Treatment outcomes of Class II malocclusion cases treated with miniscrew-anchored Forsus Fatigue Resistant Device: A randomized controlled trial

Objective:To evaluate the skeletal, dental, and soft tissue effects of the Forsus Fatigue Resistant Device (FRD) used with miniscrew anchorage and compare them with those of the conventional Forsus FRD.Materials and Methods:This study was carried out on 38 patients. These patients were randomly allocated into three groups. The 14 patients in group 1 (aged 12.76 ± 1.0 years) were treated with the FRD appliance. In group 2, the 15 patients (aged 12.52 ± 1.12 years) received treatment with FRD using miniscrew anchorage, and the 9 patients in group 3 (aged 12.82 ± 0.9 years) received no treatment as a control group. Linear and angular measurements were made on lateral cephalograms before and immediately after Forsus treatment. Data were analyzed statistically using paired t-, ANOVA, and Tukey tests.Results:Class I molar relationship and overjet correction were achieved in both treatment groups. Although mandibular growth was statistically nonsignificant, there was a significant headgear effect on the maxilla. Mandibular incisor proclination, maxillary incisor retroclination, and distalization of maxillary molars were significant in both treatment groups. However, no significant differences were found between the treatment groups.Conclusions:Class II correction was mainly dentoalveolar in both treatment groups. Use of miniscrews with Forsus did not enhance mandibular forward growth nor prevent labial tipping of the mandibular incisors.     

Forsus和Dynamax矫治器对下颌骨生长改形的效果比较

目的比较Forsus矫治器与Dynamax矫治器对下颌骨形态的影响。方法选择30例治疗成功的骨性Ⅱ类错[牙合]患者,15例采用Forsus矫治器治疗,15例采用Dynamax矫治器治疗,以矫治前后的X线头影测量片评价其疗效,并进行对比。结果两种矫治器均能明显增加下颌骨长度,但Dynamax矫治器对下颌平面角的影响更大。结论在选择两种矫治器矫治骨性Ⅱ类错[牙合]患者时应考虑患者的下颌角因素。     

Forsus推上颌第一磨牙向远中瞬时移动趋势的力学仿真分析

目的:构建具有一定粘弹塑性的Forsus推上颌第一磨牙向远中三维有限元模型,仿真模拟Forsus推上颌第一磨牙远中瞬时移动趋势,探讨Forsus远中移动上颌第一磨牙有利的加载方式,为临床应用提供一定的参考依据.方法:选择恒牙早期安氏Ⅱ类错殆畸形男性患者1名,螺旋cT扫描头颅后,经Mimics8.0、Abaqus6.5构建Focus推L颌第一磨牙向远中的三维有限元模型,模拟单纯加载Forsus远中力、加载Focus远中力+抗倾斜力矩、复合加载Forsus远中力+抗倾斜力矩+抗旋转力矩三种不同载衙作用下上颌第一磨牙的瞬时移动过程(加载合力大小300 g,作用点位于冠颊而中心,加载时间为1 s),经Abaqus6.5分析上颌第一磨牙远中移动的有利加载方式.结果:Forsus推上颌第一磨牙向远巾时,不同的加载方式所产生的牙周膜应力分布不同.单纯加载Forsus远中力时,上颌第一磨牙发生较严重倾斜移动;加载Fomus远中力+抗倾斜力矩(Mt/F=9)时,上颌第一磨牙发生较严重扭转;复合加载Focus远中力+抗倾斜力矩(Mt/F=9)4-抗旋转力矩(Mr/F=5)时,上颌第一磨牙牙周膜韧带远中面承受的应力最小,第一磨牙近似远中平动.结论:Forsus导下颌向前时,在上颌第一磨牙处辅以一定的抗倾斜力矩和抗旋转力矩,可获得较有利的磨牙远中平动效果.     

Breakages using a unilateral fixed functional appliance: a case report using The ForsusTM Fatigue Resistant Device

Abstract

Fixed functional appliances are designed to provide a simple non-compliant solution to orthodontic Class II treatment. Molar correction can be achieved very quickly using these appliances, but the clinician should be wary of unexpected breakages. This case report documents such an occurrence using a unilateral fixed functional appliance.     

Forsus矫治器治疗发育高峰后期下颌后缩的疗效评价

目的:评价Forsus矫治器治疗生长发育高峰后期下颌后缩患者的临床效果、颅面软硬组织的改变。方法:应用Forsus矫治器对15例生长发育高峰后期的安氏Ⅱ类下颌后缩畸形患者进行矫治,进行上、下颌尖牙及磨牙间宽度测量,填写问卷调查表和治疗前、后的头影测量侧位片分析。采用SPSS10.0软件包对所得数据进行配对t检验。结果:SNB增加1.42°,ANB角减小1.65°,面突角减小2.12°,颏唇沟深度减小2.27mm,覆盖减小4.98mm,磨牙关系改善3.78mm。上切牙内收,下切牙唇倾;牙弓宽度增大。基本无异物感,不影响口腔功能。结论:Forsus矫治器能够有效促进下颌生长、改善磨牙远中关系及Ⅱ类软组织面型,适用于生长发育高峰后期患者的治疗。     

Forsus矫治器临床应用的研究

Forsus矫治器是一种新型的引导下颌前伸的固定型功能矫治器,对安式Ⅱ类错有很好的矫治效果。该装置可与固定矫治器联合应用,不依赖患者合作,具有独特的优越性,可对上下颌骨均产生作用,主要是抑制上颌生长,有效地促进下颌骨的适应性改建,促进下颌骨在垂直和矢状方向的生长发育,对下颌后缩的安式Ⅱ类错畸形患者的矫治效果尤为明显。现就Forsus矫治器在临床上的应用作一综述,以期对临床治疗有所帮助。     

Incisor inclination changes produced by two compliance-free Class II correction protocols for the treatment of mild to moderate Class II malocclusions

Objective:To compare the changes in incisor inclination between two compliance-free Class II correction protocols for the treatment of mild to moderate Class II malocclusions.Materials and Methods:Among Class II malocclusion patients a total of 38 consecutive patients treated with the Xbow appliance and later with full brackets (XB) were compared to 36 consecutive patients treated with Forsus connected to the archwire while on full brackets (FO). Evaluated cephalometric variables were overjet, overbite, skeletal Class II, lower incisor inclination, and upper incisor inclination. Factors that were analyzed were gender, treatment type, age at start of treatment (T1), and treatment length. Independent t-tests, χ², multiple analysis of variance, and Pearson correlations were applied.Results:No differences in incisor inclination between both treatment protocols were identified. At T1 no statistical difference for any cephalometric variable was demonstrated with regard to gender and treatment type. Gender was also not associated with a different treatment time or age at T1. The mean treatment time was 24.2 months for XB and 30.2 months for the FO group (P  =  .037). XB patients averaged 10 fewer months of fixed edgewise appliances compared to FO patients. Neither gender nor treatment type had any influence on the changes of the evaluated dependent variables between T1 and the end of treatment. Lower incisors proclined more the longer the treatment (P  =  .005). Both overjet and upper incisor inclination were affected by age at T1 (P  =  .001 and P  =  .014, respectively).Conclusions:Both compliance-free Class II correction protocols for the treatment of mild to moderate Class II malocclusions appear to generate the same amount of incisor inclination. Large variability was identified.     

Evaluation of the miniplate-anchored Forsus Fatigue Resistant Device in skeletal Class II growing subjects: A randomized controlled trial

Objectives:To evaluate the use of direct miniplate anchorage in conjunction with the Forsus Fatigue Resistant Device (FFRD) in treatment of skeletal Class II malocclusion.Materials and Methods:Forty-eight females with skeletal Class II were randomly allocated to the Forsus plus miniplates (FMP) group (16 patients, age 12.5 ± 0.9 years), Forsus alone (FFRD; 16 patients, age 12.1 ± 0.9 years), or the untreated control group (16 subjects, age 12.1 ± 0.9 years). After leveling and alignment, miniplates were inserted in the mandibular symphysis in the FMP group. The FFRD was inserted directly on the miniplates in the FMP group and onto the mandibular archwires in the FFRD group. The appliances were removed after reaching an edge-to-edge incisor relationship.Results:Data from 46 subjects were analyzed. The effective mandibular length significantly increased in the FMP group only (4.05 ± 0.78). The mandibular incisors showed a significant proclination in the FFRD group (9.17 ± 2.42) and a nonsignificant retroclination in the FMP group (−1.49 ± 4.70). The failure rate of the miniplates was reported to be 13.3%.Conclusions:The use of miniplates with the FFRD was successful in increasing the effective mandibular length in Class II malocclusion subjects in the short term. The miniplate-anchored FFRD eliminated the unfavorable mandibular incisor proclination in contrast to the conventional FFRD.     

Analysis of Class II patients,successfully treated with the straight-wire and Forsus appliances,based on cervical vertebral maturation status

Objective:To assess skeletal and dental changes in patients successfully treated with the Forsus appliance based on cervical vertebral maturation status.Methods:Forty-seven Class II patients, successfully treated with the Forsus appliance, were divided into peak and postpeak growth groups determined immediately prior to Forsus placement. The mean (SD) ages of the peak and postpeak groups were 13.4 (1.0) and 14.1 (1.3) years, respectively. Superimpositions of initial, Forsus placement, Forsus removal, and final cephalometric radiographs were completed, allowing the measurement of changes during three treatment phases.Results:There were no significant differences between groups during treatment phase 1 (alignment/leveling), with both groups demonstrating a worsening of the Class II molar relationship. However, during treatment phase 2 (Class II correction), patients within the peak group demonstrated significantly higher mean apical base, mandibular and molar changes, and an increased rate of change compared with those in the postpeak group. No significant differences were observed during treatment phase 3 (detail/finishing).Conclusions:Following an initial worsening of the Class II molar relationship as a result of straight-wire appliance effects, Forsus appliance treatment initiated during cervical vertebral maturation status (CS) 3–4 elicits more effective and efficient correction of Class II molar relationships than when initiated during CS 5–6. Data support that these effects are due mainly to maxillary skeletal and dentoalveolar restraint during a period of more rapid mandibular growth.     

Evaluation of the splint-supported Forsus Fatigue Resistant Device in skeletal Class II growing subjects

ObjectivesTo evaluate the use of the Forsus Fatigue Resistant Device (FFRD), supported with bimaxillary splints, in treatment of skeletal Class II malocclusion.Materials and MethodsData from 46 skeletal Class II females who received either conventional Forsus alone (FFRD group) (15 patients, 12.54 ± 0.90 years), FFRD and bimaxillary splints (splint-FFRD group) (15 patients, 12.29 ± 0.82 years), or were untreated controls (16 subjects, 12.1 ± 0.9 years) were retrieved from previous clinical trials. FFRD was inserted onto the mandibular archwire in the FFRD group after leveling and alignment with multibracket appliances. In the splint-FFRD group, Forsus was inserted between fixed maxillary and mandibular splints. Treatment continued until reaching an edge-to-edge incisor relationship.ResultsBoth treatment groups failed to induce significant mandibular skeletal effects compared to the normal growth exhibited by untreated controls. The splint-FFRD group showed significant reduction of SNA (−0.88° ± 0.51°) and ANB (−1.36° ± 0.87°). The mandibular incisors showed significant proclination in the FFRD (9.17° ± 2.42°) and splint-FFRD groups (7.06° ± 3.34°).ConclusionsThe newly proposed splint-supported FFRD was equally effective as the conventional FFRD in treatment of Class II malocclusion with dento-alveolar changes and additional maxillary restricting effect. It has an additional advantage of immediate initiation of the Class II correction.