Unpredictability of soft tissue changes after camouflage treatment of Class II division 1 malocclusion with maximum anterior retraction using miniscrews

Objective:To compare soft and hard tissue responses based on the degree of maxillary incisor retraction using maximum anchorage in patients with Class II division 1 malocclusion.Materials and Methods:This retrospective study sample was divided into moderate retraction (<8.0 mm; n = 28) and maximum retraction (≥8.0 mm; n = 29) groups based on the amount of maxillary incisor retraction after extraction of the maxillary and mandibular first premolars for camouflage treatment. Pre- and posttreatment lateral cephalograms were analyzed.Results:There were 2.3 mm and 3.0 mm of upper and lower lip retraction, respectively, in the moderate group; and 4.0 mm and 5.3 mm, respectively, in the maximum group. In the moderate group, the upper lip was most influenced by posterior movement of the cervical point of the maxillary incisor (β = 0.94). The lower lip was most influenced by posterior movement of B-point (β = 0.84) and the cervical point of the mandibular incisor (β = 0.83). Prediction was difficult in the maximum group; no variable showed a significant influence on upper lip changes. The lower lip was highly influenced by posterior movement of the cervical point of the maxillary incisor (β = 0.50), but this correlation was weak in the maximum group.Conclusions:Posterior movement of the cervical point of the anterior teeth is necessary for increased lip retraction. However, periodic evaluation of the lip profile is needed during maximum retraction of the anterior teeth because of limitations in predicting soft tissue responses.     

拔除第一磨牙矫治牙列拥挤的病例分析

目的总结拔除第一磨牙矫治牙列拥挤的病例资料，分析矫治的难点和要点，为临床工作提供参考。方法本组病例为中山大学光华口腔医学院正畸科牙列拥挤患者22例，男性8例，女性14例，年龄11．3—26．7岁，平均16．5岁。拔除1—4颗第一恒磨牙进行矫治，其中拔除4颗第一磨牙5例，拔除3颗第一磨牙1例，拔除2颗第一磨牙4例，拔除1颗第一磨牙12例。结果患者矫治时间为14—25个月，平均18．5个月，矫治后患者前牙覆骀、覆盖正常，后牙咬合关系良好，牙弓间隙全部关闭，面部侧貌协调。结论拔除第一磨牙矫治牙列拥挤，应注重严格掌握适应证及相应的矫治技巧和方法，才能达到良好的矫治效果。     

Changes in facial profile during orthodontic treatment with extraction of four first premolars

The present study was designed to evaluate soft tissue profile changes after the orthodontic treatment of class I bimaxillary dentoalveolar protrusion in adult cases. Pre- and post-treatment cephalograms of 20 Caucasian female class I bimaxillary dentoalveolar protrusion patients were selected from private practice. All of them were treated by extraction of four first premolars, and banded and bonded by 022 × 028 standard edgewise technique. t-Test was used to analyze pre- and post-treatment cephalograms. This study showed that upper and lower lip protrusions were decreased respectively 2.7 ± 2.9 mm (p < 0.001) and 2.8 ± 2.8 mm (p < 0.001). The mean changes of upper and lower lip thickness and length, as well as nasolabial and labiomental angles were not significant. Significant positive correlation was found between changes of maxillary and mandibular incisors with changes in upper lip (r_UI = 0.70, p < 0.001, r_LI = 0.59, p < 0.006) and the lower lip positions (r_UI = 0.64, p < 0.002, r_LI = 0.72, p < 0.001). By using stepwise regression it was found that a ratio of 0.63:1 was obtained between upper lip retraction and maxillary incisor retraction and a ratio of 0.62:1 was obtained between lower lip retraction and mandibular incisor changes. This study concluded that, a strong correlation exists between anterior tooth retraction and the position of both lips.     

Split-mouth comparison of Physics forceps and extraction forceps in orthodontic extraction of upper premolars

We compared outcome variables (operative complications, inflammatory complications, and operating time) in patients being treated by orthodontic extraction of upper premolars with the Physics forceps or the universal extraction forceps. We organised a single blind, split-mouth clinical trial to compare the outcomes of the 2 groups (n = 54 premolars). The Physics forceps group had lower mean (SD) visual analogue scores (VAS) for pain (0.59 (0.57)) on the first postoperative day than the other group (1.04 (0.85)) (p = 0.03). There were no other significant differences between the 2 groups in any other variable studied.     

不同矫治技术对牙周炎患者上切牙区牙槽骨改变的影响

目的： 探讨不同矫治技术治疗牙周炎对患者上切牙区牙槽骨密度、高度及龈沟出血变化的影响。方法： 选取2016年1月—2019年12月萍乡市人民医院口腔科行正畸治疗的中度牙周炎患者23例,按照随机数字表法分为实验组（n=12）和对照组（n=11）,实验组采用无托槽隐形矫治器治疗,对照组采用常规唇侧固定矫治器治疗,比较2组治疗前、后龈沟出血指数、探诊深度、上切牙区牙槽骨骨高度和骨密度变化。采用SPSS 22.0软件包对数据进行统计学分析。结果： 治疗后2组上切牙区腭侧牙槽嵴顶处（L1）骨密度降低,实验组下降率显著小于对照组（P<0.05）。治疗后对照组上切牙区解剖根尖点冠方1 mm处（L3）骨密度显著减低,但实验组无明显变化。治疗前、后2组上切牙区牙槽骨高度无显著变化（P>0.05）。实验组上切牙牙根吸收程度显著低于对照组（P<0.05）。实验组上切牙压入量显著高于对照组（P<0.05）。治疗后2组探诊深度、龈沟出血指数均降低,且实验组变化量显著大于对照组（P<0.05）。结论： 采用无托槽隐形矫治器治疗牙周炎,较常规唇侧固定矫正更有利于上切牙区牙槽骨骨密度恢复,且两者对骨高度影响相同,两者均为安全有效的正畸治疗方式。     

MBT技术矫治成年与青少年双颌前突软硬组织改变及相关性分析

目的采用3M unitek MBT托槽拔牙矫治双颌前突的成人及青少年,研究治疗前后软硬组织的变化情况,预测矫治后的疗效。方法选择双颌前突病例30例,成人15例,青少年15例。拔除4个第一双尖牙,使用3MMBT矫治器进行矫治,对矫治前后的38项软硬组织指标进行对比,通过配对t检验评价软硬组织变化的情况。结果经拔牙矫治,成人患者主要发生切牙内收和唇部突度减小,与治疗前相比有显著性差异,但无骨性相关;而青少年软组织面型改变不仅与牙性指标有一定的相关性,而且与下颌骨的生长有关。结论MBT矫治技术矫治成人与青少年双颌前突可以改善面部的软组织平衡,但并没有改变矢状骨骼类型,该技术可以很好地进行垂直向的控制。     

Comparative CBCT analysis of the changes in buccal bone morphology after corticotomy and micro-osteoperforations assisted orthodontic treatment – Case series with a split mouth design

Purpose

Procedures such as Periodontally Accelerated Osteogenic Orthodontics (PAOO) support the use of osteotomy to aid tooth movement and rapid distraction of the periodontal ligament by utilizing tissue engineering principles with periodontal regenerative surgery. The aim of this study was to evaluate and compare the amount of tooth movement and the associated changes in buccal bone morphology between corticotomy and flapless Micro-Osteoperforation (MOP) assisted orthodontic treatment.

Class II division 1 malocclusion treated with extraction of upper first premolars: Case report

This report describes the treatment of a 13.7-year-old girl with a severe maxillary protrusion. She indicated Class II molar and canine relationship and showed 7-mm overjet, 0-mm overbite, and slight lower midline deviation with an unstable mandibular position. Treatment was started using a splint to stabilize the position of the mandible, followed by extractions of maxillary first premolars and fixed appliances to reduce lip protrusion. Molars were finished in a Class II relationship with canine guidance, and ideal overjet and overbite relationships were established. Also the final result was esthetically well balanced. The treatment results were stable 6 years after debonding.     

SDF-1在拔牙创软组织愈合过程中的表达及分布

目的:观察拔牙创软组织内基质细胞衍生因子l(SDF-1)的表达及分布,为促进拔牙创愈合提供新思路。方法:Wistar雄性大鼠30只,随机分为10组,每组3只,分别拔除左侧下颌第一磨牙。于拔牙后1、2、4、7、10 d分别采用免疫组织化学染色和RT-PCR技术观察SDF-1在创缘软组织内的分布及表达变化情况。采用SPSS12.0软件包对数据进行统计学分析。结果:免疫组织化学染色显示,拔牙早期创口周围牙龈组织内SDF-1表达增强,染色部位主要分布于牙龈上皮的棘层及基底层细胞胞质与细胞间。越靠近基底层细胞,染色越明显。拔牙后4 d,阳性染色部位主要位于基底细胞层,新生肉芽组织内可见新生血管的内皮细胞和增殖活跃的成纤维细胞阳性表达。拔牙后7 d,牙龈上皮细胞层染色变得均匀,固有层可见少量阳性染色的新生血管内皮细胞及成纤维细胞;拔牙后10 d,牙龈上皮染色特点基本与正常牙龈相似。实时定量PCR检测结果表明,SDF-1mRNA的表达水平在拔牙后1 d达到最高（P<0.01）,第2天开始下降(P<0.05),拔牙后4 d出现第2次峰值（P<0.01）,7 d后其表达水平仍高于对照组(P<0.05),10 d时恢复正常水平(P>0.05)。结论:SDF-1参与拔牙创软组织的早期愈合过程,可能对拔牙创的愈合起着一定的促进作用。