Evaluation of the effects of skeletal anchoraged Forsus FRD using miniplates inserted on mandibular symphysis: A new approach for the treatment of Class II malocclusion

Objective:To evaluate the skeletal, dentoalveolar, and soft tissue effects of the Forsus Fatigue Resistant Device (FRD) appliance with miniplate anchorage for the treatment of skeletal Class II malocclusion.Material and Methods:The prospective clinical study group included 17 patients (11 girls and 6 boys; mean age 12.96 ± 1.23 years) with Class II malocclusion due to mandibular retrusion and treated with skeletal anchoraged Forsus FRD. After 0.019 × 0.025-inch stainless steel archwire was inserted and cinched back in the maxillary arch, two miniplates were placed bilaterally on the mandibular symphysis. Then, the Forsus FRD EZ2 appliance was adjusted to the miniplates without leveling the mandibular arch. The changes in the leveling and skeletal anchoraged Forsus FRD phases were evaluated by means of the Paired and Student''s t-tests using the cephalometric lateral films.Results:The success rate of the miniplates was found to be 91.5% (38 of 42 miniplates). The mandible significantly moved forward (P < .001) and caused a significant restraint in the sagittal position of the maxilla (P < .001). The overjet correction (−5.11 mm) was found to be mainly by skeletal changes (A-VRL, −1.16 mm and Pog-VRL, 2.62 mm; approximately 74%); the remaining changes were due to the dentoalveolar contributions. The maxillary and mandibular incisors were significantly retruded (P < .001).Conclusion:This new approach was an effective method for treating skeletal Class II malocclusion due to the mandibular retrusion via a combination of skeletal and dentoalveolar changes.     

微型种植体与口外弓治疗成人骨性Ⅱ类错（牙合）的比较张雄单丽华赵士芳黄吉娜毛靖王虎中郭家平王蕾赵今史建陆微型种植体与口外弓治疗成人骨性Ⅱ类错（牙合）的比较

目的 比较微型种植体和口外弓作为强支抗在治疗成人骨性II类错（牙合）中的临床效果.方法 微型种植体支抗组16名,口外弓支抗组10名,收集两组治疗前后的X线头颅侧位定位片,通过X线头影测量比较两组的上下颌骨及上下颌牙齿的各角度、线距的变化.结果 两种方法在对上下颌骨的影响、覆（牙合）覆盖的控制上有相同的效果,但对上颌前后牙的移动上两种方法有明显区别（P〈0.05）,上颌磨牙近中移动量分别为1.1mm（微型种植体组）和2.6mm（口外弓组）,上颌切牙内收量8.9mm（微型种植体组）和5.5mm（口外弓组）.结论 两种加强支抗的方法在正畸治疗中均可获到较好的治疗效果,但微型种植体支抗在上颌磨牙的近中移动和上颌切牙的内收上更具有优势.     

Treatment effects of skeletally anchored Forsus FRD EZ and Herbst appliances: A retrospective clinical study

Objective:To evaluate the skeletal, dentoalveolar, and soft tissue effects of the Forsus FRD appliance with miniplate anchorage inserted in the mandibular symphyses and to compare the findings with a well-matched control group treated with a Herbst appliance for the correction of a skeletal Class II malocclusion due to mandibular retrusion.Materials and Methods:The sample consisted of 32 Class II subjects divided into two groups. Group I consisted of 16 patients (10 females and 6 males; mean age, 13.20 ± 1.33 years) treated using the Forsus FRD EZ appliance with miniplate anchorage inserted in the mandibular symphyses. Group II consisted of 16 patients (9 females and 7 males; mean age, 13.56 ± 1.27 years) treated using the Herbst appliance. Seventeen linear and 10 angular measurements were performed to evaluate and compare the skeletal, dentoalveolar, and soft tissue effects of the appliances using paired and Student''s t-tests.Results:Both appliances were effective in correcting skeletal class II malocclusion and showed similar skeletal and soft tissue changes. The maxillary incisor was statistically significantly more retruded in the skeletally anchored Forsus FRD group (P < .01). The mandibular incisor was retruded in the skeletally anchored Forsus FRD group (−4.09° ± 5.12°), while it was protruded in the Herbst group (7.50° ± 3.98°) (P < .001).Conclusion:Although both appliances were successful in correcting the skeletal Class II malocclusion, the skeletally anchored Forsus FRD EZ appliance did so without protruding the mandibular incisors.     

固定式Twin-block矫治青春期骨性II类错的临床效果评价

目的: 评价固定式Twin-block矫治器的固位效果及治疗青春期骨性Ⅱ类错的临床疗效。方法: 选取26例（男12例,女14例）青春期骨性Ⅱ类1分类错畸形患者（年龄11~13岁,平均11.8岁）,采用固定式Twin-block矫治器引导下颌骨前伸,疗程1年。治疗前、后拍摄头颅定位侧位片,观察患者的骨性、牙性及软组织变化。采用Graphpad Prism 6.0软件对治疗前、后数据进行配对t检验。结果: 治疗中未出现矫治器松动、破坏,所有病例侧貌获得明显改善。发生显著变化的指标有:下颌骨长度和位置（Co-Gn、SNB、ANB、Pog-VL、Pos-VL）,上前牙位置和倾斜度（U1-VL、U1-SN）,下牙列矢状向位置（L1-VL、L6-VL）（P<0.05）;变化不显著的指标有:下颌平面角（MP-SN）,上颌骨位置和长度（SNA、A-VL）,上前牙垂直向位置（U1-HL）,上后牙位置（U6-VL、U6-HL）,下前牙倾斜度（IMPA）,下牙列垂直向位置（L6-MP、L1-MP）（P>0.05）。结论: 固定式矫治器Twin-block可增强下颌支抗,有效促进下颌骨生长,改善患者侧貌。     

Effect of Class III bone anchor treatment on airway

Objectives:To compare airway volumes and minimum cross-section area changes of Class III patients treated with bone-anchored maxillary protraction (BAMP) versus untreated Class III controls.Materials and Methods:Twenty-eight consecutive skeletal Class III patients between the ages of 10 and 14 years (mean age, 11.9 years) were treated using Class III intermaxillary elastics and bilateral miniplates (two in the infra-zygomatic crests of the maxilla and two in the anterior mandible). The subjects had cone beam computed tomographs (CBCTs) taken before initial loading (T1) and 1 year out (T2). Twenty-eight untreated Class III patients (mean age, 12.4 years) had CBCTs taken and cephalograms generated. The airway volumes and minimum cross-sectional area measurements were performed using Dolphin Imaging 11.7 3D software. The superior border of the airway was defined by a plane that passes through the posterior nasal spine and basion, while the inferior border included the base of the epiglottis to the lower border of C3.Results:From T1 to T2, airway volume from BAMP-treated subjects showed a statistically significant increase (1499.64 mm³). The area in the most constricted section of the airway (choke point) increased slightly (15.44 mm²). The airway volume of BAMP patients at T2 was 14136.61 mm³, compared with 14432.98 mm³ in untreated Class III subjects. Intraexaminer correlation coefficients values and 95% confidence interval values were all greater than .90, showing a high degree of reliability of the measurements.Conclusion:BAMP treatment did not hinder the development of the oropharynx.     

Activator与Headgear-Activator治疗作用的研究

目的 比较Activator与Headgear-Activator的治疗作用,探讨两者的作用机理,并评价其临床应用的综合效果。方法 选取36例安氏Ⅱ类错He病例,12例采用Activator治疗,17例采用Headgear-Activator治疗,7例未经治疗作对照。分别摄取治疗前后（对照组采用1年时间间隔）X线头影侧全定位片,用同一参考系统定量分析两种治疗过程中发生的变化。结果 两种治疗方法均能有效纠正Ⅱ类错He,但作用机制不同。结论 Activator和Headgear-Acgivator能有效调节上下颌骨发育的不协调,纠正儿童骨性Ⅱ类错He。Headgear-Activator由于使用高位头帽,可以加强对上颌生长发育,特别是垂直方向的生长发育的控制。同时对牙齿牙槽产生作用,一定程度地控制Activator的一些不良反应,有利于患者牙颌面形态的充分改善及变化的表达。     

Class III camouflage using skeletal anchorage and Pendex appliance

This case report describes the orthodontic treatment for a young female, aged 18 years 4 months, with a Class III malocclusion on the right side, with a combination of a posterior and anterior crossbite. Two rigid orthodontic mini-implants were placed in the retromolar region in order to move the entire lower arch distally with nickel-titanium coil springs. In addition, a Pendex appliance was used to create space and to improve the arch form and the transverse relationship. The active treatment period was 17 months. Normal overjet and overbite were obtained, and facial balance was improved. Although the cephalometric superimposition has demonstrated the effects of dental compensation, the final dental and facial results were satisfactory and stable after the second year in retention.     

Comparison between direct vs indirect anchorage in two miniscrew-supported distalizing devices

Objective:To compare two distalizing devices supported by palatal miniscrews, the MGBM System (MGBM) and the Distal Screw appliance (DS), in dental Class II patients.Materials and Methods:Pretreatment (T1) and postdistalization (T2) lateral cephalograms of 53 Class II malocclusion subjects were examined. MGBM consisted of 29 patients (16 males, 13 females) with a mean pretreatment age of 12.3 ± 1.5 years; DS consisted of 24 patients (11 males, 13 females) with a mean pretreatment age of 11.3 ± 1.2 years. The mean distalization time was 6 ± 2 months for MGBM and 9 ± 2 months for DS. Initial and final measurements and treatment changes were compared by means of a Student’s t-test.Results:Maxillary superimpositions showed that the maxillary first molar distalized an average of 5.5 mm in the MGBM and 3.2 mm in the DS between T1 and T2; distal molar tipping was greater in the MGBM (10.3°) than in the DS (3.0°). First premolar showed a mean mesial movement of 1.4 mm, with a mesial tipping of 4.4° in the MGBM; on the contrary, first premolar showed a distal movement of 2.2 mm, with a distal tipping of 6.2°, in the DS.Conclusions:The MGBM system resulted in greater distal molar movement and less treatment time, resulting in more efficient movement than was associated with the DS; DS showed less molar tipping during distalization.     

Absence of multiple premolars and ankylosis of deciduous molar with cant of the occlusal plane treated using skeletal anchorage

Ankylosis and the absence of premolars are two relatively common conditions encountered in the field of orthodontics. However, the absence of multiple premolars, particularly two adjacent premolars, along with ankylosis of deciduous teeth, is unusual. Herein, we present a case report and discuss some aspects related to these abnormalities. A 15-year-old boy was missing the upper right first and second premolars and the lower right and left second premolars. In addition, the deciduous lower left second molar was ankylosed and in infraocclusion, causing canting of the occlusal plane. The patient was treated with a mini-implant to correct the Class II malocclusion on the left side and a miniplate to correct the cant of the occlusal plan. After treatment, the upper right space was kept closed, with the canine in contact with the first molar, and the lower left space was opened to an implant-prosthetic rehabilitation.     

安氏Ⅱ~1错早期不同矫治方法对关系的影响

目的在生长发育高峰期观察不同矫治方法对骨性Ⅱ~1分类错咬合关系的作用。方法选择非拔牙的骨性Ⅱ~1。分类错儿童30例,随机分为2组,E组用方丝弓配合Ⅱ类牵引治疗16个月。T组用Twin-block功能矫治。治疗及现察16个月。以X线片头影测量分析方法评价疗效。结果两种方法均可改善Ⅱ类关系。功能矫治组主要表现为骨性作用,牙性作用占少部分。而固定矫治组为牙性作用。结论对于生长发育高峰期的骨性Ⅱ~1。分类错儿童进行早期功能矫治更有利于咬合关系的改善。     

Prospective study of dentoskeletal changes in Class II division malocclusion treatment with twin force bite corrector

Objective:To evaluate the dentoskeletal changes of Class II malocclusion treatment with the Twin Force Bite Corrector (TFBC).Materials and Methods:The sample comprised 86 lateral cephalograms obtained from 43 subjects with Class II division 1 malocclusion; the subjects were divided into two groups. The experimental group comprised 23 patients with a mean initial age of 12.11 years who were treated with the TFBC for a mean period of 2.19 years. The control group included 40 lateral cephalograms from 20 Class II nontreated patients, with an initial mean age of 12.55 years and a mean observation period of 2.19 years. The lateral cephalograms were evaluated before and after orthodontic treatment in group 1 and in the beginning and end of the observation period in group 2. t-Tests were used to compare the initial and final cephalometric characteristics of the groups as well as the amount of change.Results:The experimental group presented greater maxillary growth restriction and mandibular retrusion than the control group, as well as greater maxillomandibular relationship improvement and greater labial tipping of the mandibular incisors. The results also showed a greater decrease in overbite and overjet in the experimental group, and there were no statistically significant differences in the craniofacial growth pattern between groups.Conclusions:The TFBC promotes restriction of anterior maxillary displacement without significant changes in mandibular length and position and improvement of maxillomandibular relationship without changes in facial growth and significant buccal tipping of mandibular incisors. Class II correction with the TFBC occurred primarily as a result of dentoalveolar changes.     

Effectiveness of maxillary protraction using a hybrid hyrax-facemask combination: A controlled clinical study

Objective:To evaluate the treatment effects of a hybrid hyrax-facemask (FM) combination in growing Class III patients.Material and Methods:A sample of 16 prepubertal patients (mean age, 9.5 ± 1.6 years) was investigated by means of pre- and posttreatment cephalograms. The treatment comprised rapid palatal expansion with a hybrid hyrax, a bone- and toothborne device. Simultaneously, maxillary protraction using an FM was performed. Mean treatment duration was 5.8 ± 1.6 months. The treatment group was compared with a matched control group of 16 untreated Class III subjects. Statistical comparisons were performed with the Mann-Whitney U-test.Results:Significant improvement in skeletal sagittal values could be observed in the treatment group over controls: SNA: 2.4°, SNB: −1.7°, Co-Gn: −2.3 mm, Wits appraisal: 4.5 mm. Regarding vertical changes, maintenance of vertical growth was obtained as shown by a small nonsignificant increase of FMA and a small significant decrease of the Co-Go-Me angle.Conclusions:The hybrid hyrax-FM combination was found to be effective for orthopedic treatment in growing Class III patients in the short term. Favorable skeletal changes were observed both in the maxilla and in the mandible. No dentoalveolar compensations were found.     

Total arch maxillary distalization using infrazygomatic crest miniscrews in the treatment of Class II malocclusion: a prospective study

ObjectivesTo evaluate treatment effects in Class II patients using infrazygomatic crest (IZC) miniscrews (MS).Materials and MethodsA prospective sample of 25 adolescents (14 females and 11 males; mean age: 13.6 ± 1.5 years) who underwent maxillary dentition distalization treatment with IZC MSs were recruited. Lateral cephalograms and digital models at the beginning of treatment (T1) and after Class II molar correction (T2) were obtained. To compare cephalometric and digital model changes, paired t-test and Wilcoxon test were used. A significance level of 5% was used.ResultsAll patients achieved Class II molar correction over a mean period of 7.7 ± 2.5 months. The IZC MS therapy provided 4 mm of distalization; there was 1.2 mm of intrusion of the first molar with 11.2° distal tipping. The maxillary incisors were retracted 4.7 mm and tipped lingually 13.4°. Overjet and overbite showed a reduction of 3.6 mm and 2.4 mm, respectively. The occlusal plane rotated clockwise 2.8°. The upper lip was retracted by 1 mm and the nasolabial angle increased 5.1°. There was an increase in the interpremolar and intermolar distances.ConclusionsTotal arch distalization of the maxillary dentition using IZC MS was effective in the treatment of Class II malocclusions.     

Cervical vertebra morphology in different skeletal classes: A Three-Dimensional Computed Tomography Evaluation

Objective:To describe cervical vertebra morphology in subjects with different anteroposterior jaw relationships.Materials and Methods:Cone-beam computed tomography images of 31 female subjects aged 19 to 41 years were evaluated. Subjects constituted two groups according to the ANB angle: group 1, skeletal Class II (ANB angle >5); and group 2, skeletal Class III (ANB angle <1). Nine linear measurements and one angular measurement were used to assess the vertebral morphology. The Mann-Whitney U-test was used for statistical analysis.Results:The mean atlas dorsal arch height was significantly shorter in Class II subjects compared with those in Class III (P < .05). The cervical vertebra morphological analysis by cone-beam computed tomography was of comparable precision to three-dimensional computed tomography evaluations. This study confirmed previous findings that Class II subjects have significantly lower atlas dorsal arch heights.Conclusion:The height of the atlas dorsal arch of cervical vertebrae is affected by the anteroposterior skeletal pattern.