上下颌联合扩弓矫治青少年安氏Ⅰ类错（牙合）的相关研究

发布时间：2018-08-13 11:20

【摘要】：Angle在1860年首次提出利用扩大腭中缝进行上颌扩展来解决牙弓横向发育不足、牙弓狭窄、牙列拥挤、后牙反合等错合畸形问题,至今,上颌扩弓技术已经在临床应用了一个多世纪并发展的极为成熟。但单纯的上颌扩弓不能解决下颌牙列拥挤等问题,并使下颌牙弓与扩大的上颌难以匹配。下颌骨由于解剖结构的特殊性导致其扩弓的可行性一直备受学者们的质疑。直到1962年,Walter通过临床观察提出下颌扩展的可行性,1982年Sandstorm发表了第一篇有关下颌扩弓的临床报道。目前国内外对下颌扩弓进行了大量的研究,但鲜少有关于上下颌联合扩弓矫治牙列拥挤的临床报道,我院正畸科教授针对下颌骨特殊的解剖结构,将改良制作的下颌钢网式螺旋扩大器应用于临床,至今已成功矫治百余例。通常认为上颌快速扩弓产生的矫形力作用于牙齿和骨组织,打开腭中缝的同时导致支抗牙的轻度颊向倾斜和牙槽骨板的倾斜弯曲,同时伴随骨改建。关于下颌扩弓,目前主要观点认为主要是由于牙齿的颊倾带来宽度的增加。国内目前对上下颌联合扩弓的临床报道较少,且多为个案报道,对于扩弓前后,牙颌、牙齿与牙槽骨变化的系统研究也较少。相较于X线片检查,近年来锥体束CT的应用使测量内容更加全面,测量更加精确可靠,为我们评价上下颌联合扩弓产生牙齿及颌骨的变化提供了有效手段。以往研究一般基于模型测量及X线片研究,本实验通过扩弓前后牙合模型的测量,分析上下颌联合扩弓对上下颌牙列拥挤度及牙弓周长变化的影响,通过对截取的扩弓前后正中矢状面进行定点测量,观察扩弓前后软硬组织变化,通过MIMICS17.0软件对扩弓前后的CBCT影像进行定点测量,评估青少年安氏Ⅰ类患者经过上下颌联合扩弓后牙颌及侧貌变化、牙弓形态、支抗磨牙及其牙槽骨的变化,为临床应用上下颌联合扩弓技术提供一定参考。研究目的本实验以应用上下颌联合扩弓矫治牙列拥挤的25名青少年安氏Ⅰ类患者为研究对象,对其扩弓前及保持三个月后拆除扩弓器时的牙合模型及CBCT影像进行测量,对比其前后测量结果,探讨上下颌联合扩弓对牙列拥挤度及牙弓周长的影响,以及扩弓过程中软硬组织与牙弓形态的改变、支抗磨牙及相应牙槽骨的倾斜变化和宽度变化,为上下颌联合扩弓的临床应用提供参考。研究方法对纳入研究的25例青少年安氏Ⅰ类错合畸形患者,在其扩弓前,扩弓后保持三个月拆除扩弓器时分别取牙颌模型,拍摄CBCT影像。在牙颌模型上测量上下颌牙列拥挤度及牙弓周长,截取CBCT正中矢状面影像的测量内容包括反应硬组织变化和唇部软组织变化的指标,运用MIMICS17.0软件对所有CBCT影像进行同名牙牙冠和牙根宽度的测量,对上颌两侧第一磨牙及其牙槽骨的角度变化、下颌两侧第一磨牙的角度变化进行测量,对上颌鼻底平面、硬腭平面、颊腭侧牙槽嵴顶对应的上颌骨宽度,下颌两侧第一磨牙的CEJ、颊舌侧牙槽骨的对应宽度进行测量。所有测量工作均由作者本人完成,每项数据分别测量三次,每次测量间隔一周,三次测量结果取平均值,应用SPSS19.0统计软件对扩弓前后的数据进行配对t检验等相关统计学分析。结果扩弓前后各测量结果对比统计显示1.上下颌牙列拥挤度明显减小且变化具有统计学意义(P0.05),上下颌牙弓周长增加,变化具有统计学意义(P0.05)。2.CBCT正中矢状面影像软硬组织测量结果显示,下颌平面角稍增大,上下切牙稍有唇倾,但变化均无统计学意义(P0.05),上下唇凸点至审美平面距离均有减小,但变化也无统计学意义(P0.05)。3.上下颌牙冠及牙根宽度均有增加,且变化具有统计学差异(P0.05),牙冠宽度增加量稍大于牙根宽度增加量,且宽度增加呈现前磨牙区最大,磨牙区次之,尖牙区最小的趋势。4.上颌第一磨牙的倾斜角度变化无统计学意义(P0.05),但上颌牙槽骨倾斜角度和下颌第一磨牙倾斜角度的变化有统计学意义(P0.05),说明上下颌联合扩弓时,上颌支抗磨牙基本未发生倾斜,而上颌左右侧牙槽骨倾斜角度分别增加约10.75°和8.61°,下颌左右侧第一磨牙分别颊向倾斜约7.74°和7.18°。5.上颌第一磨牙牙槽骨各线距均有增加,变化有统计学意义(P0.05)。鼻底平面对应宽度增加约3.95mm,硬腭平面对应宽度增加约5.90mm,颊舌侧牙槽嵴顶对应宽度分别增加约6.37mm和5.09mm,总体趋势与牙槽骨倾斜变化一致。6.下颌第一磨牙区域的颊舌侧牙槽骨宽度均得到增加,变化具有统计学意义(P0.05),釉牙骨质界宽度增加(约4.39mm)较牙冠宽度增加(约5.98mm)较小,但从牙槽骨颊舌侧宽度增加幅度看来,釉牙骨质界下2mm处与7mm处,颊舌侧骨板增加量基本一致。结论1.上下颌联合扩弓可有效开辟间隙,增加牙弓周长,解决青少年横向发育不足和牙列拥挤等问题。2.扩弓前后面部软硬组织并未发生明显变化。3.上颌扩弓时,上颌支抗磨牙基本未发生倾斜,可视为整体移动,主要为上颌腭中缝的开展及牙槽骨的倾斜。4.改良钢网式扩弓器对下颌的扩弓作用不单单是牙齿的颊倾,而是牙齿颊向移动的同时伴随牙根的移动和牙槽骨的改建。
[Abstract]:Angle first proposed in 1860 to expand the maxillary arch by enlarging the middle palatal suture to solve the problems of malocclusion, such as underdevelopment, narrow arch, crowded dentition, occlusion of posterior teeth, etc. Up to now, maxillary arch expansion technology has been used in clinical practice for more than a century and developed very mature. But simple maxillary arch expansion can not solve the problem of mandibular dentition. The feasibility of mandibular arch expansion was questioned by scholars because of the anatomical structure of the mandible. Until 1962, Walter proposed the feasibility of mandibular expansion through clinical observation. Sandstorm published the first clinical report on mandibular arch expansion in 1982. At present, a large number of studies have been done on mandibular expansion, but few reports have been reported on the treatment of crowded dentition with combined maxillary and mandibular expansion. In view of the special anatomical structure of the mandible, our orthodontic professor has applied the modified mandibular steel mesh spiral expander to the clinic. Up to now, more than 100 cases have been corrected successfully. The orthodontic force produced by rapid expansion of the arch acts on the teeth and bone tissues, opening the middle palatal seam and leading to a slight buccal inclination of the anchorage teeth and an oblique bending of the alveolar bone plate, accompanied by bone remodeling. Compared with X-ray examination, the application of cone-beam CT in recent years makes the measurement more comprehensive, more accurate and reliable, and provides a basis for evaluating the changes of teeth and jaws caused by combined maxillary and mandibular expansion. Previous studies were generally based on model measurements and X-ray studies. In this study, the effects of combined maxillary and mandibular arch expansion on crowding degree and periodontal length of maxillary and mandibular dentition were analyzed by measuring occlusal models before and after arch expansion. Objective To evaluate the changes of maxillary and lateral appearance, arch shape, anchorage molars and alveolar bones of the juvenile Angle class I patients after combined maxillary and mandibular arch expansion by measuring CBCT images before and after the expansion with MIMICS 17.0 software. The occlusal models and CBCT images of 25 adolescents with Class I dentition crowding treated with maxillary and mandibular combined arch expansion were measured before and three months after the arch expansion. The effects of maxillary and mandibular combined arch expansion on the crowding degree and periodontal length of dental arch were compared. The changes of the morphology of the soft and hard tissues and arch, the inclination and width of the anchorage molars and the corresponding alveolar bones during the course of the arch expansion can provide reference for the clinical application of combined maxillary and mandibular arch expansion. The crowding degree of maxillary and mandibular dentition and the circumference of dental arch were measured on the dental model. The measurement contents of CBCT median sagittal plane included the indexes reflecting the changes of hard tissue and lip soft tissue. The width of crown and root of all CBCT images were measured by MIMICS 17.0 software. The angles of the first molars on both sides of the jaw and their alveolar bones, the angles of the first molars on both sides of the jaw were measured. The maxillary width corresponding to the maxillary floor, hard palate, buccal and palatal alveolar crest, the CEJ of the first molars on both sides of the jaw, and the corresponding width of the alveolar bone on the buccal and lingual sides were measured. Completed, each data were measured three times, one week interval between each measurement, three measurements were taken to average, the data before and after the expansion of the paired t-test and other statistical analysis. Significance (P 0.05), maxillary and mandibular arch circumference increased, the change was statistically significant (P 0.05). 2. CBCT median sagittal imaging soft and hard tissue measurement results showed that the mandibular plane angle slightly increased, the upper and lower incisors slightly inclined lip, but the change was not statistically significant (P 0.05), the upper and lower lip bump to the aesthetic plane distance were reduced, but the change was not statistically significant. Significance (P 0.05). 3. The crown and root widths of maxillary and mandibular teeth increased significantly (P 0.05). The increase of crown width was slightly larger than that of root width. The increase of crown width showed the largest in premolar area, the second in molar area, and the smallest in canine area. 4. There was no significant difference in the inclination angle of maxillary first molar (P 0.05). However, the maxillary alveolar inclination angle and the mandibular first molar inclination angle were significantly different (P 0.05), indicating that the maxillary anchorage molars did not incline, the maxillary alveolar inclination angle increased by 10.75 degrees and 8.61 degrees respectively, and the mandibular first molars inclined by 7.74 degrees and 7.61 degrees respectively. Alveolar bone spacing of maxillary first molars increased significantly (P 0.05). The corresponding width of nasal floor increased by 3.95 mm, that of hard palate increased by 5.90 mm, and that of buccolingual alveolar ridge increased by 6.37 mm and 5.09 mm, respectively. The overall trend was consistent with that of alveolar bone inclination. The width of the alveolar bone on the buccal-lingual side of the alveolar bone increased significantly (P 0.05). The width of the enamel-cementum boundary increased slightly (about 4.39 mm) than that of the crown (about 5.98 mm). However, the increase of the alveolar bone width on the buccal-lingual side of the alveolar bone was similar to that on the buccal-lingual side at the 2 mm and 7 mm below the enamel-cementum boundary. The expansion of the maxillary arch can effectively open the space, increase the perimeter of the arch, and solve the problems of underdevelopment and crowded dentition in adolescents. 4. The effect of modified steel mesh expander on mandibular expansion is not only the buccal inclination of teeth, but also the buccal movement of teeth accompanied by root movement and alveolar bone remodeling.
【学位授予单位】：大连医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R783.5

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