Questionnaire survey on pain and discomfort after insertion of orthodontic buccal miniscrews,palatal miniscrews and,orthodontic miniplates

PurposeSkeletal anchorage devices have recently been developed for absolute anchorage during edgewise treatment. Such anchorage devices can be divided into miniplate and miniscrew types. However, the differences between these two types of appliance have not been sufficiently evaluated from the patient's point of view. Therefore, we surveyed patients for two weeks after insertion of miniplates and miniscrews in order to evaluate their pain and discomfort.Materials and methodsSixty-four patients were divided into the following three groups: maxillary buccal miniplate (Group A) (19 people, 38 plates); upper buccal miniscrew (Group B) (14 people, 27 screws); and maxillary palatal miniscrew (Group C) (31 people, 49 screws). All participants completed questionnaires for 14 days after the operation. The patients responded to questions by placing a mark along a 10-cm-long visual analog scale (VAS).ResultsThere were no significant differences in pain and discomfort due to the orthodontic archwire itself, as opposed to the anchorage devices, between all three groups. However, Group A showed significantly higher levels of pain and discomfort after insertion than both miniscrew groups at all periods, and Group C presented prolonged discomfort relative to Group B. At three days after operation, more than 35% in Group A were taking analgesics, compared to significantly lower percentages in Group C (0%) and Group B (7.1%).ConclusionThese results suggest that appropriate skeletal anchorage devices should be selected on a case-by-case basis, considering not only the mechanical effect but also the patients’ pain and discomfort levels.     

Distalization pattern of the maxillary arch depending on the number of orthodontic miniscrews

Objective:To determine the effects of linear force vector(s) from interradicular miniscrews on the distalization pattern of the maxillary arch in adult Class II patients.Materials and Methods:Twenty-five adult patients with mild to moderate Class II dentition and minimal crowding were collected. Either single (group A, n  =  12) or dual (group B, n  =  13) miniscrews were inserted on the posterior interradicular area to deliver a distalizing force to the main archwire. The displacement patterns of maxillary incisors and molars were measured and compared.Results:Significant distalization in the molars and incisors was shown in both groups. Significantly greater distalization and intrusion of the first molar and intrusive displacement of the incisor, together with significant reduction of the mandibular plane, were noted in group B, in contrast to the rotation of the occlusal plane in group A.Conclusions:Interradicular miniscrews predictably induced total arch distalization, leading to the correction of Class II. Additional miniscrews in the premolar area appear to facilitate intrusion and distalization of the entire arch according to the position of the force vectors.     

骨皮质厚度及植入角度对支抗种植钉影响的三维有限元分析

目的:探讨不同骨皮质厚度和不同植入角度对支抗种植钉应力分布的影响及位移变化。方法:建立简单的颌骨及支抗种植钉的三维有限元模型,在不同的骨皮质厚度为0.5mm-3mm和不同的植入角度30°-90°下分别植入支抗种植钉(直径1.6mm、长8mm),在支抗种植钉的头部施加200g力,力的方向与骨面平行,得到模型中的应力和位移,并进行分析。结果:模型中颌骨最大应力均发生在支抗种植钉的颈部,集中分布在1mm的深度范围内。随着骨皮质厚度的增加骨皮质应力减小,当厚度为0.5mm时骨皮质应力较大,从21.00MPa(植入角度70°)到37.88MPa(植入角度30°);骨皮质厚度为1mm时(除外植入角度为≤50°)应力<28MPa。植入角度对骨皮质应力变化影响较大,植入角度为60°、70°时应力较小。颌骨最大位移发生在受支抗种植钉拉压的两侧,支抗种植钉最大位移在其顶部,当骨皮质厚度为0.5mm时,支抗种植钉的位移最大,当骨皮质厚度≥1mm时,骨皮质厚度的变化对位移的影响不显著,植入角度为70°时支抗种植钉位移最小。结论:骨皮质厚度会影响骨皮质和骨松质的应力,临床植入支抗种植钉时应该避开骨皮质较薄的区域,植入区域骨皮质厚度应≥...     

Bone mineral density: Methods of measurement and its influence on primary stability of miniscrews

Objective:To verify whether bone mineral density (BMD) of cortical bone, trabecular bone, and total bone influence the primary stability of orthodontic miniscrews and to verify whether there is a correlation between the measurement of BMD by cone-beam computed tomography (CBCT) and central dual-energy x-ray absorptiometry (DEXA).Materials and Methods:Twenty bovine bone sections were extracted from the pubic and iliac bones from regions with cortical thicknesses of approximately 1 mm. The BMD of the total bone block was evaluated using two methods: CBCT and DEXA. The BMD of cortical, trabecular, and total bone in the region of interest (ROI) were also evaluated by CBCT. After scanning the bone blocks, 20 self-drilling miniscrews (INP®) 1.4 mm in diameter and 6 mm long were inserted into them. The peak implant insertion torque (IT) was registered. After this, the pull-out test (PS) was performed and the maximum force registered. The Pearson correlation test was applied to verify the correlations between variables.Results:The BMD of the total bone block verified by CBCT and DEXA showed a positive and strong correlation (r  =  0.866, P  =  .000). The BMD of the ROI for cortical bone influenced the IT (r  =  0.518, P  =  .40) and the PS of miniscrews (r  =  0.713, P  =  .001, Table 2). However, the total bone BMD (verified by CBCT and DEXA) and trabecular bone BMD presented weak and not statistically significant correlations with primary stability.Conclusions:There was a positive correlation between total bone block BMD measured by DEXA and CBCT. The cortical BMD influenced the IT and PS.     

正畸用微螺钉支抗种植体的稳定性评价

目的:评价正畸用微螺钉支抗种植体的稳定性及影响因素。方法:比较13例患者32颗微螺钉不同的应用设计、植入部位、植入高度、植入次数、牙龈和黏膜反应、加力时机、初期稳定性等因素,应用SAS10.0软件包进行单因素和多因素方差分析,明确影响成功率的因素。结果:32颗微螺钉中,成功29颗,成功率为90.6%。患者年龄与微螺钉的稳定性相关(P=0.04),18岁以下成功率为75%,大于18岁成功率可达100%。植入早期的异常外力影响骨结合,一旦获得骨结合后,长期施加正畸力不会影响微螺钉的稳定。微螺钉周龈炎,甚至化脓性感染(2例)不会破坏已获得的钉-骨间骨结合。植入牙龈的位置,上、下颌间,左、右侧位置间,早期加载与后期加载间的成功率无显著差异。同一个微螺钉多次植入不影响成功率。结论:初期稳定性是影响微螺钉长期稳定的最重要因素,软组织的轻微炎症不会影响骨结合。     

不同时机受力对微种植体支抗稳定性的影响

目的:通过对微种植体-骨组织界面的组织形态学分析,研究不同加载时机对微种植体支抗稳定性的影响.方法:全麻下将48枚微型钛金属种植体植入2只实验Beagle犬双侧上、下颌骨,每只24枚.将48枚种植体分为8组,1组为对照组,负载力值为0g;其余7组为加力组,负载力值为200g.加力组分别在植入术后即刻、第1周、第2周、第3周、第4周、第5周和第6周,用正畸专用镍钛螺旋拉簧对各组微种植钉在相应的时间施加200g的水平拉力.在种植钉植入术后的第6周、第8周和第10周,分别对2只实验犬颈部皮下注射荧光剂四环素、土霉素和钙黄绿素溶液.于植入术后第12周处死实验犬,应用光学显微镜及病理图像分析系统对种植体骨磨片进行纵断面观察,并计算各种植植体-骨界面的骨结合率.各组的骨结合率数据采用SPSS13.0软件包进行统计学处理.结果:不同时机加载各组的骨沉积率与对照组无显著差异.普通光镜下可见种植体-骨界面既有骨结合又有纤维结合,不同时机加载各组的骨结合率无显著差异.结论:植入后不同时机对微种植体支抗加力不会影响其稳定性.     

Effects of washer on the stress distribution of mini-implant: A finite element analysis

Objective:To investigate the biomechanical effects of ‘washer’ designed for improving mini-implant stability.Materials and Methods:Four three-dimensional finite element models of the mini-implant and surrounding bone were constructed with washers in different spike lengths (1.5 mm, 2.0 mm, and 2.5 mm). The force was applied in two directions (45° and 90°). The stress distribution on surrounding bone and the displacement of the mini-implant were analyzed. Plots of tensile stress, compression stress, and displacement were calculated, and maximum values in each category were analyzed.Results:The stress distribution was different between the models with washer and without washer. However, no remarkable differences in stress distribution were observed among the models with washer, regardless of spike length. A significantly greater displacement value was observed in the model without washer compared to the models with washer, but no notable difference in displacement value was found among the models with washer. The plots of the displacement distribution of the models with washer presented notable pattern differences as compared with that of the model without washer.Conclusion:With the use of the washer, a more homogeneous distribution of bone stress and less displacement of the mini-implant can be achieved.     

微型种植体支抗稳定性的临床研究

目的：对微螺钉种植体在正畸支抗中的稳定性进行研究。方法：按微螺钉种植体支抗的标准操作规程对50例各类错畸形采用直丝弓矫治技术配合自攻型微螺钉支抗种植体进行矫治,共种植微螺钉135个,微种植钉的负载期为8～12个月,评价各个临床变量对微螺钉种植体稳定性的影响。结果：微型种植钉的成功率为95.6%,下颌平面角的高低、微螺钉直径、患者口腔卫生状况,对微种植钉的稳定性影响明显,微种植钉的定位及加力情况对微种植钉的稳定性无显著影响。结论：选择较粗的螺钉,对下颌平面角较高的患者采取谨慎设计,严格手术操作,维持好的口腔卫生是微螺钉支抗种植体种植成功及能否稳定行使功能的关键。     

骨密度对正畸支抗稳定性影响的临床研究

目的：研究骨密度对正畸支抗稳定性的影响。方法：选择进行正畸治疗,需要拔除4颗第一前磨牙及弱支抗矫治的安氏Ⅰ类错牙合的健康男性患者212名,年龄18-25周岁,其中支抗失控患者16名,支抗稳定患者196名,通过双能X线骨密度仪测定每位患者4颗第二前磨牙根尖区周围0.5 cm2范围区域的骨密度,并运用统计学方法进行对比分析。结果：经单因素方差分析,两组患者第二前磨牙区域骨密度值具有显著性差异（P<0.05）。结论：骨密度可能是影响正畸支抗稳定性的因素,在正畸支抗设计时应列为参考指标之一。     

Effect of surface treatment on the mechanical stability of orthodontic miniscrews:: A systematic review with meta-analysis

ObjectivesTo provide collective quantitative evidence about the effect of surface treatments on the mechanical stability of orthodontic miniscrews (MSs).Materials and MethodsThe study was registered in PROSPERO (No. CRD42020209652). The research question was defined according to the PICO (population, intervention, control, and outcomes) format. Various research databases were searched for animal and human studies on effects of surface treatment on the mechanical stability of MSs. Both prospective and retrospective in vivo clinical studies published in English were included. The risk of bias was assessed using SYRCLE''s risk of bias tool for animal studies. The meta-analysis was conducted using RevMan 5.4.ResultsA total of 109 articles were identified; 14 were included in the systematic review, and seven studies with sandblasting, acid etching (SLA) methods of surface treatment were included for meta-analysis. The number of study participants ranged from 6 to 24 (total n = 185), with a mean of 13.2. A total of 949 MSs were used with a mean of 67.8. The overall success rate for surface-treated MSs ranged from 47.9% to 100%. Forest plot of removal torque values showed significantly higher values for SLA surface-treated MSs compared with controls with a standard mean difference of 2.61 (95% confidence interval = 1.49–3.72, I² = 85%). Forest plot of insertion torque showed a standard mean difference of –6.19 (95% confidence interval = –13.63–1.25, I² = 98%, P = .10).ConclusionsSurface treatment of MSs improved primary and secondary stability with good osseointegration at the bone-implant surface. However, significant heterogeneity across the studies included in the meta-analysis made it difficult to draw conclusions.     

正畸微种植体稳定性的临床共振频率分析

目的 用共振频率分析法评价正畸微种植体稳定性的临床变化规律,探讨合适的加载时机及加载对微种植体稳定性的影响。方法 选择上颌第一前磨牙减数并需要强支抗的正畸患者14例,分为延期加载组和择期加载组各7例。每例患者在上颌后牙左右颊侧牙槽骨区植入分体式微种植体各1颗,用Osstell种植体稳定性测量仪作共振频率分析,植入后即刻及每周记录微种植体的种植体稳定性系数（implant stability quotients,ISQ值）。延期加载组在第12周加载150 g水平牵引力之前,选出ISQ值稳定的时间点,以此作为择期加载组的加载时机,施加同样大小的正畸力。2组患者均随访至16周,采用SPSS 19.0软件包对数据进行方差分析和t检验。结果 28颗微种植体中,5颗在4周内发生松动而取出,剩余23颗在16周内保持稳定,其中12颗延期加载组微种植体的共振频率分析显示,ISQ值在植入即刻及第1周最高（21.48±5.25）,第2周到第5周逐渐下降,第6周后维持平稳 （11.26±3.36）。11颗择期加载组微种植体在第6周加载牵引力。从第6周至16周,2组微种植体无论加载与否, ISQ 值均无显著变化,2组间也无显著差异（P>0.05）。松动微种植体的初始ISQ值显著小于非松动组。结论 微种植体植入1周后稳定性下降,6周后趋于稳定。6周后加载正畸力对稳定性无影响,而初始稳定性差是微种植体失败的重要原因。     

补骨脂对大鼠正畸后稳定性的影响

目的 探讨补骨脂素对大鼠正畸牙移动后牙周组织改建的影响。方法 选择36只8周龄雄性Wistar大鼠,将其随机分为实验组和对照组2组。在上颌左侧切牙和上颌左侧第一磨牙之间安装拉第一磨牙向近中的加力装置。加力21 d后去除装置,对2组进行药物灌胃处理。实验组大鼠灌服8 mg/（kg·d）补骨脂素溶液,对照组大鼠每天灌服等量生理盐水,连续灌服4周。在去除装置当天和第7、14、21、28天制取大鼠上颌石膏模型,3D扫描获得电子数据,测量并计算复发距离。灌药4周后,心脏灌注处死全部大鼠,分离上颌骨,分离大鼠磨牙及其周围的牙周组织,对切片进行H-E染色和BMP2、BMP4免疫组织化学染色。采用 SPSS 21.0 软件包对数据进行统计学分析。结果 拆除矫治器后,2组均有复发,实验组在第7、14、21、28天的复发率显著小于对照组（P<0.05）。2组复发速度均在第1周最快,第2、3、4周逐渐变慢,实验组在第1周复发速度显著小于对照组（P<0.05）,2组牙周膜和牙槽骨中均有BMP2、BMP4表达,实验组表达强度高于对照组（P<0.05）。结论 补骨脂素能够促进牙周组织中BMP2、BMP4的表达,加速牙周组织改建,有效抑制复发。     

Effect of bone quality and implant surgical technique on implant stability quotient (ISQ) value

PURPOSE

This study investigated the influence of bone quality and surgical technique on the implant stability quotient (ISQ) value. In addition, the influence of interfacial bone quality, directly surrounding the implant fixture, on the resonance frequency of the structure was also evaluated by the finite element analysis.

MATERIALS AND METHODS

Two different types of bone (type 1 and type 2) were extracted and trimmed from pig rib bone. In each type of bone, the same implants were installed in three different ways: (1) Compaction, (2) Self-tapping, and (3) Tapping. The ISQ value was measured and analyzed to evaluate the influence of bone quality and surgical technique on the implant primary stability. For finite element analysis, a three dimensional implant fixture-bone structure was designed and the fundamental resonance frequency of the structure was measured with three different density of interfacial bone surrounding the implant fixture.

RESULTS

In each group, the ISQ values were higher in type 1 bone than those in type 2 bone. Among three different insertion methods, the Tapping group showed the lowest ISQ value in both type 1 and type 2 bones. In both bone types, the Compaction groups showed slightly higher mean ISQ values than the Self-tapping groups, but the differences were not statistically significant. Increased interfacial bone density raised the resonance frequency value in the finite element analysis.

CONCLUSION

Both bone quality and surgical technique have influence on the implant primary stability, and resonance frequency has a positive relation with the density of implant fixture-surrounding bone.     

外力方向对防护牙托性能影响的有限元分析

目的: 运用有限元分析评估外力方向对牙托缓冲能力的影响。方法: 采集仿真模型锥形束CT（CBCT）影像资料,利用MIMICS软件建立分析模型。运用ABAQUS软件模拟研究在牙托厚度不同的情况下（分别为0、1.5、3、4.5和6 mm）,经不同方向外力（撞击方向与牙长轴交角分别为30°、60°、90°和120°）撞击后,牙体表面的应力变化情况,进而评价牙托的缓冲能力。结果: 在研究实验条件下,当牙托厚度较薄时（1.5 mm和3 mm）,与其他方向相比,牙托缓冲效率在60°交角时最低,在120°交角时最高。而在牙托厚度增加后（4.5 mm和6 mm）,牙托缓冲效率在90°交角时最低,在30°交角时最高。外力方向不同时,牙托的应力缓冲效率随着牙托厚度的增加而提高。结论: 外力方向对防护牙托的缓冲能力有一定影响,但其易受牙托厚度的影响。     

Effect of placement angle on the stability of loaded titanium microscrews in beagle jaws

Objective:To evaluate the effect of insertion angle on stability of loaded titanium microscrews in beagle jaws.Materials and Methods:Forty-eight microscrews were inserted at four different angles (30°, 50°, 70°, and 90°) into the intraradicular zones of the mandibular first molars and third premolars of 12 beagles and immediately loaded with a force of 2 N for 8 weeks. Microcomputed tomography (micro-CT) and biomechanical pull-out tests were used to assess osseointegration of the interface.Results:All micro-CT parameters and maximum pull-out force (F_MAX) of the microscrews were affected by insertion angles of microscrews. Higher micro-CT parameters and F_MAX were seen for implants inserted at angles between 50° and 70° (P < .05). Excessive oblique and vertical insertion angles resulted in reduced stability (P < .05).Conclusion:An insertion angle of 50° to 70° is more favorable than excessive oblique or vertical angles to achieve stability of microscrews.