安氏Ⅱ~1类错牙合拔牙矫治后牙弓形态变化的计算机辅助分析研究

发布时间：2018-04-03 13:23

本文选题：安氏Ⅱ1类错牙合　切入点：拔牙矫治　出处：《第四军医大学》2014年硕士论文

【摘要】：安氏Ⅱ1类错牙合在我国恒牙期青少年错牙合畸形中约占23.8％，临床主要表现为上颌前突、下颌后缩，前牙区深覆牙合、深覆盖。对于这种错牙合畸形，拔牙矫治是一种常用的矫治方法，其目的在于利用上颌拔牙间隙解除拥挤，内收上前牙，缓解深覆盖；利用下颌拔牙间隙整平Spee曲线，矫治深覆牙合，同时前移下后牙，改善磨牙远中关系。拔牙矫治一般会带来牙弓形态的改变，而牙弓形态的这些变化主要体现在牙弓宽度、长度以及牙弓曲线的改变上。安氏Ⅱ1类错牙合畸形在拔牙矫治后牙弓形态变化的程度，与矫治作用机制密切相关，直接关系到正畸临床矫治效果的稳定性。本研究通过选择拔除4个第一前磨牙的安氏Ⅱ1类错牙合患者，分析比较患者在矫治前后牙弓不同部位牙弓宽度、长度及整体牙弓曲线的变化规律，从而分析其矫治作用机制，为临床治疗该类畸形确定治疗方案、同时也为进一步研究该类型错牙合畸形矫治效果的稳定性提供参考。论文由两部分组成：第一部分：牙弓形态计算机辅助分析方法的建立。本部分研究的目的是针对安氏Ⅱ1类错牙合拔牙矫治后牙弓形态变化研究的需要，建立一种能够进行牙弓宽度、长度测量及牙弓曲线形态特征分析的计算机辅助分析方法。具体研究内容、测量实现途径如下： 1．获取三维数字化牙颌模型：利用Zenotec Scan S100三维激光扫描仪对患者矫治前、后的石膏模型进行扫描，得到以*.stl格式（三角网格形式）存贮的三维表面点云文件，通过Geomagic Studio逆转录软件进行去除噪点、平滑补洞、拼合减点等处理，获得精细的三维数字化牙颌模型。 2．牙弓曲线形态参数的提取：采用逆向工程(Reverse Engineering)原理，使用Visual Studio2005和视觉化工具函式库(VTK，Visualization Toolkit)等平台作为开发工具，建立牙弓曲线计算机拟合系统。利用该系统，首先确定牙弓形态测量平面，然后确定三维数字化牙颌模型表面牙弓曲线拟合用标志点及其在测量平面生成牙弓曲线拟合用点，最后实现牙弓曲线的拟合及拟合用点坐标的导出等功能，完成牙弓曲线形态参数的提取。 3．牙弓形态计算机辅助分析方法的功能实现：将牙弓曲线形态参数导入MATLAB软件，进行相应的数学运算任务编程，实现牙弓曲线上不同部位牙弓宽度、长度的测量及牙弓曲线形态特征分析等功能。第二部分：安氏Ⅱ1类错牙合拔牙矫治后牙弓形态变化的研究。目的：分析安氏Ⅱ1类错牙合患者拔牙矫治后牙弓形态各个方面的变化规律，为正畸临床中治疗方案的确定提供参考。方法：选取30例安氏Ⅱ1类错牙合病例，分别取拔牙矫治前、后的石膏模型进行三维（3D，Three dimensional）激光扫描，获取数字化牙颌模型，利用本研究中所建立的牙弓曲线计算机拟合系统拟合出相应牙弓曲线并提取拟合用点的三维坐标，导入MATLAB软件进行数学运算任务编程，计算上下牙弓治疗前后不同部位牙弓宽度、长度的数值。通过配对t检验方法对矫治前后不同部位牙弓宽度、长度的变化进行统计学分析；通过生成治疗前、后牙弓形态测量分析平面上牙弓曲线拟合用点的平均牙弓曲线，比较分析安氏Ⅱ1类错牙合拔牙矫治后牙弓形态的变化。结果：（1）牙弓宽度变化：安氏Ⅱ1类错牙合患者经矫治后，上颌前部牙弓宽度侧切牙区、尖牙区虽有增加，但增加的量较小，侧切牙区宽度增加了1.74±1.48mm(P＜0.01)，尖牙区宽度增加了0.90±1.20mm(P＜0.05)。上颌后部牙弓宽度在各个牙位均明显减小，第二前磨牙及第一磨牙间的宽度相对于前牙区的变化量较大，分别减小了4.08±1.32mm（P＜0.001)、3.19±1.35mm（P＜0.001)，而第二磨牙间的宽度减小量下降为1.89±0.96mm（P＜0.001)。下颌牙弓的宽度变化与上颌基本是一致的，前部牙弓宽度仅在中切牙区有少量增加治疗前后增加了0.26±0.30mm（P＜0.05)，侧切牙及尖牙区则未见明显改变。下颌后部牙弓宽度呈现出与上颌后部牙弓相适应的减小性变化，第二前磨牙区牙弓平均宽度治疗后减小了4.47±3.06mm（P＜0.001)，第一磨牙区牙弓宽度减小了2.48±1.80mm（P＜0.001)，而第二磨牙区牙弓宽度治疗前后未见明显变化。（2）牙弓长度变化：安氏Ⅱ1类错牙合患者经矫治后，上颌尖牙区牙弓长度增加1.18±1.19mm（P＜0.05)，，增加量比较小，而上颌后部第二前磨牙、第一磨牙及第二磨牙区牙弓长度分别减少了5.96±3.14mm（P＜0.001)，6.53±2.04mm（P＜0.001)及6.35±1.79mm（P＜0.001)，其长度的变化量要大于前部牙弓。下颌牙弓前部及后部长度的变化与上颌是一致的。（3）牙弓弓形形态的变化：根据30例患者治疗前后所有的牙弓曲线拟合用点计算出上下颌矫治前后的平均点分布图，从分布图展现出来的牙弓弓形形态看，治疗前后上、下颌牙弓的弓形形态基本是一致的，没有发生明显的变化。结论：本研究的上述结果提示，对于安氏Ⅱ1类错牙合拔牙矫治来说，其矫治后牙弓形态没有发生明显的改变。对于这些安氏Ⅱ1类错牙合拔牙矫治前后牙齿位置在矢状向上存在明显位移的患者，左右两侧同名牙间的宽度变化并不能准确地反映牙弓弓形宽度的变化。结合本研究关于矫治后牙弓长度在前、后部均有减低的结果进行分析，安氏Ⅱ1类错牙合拔牙矫治后，上述左右同名牙间宽度的变化的一个重要机制为矢状向上牙齿位置的前后移动，造成了其在水平横向上宽度及长度的变化。本研究的结果说明，牙弓形态的拟合提取在分析拔牙患者的牙弓形态的变化中的重要作用，本研究中建立的牙弓形态计算机辅助分析方法，可作为牙弓形态的拟合提取工具，有一定的推广应用价值。
[Abstract]:Class II Division 1 malocclusion in permanent dentition malocclusion teenagers in China accounted for about 23.8% anomalies, the main clinical manifestations of maxillary protrusion, mandibular retrusion, anterior deep overbite, deep overjet. For this kind of malocclusion, orthodontic extraction is a commonly used treatment method, its purpose in the extraction of tooth space lift congestion, adduction of upper anterior teeth, alleviate the deep overburden; using mandibular extraction space leveling Spee curve, correction of deep overbite, and forward under the posterior teeth, improve the relationship between the molars. Extraction treatment typically leads to the change in arch form, and these changes mainly reflected the state of dental arch width in the dental arch, and the length of the dental arch curve changes.
Class II Division 1 malocclusion after extraction treatment of dental arch shape change degree is closely related with the treatment mechanism, directly related to the stability of orthodontic clinical treatment effect. This study through the selection of extraction of 4 first premolar of the class II Division 1 malocclusion patients, compared with the width of the teeth before and after treatment different parts of the dental arch arch, and the whole length changes of dental arch curve, then analyzes its treatment mechanism, this kind of deformity to determine treatment options for clinical treatment, but also provide a reference for the malocclusion treatment effect the stability of further research of this type of fault.
The paper consists of two parts:
The first part: the establishment of computer aided analysis of dental arch.
The objective of this study is to meet the needs of class II Division 1 malocclusion tooth changes of posterior arch shape correction, can establish a dental arch width, analysis method of computer aided measurement and analysis of the length of the dental arch curve morphological characteristics. The specific research contents, measurement ways are as follows:
1. to obtain the 3D digital dental model: using Zenotec Scan S100 three-dimensional laser scanner in patients before treatment, after the plaster models were scanned with *.stl format (triangular form) 3D surface point cloud file storage, remove the noise by Geomagic Studio reverse transcription software for smooth hole filling, split point subtraction processing. Get the 3D digital dental model with fine.
Extraction of 2. morphological parameters of the dental arch curve by Reverse Engineering (Reverse Engineering) principle, using Visual Studio2005 and Visualization Toolkit (VTK Visualization Toolkit) platform as a development tool, the establishment of the dental arch curve fitting system. By using the computer system, first determine the arch form measuring plane, and then determine the three-dimensional the digital tooth surface of dental arch curve fitting combined point model and in the measurement plane generation dental arch curve fitting, and finally realize the fitting and fitting of dental arch curve by point coordinate export functions, complete the extraction of dental arch curve parameters.
3. methods of analysis of the arch form of computer aided functions: the dental arch curve shape parameter into MATLAB software, mathematical programming tasks corresponding to the implementation of the dental arch curve on different parts of the arch width, measurement and morphological characteristics of dental arch curve analysis function of length.
The second part: the study of class II Division 1 malocclusion tooth dental arch morphology treatment.
Objective: to analyze the changes of class II Division 1 malocclusion patients of posterior arch shape extraction treatment in various aspects, and provide some reference for orthodontic clinical treatment programs.
Methods: 30 cases of class II Division 1 malocclusion cases were taken before extraction treatment, the 3D model of gypsum (3D, Three dimensional) laser scanning, acquisition of digital dental model established in this study, using dental arch curve fitting computer system fitting the dental arch curve and extracted by fitting the three-dimensional coordinates of points, import MATLAB software for mathematical programming tasks, calculated before and after treatment in different parts of the dental arch width and length value. Through paired t test before and after treatment in different parts of the arch width and length changes were statistically analyzed; through the generation before treatment, analysis of posterior arch form measurement plane the dental arch curve fitting with the average dental arch curve points, comparative analysis of class H Division 1 malocclusion with extraction treatment changes of posterior arch form.
Results: (1) the changes of dental arch width: Class II Division 1 malocclusion patients after treatment, anterior maxillary lateral incisor width, canine area had increased, but the increase was smaller, the width of the lateral incisor area increased 1.74 + 1.48mm (P < 0.01), intercanine width increased by 0.90 + 1.20MM (P < 0.05). Posterior maxillary dental arch width were significantly decreased in all teeth, second premolars and first molar width variation with respect to the anterior region of the larger amounts were reduced by 4.08 (P < 0.001) + 1.32mm, 3.19 + 1.35mm (P < 0.001), and the second molar the width reduction decreased to 1.89 + 0.96mm (P < 0.001). The width changes with the maxillary mandibular arch is basically the same, the front arch width in only a small increase in the incisor region before and after treatment increased 0.26 + 0.30mm (P < 0.05), lateral incisor and canine posterior area did not change significantly. The dental arch width and showing The maxillary posterior arch adaptation decreased. The average width of dental arch in second premolar area decreased by 4.47 + 3.06mm after treatment (P < 0.001). The width of the first molar area decreased by 2.48 + 1.80mm (P < 0.001), while the second molar area arch width did not change significantly before and after treatment.
(2) changes the length of dental arch: Class II Division 1 malocclusion patients after treatment, the maxillary canine area arch length increased 1.18 + 1.19mm (P < 0.05), increase the amount is relatively small, and the posterior maxillary second premolar, first molar and two molar tooth arch length decreased respectively (5.96 + 3.14mm P < 0.001), 6.53 + 2.04mm (P < 0.001) and 6.35 + 1.79mm (P < 0.001). The variation of its length is greater than the anterior arch and the maxillary mandibular arch. Changes of the front and back length is the same.
(3) the changes of dental arch form: according to the dental arch curve fitting of all patients before and after treatment in 30 cases with the calculated average point before and after the treatment of mandibular distribution, from the distribution map show the dental arch form, before and after the treatment, the dental arch arch shape is basically the same, no significant changes.
Conclusion: the results of this study suggest that for class II Division 1 malocclusion extraction treatment, the treatment of dental arch form was not changed obviously. For these class II Division 1 malocclusion after extraction in tooth position in the sagittal direction has obvious displacement with the right and left sides of the teeth width the room does not accurately reflect the changes of dental arch width. Combined with the research on treatment of posterior arch length in front and rear were reduced by analyzing the results of the class II Division 1 malocclusion after extraction treatment, one of the important mechanisms of the change of width of the left and right teeth between the sagittal to move on the position of the teeth, resulting in the horizontal lateral width and length changes. The results of this study show that the fitting extraction of dental arch form an important role in the changes of dental arch form tooth extraction in this study. The computer aided analysis method of dental arch form established in this paper can be used as a fitting extraction tool for dental arch shape, and has certain popularization and application value.

【学位授予单位】：第四军医大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R783.5

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