bite in mixed-dentition children.Methods:In the study,10 mixed-dentition children with anterior cross bite,totally 12 incisors, were selected. Alginate was used to take upper and lower dentition impression and make a hard plaster model,which served as the eruption guidance appliance for treatment. The pre- and post-operative dental casts were digitized with SmartOptics Activity 880 scanner,and the three-dimensional overlapping models were obtained by reverse engineering software,Geomagic Studio 2012,then the three-dimensional movements of the upper and lower incisors were analyzed using Imageware 13.2 software. The overbite and overjet were analyzed using the same methods. Measurement with copper wire was used to analyze the upper and lower arch length. Space analysis was the result by the sum of crown width minus the arch length. The crown width of unerupted permanent teeth was accor-ding to X-ray method to predict. The SPSS 17.0 software was used to analyze the pre- and post-operative measurements of the same child. The normality test of the measured data showed that it conformed to the normal distribution. Therefore,the t test and double side test were used,and the significance level was 0.05.Results:The course of treatment was (5.6±2.7) months. During orthodontic treatment, the upper incisors moved mainly labially( P<0.001)in three-dimensional displacement,and the lower incisors moved mainly the same direction( P=0.025). During the treatment of eruption guidance appliance,the average overbite decreased (1.01±0.9) mm( t=-3.531, P=0.006),and the difference was statistically significant. There was no statistically significant difference between the pre- and post-operative average overjet( t=0.771, P=0.460). The severity of crowding in upper arch decreased (1.9±0.99) mm ( t=-6.042, P<0.001),and that in lower arch decreased (1.9±0.74) mm ( t=-8.143, P<0.001), both of the differences were statistically significant.Conclusion:The anterior cross bite in mixed dentition could be corrected by eruption guidance appliance,and at the same time,the normal overjet and overbite were established,and the teeth were aligned.

Key words: Mixed dentition; Anterior crossbite; Eruption guidance appliance; Three-dimensional analysis

前牙反牙合指上颌前牙位于下颌前牙的舌侧, 通常累及一个或多个切牙, 在不同人群、种族中其患病率为2.2%~11.9%[1]。个别前牙反牙合不仅影响美观, 而且可能会对下切牙造成咬合创伤, 导致下切牙的牙龈退缩、牙槽骨吸收、牙齿松动[2], 颞下颌关节功能障碍[3], 影响上下颌骨的前部发育[1], 同时对患儿的身心健康造成影响[4]。目前患儿及家长对美观的要求日益提高, 隐形矫治的需求越来越大。

萌出诱导矫治器是一种混合牙列期使用的覆盖式矫治装置, 已于20世纪90年代在欧洲国家应用, 在儿童早期牙齿排齐及Ⅰ 类颌骨关系的建立上取得了良好的矫治效果[5, 6]。它根据儿童牙弓大小个体化制作, 包括预成的弓形及理想的上、下颌位置关系, 弓形中牙齿形态的凹槽有利于牙齿的排齐。矫治器富有弹性, 戴用时儿童需将上下牙咬入凹槽。目前未见针对萌出诱导矫治器对混合牙列期个别前牙反牙合治疗的疗效评价, 因此本研究尝试使用萌出诱导矫治器早期治疗儿童个别前牙反牙合, 并改善咬合关系和牙弓形态, 应用SmartOptics Activity 880牙颌模型扫描仪获取患儿治疗前、后具有咬合关系的上、下颌数字牙颌模型, 并应用三维逆向工程软件Geomagic Studio 2012 和Imageware 13.2对矫治效果进行综合评估, 探究萌出诱导矫治器对混合牙列期个别前牙反牙合的矫治效果。

1 资料与方法
1.1 研究对象

本研究选取2015年1月至2016年9月在北京大学口腔医院儿童口腔科就诊的患儿10例, 其中男4例, 女6例, 最大年龄10岁, 最小年龄6岁9个月, 平均年龄8岁6个月, 共计反牙合前牙12颗。纳入标准:(1)混合牙列早期, 且第一恒磨牙已经建牙合, (2)头影测量结果为骨性Ⅰ 类, 均角, (3)磨牙关系为安氏Ⅰ 类, (4)上、下切牙轻度拥挤, (5)无口腔不良习惯, (6)上切牙无外伤史, (7)患儿配合度好, (8)患儿家长知情同意。排除标准:(1)头影测量结果显示为骨性Ⅱ 类或Ⅲ 类, (2)磨牙关系为安氏Ⅱ 类或Ⅲ 类, (3)上、下切牙中重度拥挤, (4)有吮指、口呼吸等口腔不良习惯, (5)患儿不能配合佩戴矫治器。本研究通过北京大学口腔医院伦理委员会审查(PKUSSIRB-201412014)。

1.2 萌出诱导矫治器

对选取的患儿用藻酸盐采取上、下颌印模并灌制硬石膏模型, 送做萌出诱导矫治器(YZB/FIN7873-2014, LM-Instruments Oy公司, 芬兰), 具体佩戴萌出诱导矫治器要求如下:每日白天戴用1 h, 每晚睡眠时戴用, 总体佩戴时间≥ 8 h/d。所有患儿均达到佩戴要求(图1)。

图1 萌出诱导矫治器的口外观(A)及在口内的戴用(B)Figure 1 Appearance of eruption guidance appliance outside (A) and inside (B) the mouth

1.3 三维数字化牙颌模型的重叠与测量

分别在患儿治疗前和治疗后用藻酸盐采取上、下颌印模并灌制硬石膏模型, 应用SmartOptics Acti-vity 880牙颌模型扫描仪获取具有咬合关系的上、下颌数字三维牙颌模型, 输出格式为标准模板库(Standard Template Library, STL)的三维数据(图2)。

图2 三维数字化牙颌模型的重叠与测量Figure 2 Overlapping and measurements of three-dimensional digital dental models
A, three-dimensional movements of post-operative teeth(red); B, measurements of overbite and overjet before treatment; C, measurements of overbite and overjet after treatment.

1.3.1 反牙合切牙的三维位移量测定 在Geomagic Studio 2012逆向工程软件中导入STL数据, 以上颌模型腭部为基准, 对治疗前、后的咬合模型进行配准, 获得三维重叠模型。将配准后的模型数据导入Imageware 13.2软件中, 以矫治后上颌模型左、右第一恒磨牙近中颊尖点连线为水平线(X轴), 通过左、右中切牙近中切角中点, 做垂直于水平线的矢状线(Z轴), 通过水平线中点(坐标原点)做垂直于由水平线、矢状线构成的平面的垂线(Y轴), 从而构建出上颌模型的局部坐标系。分别测量反牙合的上、下切牙的切缘中点治疗前、后在此坐标系中的坐标, 由此得出上、下颌切牙在水平向、垂直向及矢状向上的位移量。

1.3.2 覆牙合测量 通过左、右上中切牙的近中切角中点, 以及双侧上颌第一恒磨牙近中颊尖点做基准平面, 定义左、右下中切牙近中切角中点到基准平面的距离为覆牙合大小。利用Imageware 13.2软件分别测量治疗前及治疗后模型的覆牙合大小。

1.3.3 覆盖测量 Imageware 13.2软件自动提取下颌三维模型与基准平面的弧形交线, 通过双侧上中切牙近中切角中点测量基准平面与下中切牙唇面弧线的最近距离, 定义为覆盖大小。分别测量治疗前及治疗后模型的覆盖大小。

1.4 上、下牙弓拥挤度的测量

应用铜丝测量法直接测量上、下牙弓弧长, 即用一根直径0.5 mm左右的铜丝沿着前牙切缘、乳尖牙牙尖、乳磨牙颊尖及第一恒磨牙邻面接触点按着现有牙弓完成弓形, 不包括明显错位的牙齿。牙冠总宽度与现有牙弓弧长的差值即为牙弓的拥挤程度。对于未萌恒牙牙冠的宽度用X线测量法进行测量, 用以下公式进行计算:X=X’ Y/Y’ (X为未萌恒牙的实际宽度; X’ 为曲面体层片上测得的未萌牙胚的宽度; Y为模型上乳牙的实际宽度; Y’ 为曲面体层片上测得的宽度)[7]。

1.5 统计学分析

对所测同一患儿的术前、术后数据利用SPSS 17.0软件进行分析比较。数据描述为均数± 标准差, 对测量牙齿的术后三维位移量, 同一患儿术后覆牙合、覆盖和拥挤度的改变量进行正态性检验, 符合正态分布的数据进行配对样本t检验, 双侧检验, 以P< 0.05为差异具有统计学意义。

2 结果
2.1 个别前牙反牙合矫治效果的临床观察

10例患儿共12颗上颌切牙纳入研究, 在应用萌出诱导矫治器治疗后均得到矫正, 最短疗程1个月, 最长疗程9个月, 平均疗程5.6个月; 其中1例患儿因矫治器咬坏, 1例因矫治器丢失更换矫治器, 在1周内均获得新矫治器, 继续佩戴, 其余8例均未更换矫治器。

2.2 牙齿的三维变化

完成治疗的10例患儿12颗上颌切牙及其对应的下颌切牙的三维位置位移量如表1所示, 上、下颌切牙均主要表现为唇倾。

表1 混合牙列期个别前牙反牙合儿童经萌出诱导矫治器治疗后的上、下切牙三维位置改变量(n=12) Table 1 Three-dimensional displacement amount of upper and lower incisors in mixed-dentition children with anterior crossbite after using eruption guidance appliance (n=12)
2.3 覆牙合、覆盖的变化

如表2所示, 经过萌出诱导矫治器治疗, 覆牙合的变化差异具有统计学意义, 而覆盖的变化差异无统计学意义。

表2 混合牙列期个别前牙反牙合儿童经萌出诱导矫治器治疗后的覆牙合、覆盖变化(n=10) Table 2 Changes of overbite and overjet in mixed-dentition children with anterior crossbite after using eruption guidance appliance (n=10)
2.4 上、下颌拥挤度的变化

如表3所示, 经过萌出诱导矫治器治疗, 上、下颌拥挤度的减小均差异具有统计学意义。

表3 混合牙列期个别前牙反牙合儿童经萌出诱导矫治器治疗后上、下颌拥挤度的变化(n=10) Table 3 Changes of the severity of upper and lower crowding in in mixed-dentition children with anterior crossbite after using eruption guidance appliance (n=10)
2.5 典型病例

病例1, 女性, 8岁, 双侧上中切牙反牙合, 反覆牙合-1.58 mm, 反覆盖-2.65 mm, 上颌拥挤度3 mm, 下颌拥挤度4 mm(图3)。佩戴萌出诱导矫治器9个月后, 反牙合解除, 上颌左、右中切牙分别唇向移动了4.61 mm、2.81 mm, 下颌左、右中切牙分别唇向移动了1.59 mm、2.92 mm, 治疗后的覆牙合为0.25 mm, 覆盖为2.08 mm, 上颌拥挤度为1 mm, 下颌拥挤度为0 mm(图4)。

图3 病例1矫治前口内相及影像学资料Figure 3 Pre-operative intraoral images and X-ray results in case 1
A, class Ⅰ primary canine relationship in right side; B, crossbites of bilateral upper central incisors; C, class Ⅰ primary canine relationship in left side; D, upper crowding was 3 mm; E, lower crowding was 4 mm; F, overbite was -1.58 mm, and overjet was -2.65 mm; G, no absence of permanent teeth on panoramic radiograph; H, skeletal class Ⅰ , average angle on cephalometric analysis.

图4 病例1矫治后口内相Figure 4 Post-operative intraoral images in case 1
A, class Ⅰ molar relationship and class Ⅰ primary canine relationship in right side; B, crossbites of bilateral upper central incisors were corrected; C, class Ⅰ molar relationship and class Ⅰ primary canine relationship in left side; D, upper crowding was 1 mm; E, lower crowding was 0 mm; F, overbite was 0.25 mm, and overjet was 2.08 mm.

病例2, 男性, 7岁9个月, 因右上乳中切牙滞留导致右上中切牙反牙合, 覆牙合 2.16 mm, 覆盖4.05 mm, 上颌拥挤度2 mm, 下颌拥挤度2 mm(图5)。拔除滞留乳牙后2周开始佩戴萌出诱导矫治器, 2个月后, 反牙合解除, 右上中切牙唇向移动了3.60 mm, 右下中切牙唇向移动了1.15 mm, 治疗后的覆牙合为1.45 mm, 覆盖为3.03 mm, 上颌拥挤度1 mm, 下颌拥挤度0 mm(图6)。

图5 病例2矫治前口内相及影像学资料Figure 5 Pre-operative intraoral images and X-ray results in case 2
A, class Ⅰ molar relationship and class Ⅰ primary canine relationship in right side; B, crosssbite of right upper incisor; C, class Ⅰ molar relationship and class Ⅰ primary canine relationship in left side; D, upper crowding was 2 mm; E, lower crowding was 2 mm; F, overbite was 2.16 mm, and overjet was 4.05 mm; G, no absence of permanent teeth on panoramic radiograph; H, skeletal class Ⅰ , average angle on cephalometric analysis.

图6 病例2矫治后口内相Figure 6 Post-operative intraoral images in case 2
A, class Ⅰ molar relationship and class Ⅰ primary canine relationship in right side; B, crosssbite of right upper incisor was corrected; C, class Ⅰ molar relationship and class Ⅰ primary canine relationship in left side; D, upper crowding was 1 mm; E, lower crowding was 0 mm; F, overbite was 1.45 mm, and overjet was 3.03 mm.

3 讨论

个别前牙反牙合是混合牙列期儿童常见的一种错牙合畸形, 原因包括骨性, 牙源性和功能性[8]。有研究发现在混合牙列期治疗牙源性的前牙反牙合, 可以重新建立适当的肌肉平衡[9], 可以有效改善上唇位置及面型[10], 矫治后上切牙向唇侧移动, 牙弓扩大, 从而为尖牙的萌出提供空间[11]。

理想的矫治方法应该是简单的、非侵入性的, 较少的椅旁时间, 更易被患儿接受, 并且能在较短的时间内对反牙合进行纠正。有研究表明[12, 13, 14], 固定矫治器和常规活动矫治器在混合牙列期纠正个别前牙反牙合疗效相似, 但均因白天佩戴时间较长, 对患儿面部美观、社交有一定影响。

本研究结果显示, 萌出诱导矫治器在矫正上切牙反牙合的过程中, 上切牙不仅存在唇向移位, 还存在垂直向及水平向的调整, 而相应下切牙也存在三维方向的改变。在上切牙唇向移动的过程中, 下切牙根据萌出诱导矫治器中预成的标准咬合关系主要进行唇向移动。上、下切牙垂直向的变化, 可能与上、下切牙唇向移动有关, 从而也造成了矫治后的覆牙合明显减小。上切牙水平向的变化与上切牙反牙合纠正后, 上颌牙弓长度增长, 牙齿拥挤解除, 而下切牙在矫治器预成的标准咬合关系的作用下也进一步趋向于排齐。王郁等[15]对11例混合牙列期存在上中切牙间隙的患儿应用萌出诱导矫治器治疗后, 发现该矫治器在关闭上中切牙间隙的同时有排齐牙齿, 纠正深覆牙合、深覆盖的作用。Keski等[5, 6]和Myrlund等[16]发现在芬兰儿童中早期戴用萌出诱导矫治器后, 有助于儿童咬合趋于安氏Ⅰ 类关系, 覆牙合、覆盖趋于正常, 牙齿排齐及促进下颌骨发育。本研究发现应用萌出诱导矫治器治疗个别前牙反牙合的过程中, 还有建立正常覆牙合、覆盖以及排齐牙齿的作用。因萌出诱导矫治器在国内开展的时间较短, 未来还需要大样本的研究来明确该矫治器在中国儿童混合牙列期的错牙合畸形早期矫治中的作用。

对于个别前牙反牙合的矫治方法有很多, 但一般均需在牙齿上粘接附件, 白天戴用时间较长, 对患儿社交和美观造成一定影响。而萌出诱导矫治器不需要在牙齿上粘接附件, 减少对牙齿损伤的可能, 同时也减少了因附件脱落, 多次就诊的椅旁时间; 患儿在上学期间无需佩戴, 最大限度满足了患儿的美观要求, 更易被患儿及其家长接受; 方便摘戴, 利于清洁, 也减少了患儿的患龋风险及牙龈疾病的发生。

综上所述, 萌出诱导矫治器可以在混合牙列早期治疗个别前牙反牙合, 同时有建立正常覆牙合、覆盖, 排齐牙齿的作用。

The authors have declared that no competing interests exist.

参考文献
[1] Felicity B, David B. Early correction of anterior crossbites: a systematic review[J]. J Orthod, 2011, 38(3): 175-184. [本文引用:2]
[2] Jones JW, O’Neill PD. Anterior crossbite and mobile lower central incisors in a 7-year-old patient: a case report[J]. Dent Update, 1996, 23(7): 271-274. [本文引用:1]
[3] Thiland er B, Rubio G, Pena L, et al. Prevalence of temporomand ibular dysfunction and its association with malocclusion in children and adolescents: an epidemiologic study related to specified stages of dental development[J]. Angle Orthod, 2002, 72(2): 146-154. [本文引用:1]
[4] Eluza P, Leonardo SA, Marcia RTCA, et al. Quality of life follo-wing early orthodontic therapy for anterior crossbite: report of cases in twin boys[J]. Case Rep Dent, 2016, 9(1): 1-5. [本文引用:1]
[5] Keski NK, Hernesniemi R, Heiskanen M, et al. Orthodontic intervention in the early mixed dentition: a prospective, controlled study on the effects of the eruption guidance appliance[J]. Am J Orthod Dentofacial Orthop, 2008, 133(2): 254-260. [本文引用:2]
[6] Keski NK, Keski NL, Salo H, et al. Dentoficial changes after orthodontic intervention with eruption guidance appliance in the early mixed dentition[J]. Angel Orthod, 2008, 78(2): 324-331. [本文引用:2]
[7] 傅民魁, 林久祥. 口腔正畸学[M]. 2版. 北京: 北京大学医学出版社, 2014: 65-69. [本文引用:1]
[8] Zegan G, Dascalu CG, Mavru Rb, et al. Risk factors and predictors of crossbite at children[J]. Rev Med Chir Soc Med Nat Iasi, 2015, 119(2): 564-571. [本文引用:1]
[9] Chow MH. Treatment of anterior crossbite caused by occlusal interferences[J]. Quintessence Int Dent Dig, 1979, 10(2): 57-60. [本文引用:1]
[10] Paulo AS. Angle class I malocclusion with anterior negative overjet[J]. Dental Press J Orthod, 2016, 21(2): 102-114. [本文引用:1]
[11] Rabie AB, Gu Y. Diagnostic criteria for pseudo-Class Ⅲ malocclusion[J]. Am J Orthod Dentofacial Orthop, 2000, 117(1): 1-9. [本文引用:1]
[12] Anna PW, Lars B. Fixed versus removable orthodontic appliances to correct anterior crossbite in the mixed dentition- a rand omized controlled trial[J]. Eur J Orthod, 2015, 37(2): 123-127. [本文引用:1]
[13] Anna PW, Anders N, Sofia P, et al. A cost minimization analysis of early correction of anterior crossbite: a rand omized controlled trial[J]. Eur J Orthod, 2016, 38(2): 140-145. [本文引用:1]
[14] Anna PW, Lars B. Stability of anterior crossbite correction: A rand omized controlled trial with a 2-year follow-up[J]. Angle Or-thod, 2015, 85(2): 189-195. [本文引用:1]
[15] 王郁, 赵一姣, 李成皓, 等. 萌出诱导矫治器治疗儿童上颌中切牙间隙的临床初探及三维数字化技术分析[J]. 中华口腔正畸学杂志, 2015, 22(2): 91-95. [本文引用:1]
[16] Myrlund R, Dubland M, Keski NK, et al. One year treatment effects of the eruption guidance appliance in 7- to 8-year-old children: a rand omized clinical trial[J]. Eur J Orthod, 2015, 37(2): 128-134. [本文引用:1]