未治疗的安氏Ⅲ类错[牙合]下颌骨的生长旋转特点

目的：观察未治疗的安氏Ⅲ类错[牙合]患者颈椎骨龄CS1-CS6期下颌骨的生长旋转特点,为安氏Ⅲ类错[牙合]患者的生长改向提供参考。方法：收集安氏Ⅲ类错[牙合]患者329例,男144例,女185例;拍摄头颅定位侧位片,按性别和颈椎CVM分期分组,应用Winceph8．0头影测量软件测量下颌角（ArGo＇Me）、[牙合]平面角（Occlusalp1．to SN）、下颌平面角（Go—Gnto SN）和面高比（S—Go／N—Me）值,数据采用SPSS16．0方差分析后进行组间多重对比（LSD—t检验）。结果：男性安氏Ⅲ类错[牙合]患者SN—OP呈现先升后降趋势,CS3和CS6组间差异有统计学意义（P〈0．05）;在CS4-CS6期,ArGo’Me逐渐减小,S-Go／N—Me逐渐增加,CS4和CS6组间差异明显（P分别为0．041和0．009）。女性安氏Ⅲ类错[牙合]患者SN—OP、SN—GoGn和ArGo＇Me均在CS4-CS5有明显减小（P〈0．05）;S-Go／N—Me在CS4-CS5期增加（P=0．006）。结论：安氏Ⅲ类错骀患者下颌骨生长总体上呈向前上旋转趋势,在CS4期之后旋转明显。提示对安氏Ⅲ类错[牙合]患者进行生长改向治疗时,应考虑到生长发育高峰期之后下颌骨的前上旋转对预后的影响。     

Treatment Effects of Twin-Block and Mandibular Protraction Appliance-IV in the Correction of Class II Malocclusion

Objective:To evaluate the treatment effects of twin-block and Mandibular Protraction Appliance-IV (MPA-IV) in the treatment of Class II division 1 malocclusion.Methods:Fifty North Indian girls with Class II division 1 malocclusion, in the age range of 9–13 years, were chosen. The subjects were divided among a control group (n  =  10), a twin-block group (n  =  25), and an MPA group (n  =  15). Pre–follow-up and post–follow-up lateral cephalograms of control subjects and pretreatment and posttreatment lateral cephalograms of the treatment subjects were traced manually and subjected to a pitchfork analysis.Results:Neither twin-block nor MPA-IV significantly restricted the forward growth of maxilla. Mandibular growth and improvement in the sagittal skeletal relation were significantly greater in the twin-block subjects. Distal movement of the maxillary dentition and mesial movement of the mandibular dentition were more prominent in the MPA-IV subjects. Molar correction and overjet reductions were significantly greater in the treatment subjects (P < .001).Conclusion:Twin-block and MPA-IV were effective in correcting the molar relationships and reducing the overjet in Class II division 1 malocclusion subjects. However, twin-block contributed more skeletal effects than MPA-IV for the correction of Class II malocclusion.     

Extraction of the lateral incisors to treat maxillary protrusion: Quantitative evaluation of the stomatognathic functions

To treat morphological abnormalities, impaction, and severe malposition of the teeth, the lateral incisors are sometimes extracted, followed by orthodontic space closure. This procedure often requires special consideration, not only with regard to esthetics but also for functional issues. However, thus far, few reports that have performed a functional evaluation in such cases. The purpose of this article is to report the successful treatment of an adult patient with a Class II division 1 malocclusion who was treated with extraction of the upper lateral incisors. The female patient, aged 23 years and 6 months, had a chief complaint of maxillary incisal protrusion and crooked teeth. In this patient, the upper lateral incisors were extracted to fulfill the patient''s strong request, followed by orthodontic treatment using edgewise appliances. A high-pull J-hook headgear on the lower dental arch was used to prevent further labial inclination of the lower incisors. The total active treatment period was 37 months. The resulting occlusion and a satisfactory facial profile were maintained during a 4-year retention period. Additionally, this treatment did not affect the stomatognathic functions as assessed by the following criteria: range of the incisal path or condylar motion during maximal open-close movement, protrusive excursion, lateral excursion, and the chewing test. In conclusion, extraction of the upper lateral incisors can be an effective treatment choice when the upper lateral incisors are dwarfed, are nonvital, or demonstrate severe malposition.     

用扩弓和多曲方丝弓技术矫治反(牙合)伴下颌偏斜畸形

目的 探讨扩弓和多曲方丝弓技术在安氏Ⅲ类错(牙合)伴下颌偏斜矫治中的作用机理。方法 选择安氏Ⅲ类错(牙合)伴下颌偏斜患者8例,均采用上颌扩弓技术矫治单侧上颌后牙反(牙合),多曲方丝弓技术不同程度地直立后牙,调整后牙在三维方向的位置,并解除前牙的反(牙合),调整下颌中线。结果 8例Ⅲ类错耠伴下颌偏斜患者均取得良好的矫治效果,矫治后磨牙为中性关系,前牙覆(牙合)覆盖正常。结论 轻度及中度安氏Ⅲ类错(牙合)伴下颌偏斜畸形患者通过上颌的扩弓及多曲方丝弓矫治技术可有效地矫正磨牙关系及下颌偏斜。     

Evaluation of adolescent and adult patients treated with the Carriere Motion Class III appliance followed by fixed appliances

ObjectivesTo determine dentoalveolar and skeletal effects produced in mature patients by the Carriere Motion Class III (CM3) appliance followed by fixed appliances.Materials and MethodsThis retrospective study evaluated 32 patients at three time points: T1 (initial), T2 (removal of CM3), and T3 (posttreatment). Serial cephalograms were traced and digitized, and best-fit regional superimpositions were constructed. Eleven linear and 7 angular variables were measured. The starting forms of the CM3 patients were compared with a sample of untreated subjects with normal occlusions and well-balanced faces.ResultsThe CM3 phase lasted 6.3 months, followed by a phase of fixed appliances lasting 12.9 months; the total duration of treatment was 19.2 months. Minimal skeletal changes were measured sagittally, with only a slight increase in lower anterior facial height observed during treatment. Most treatment changes were dentoalveolar in nature. Wits appraisal increased 4.0 mm during treatment. The molar relationship improved by 6.0 mm during phase I, a value that rebounded slightly during phase II, resulting in an improvement toward Class I of 4.8 mm. Best-fit regional superimpositions revealed anterior movement of upper molars relative to the maxilla and posterior movement of lower molars relative to the mandible.ConclusionsThe Carriere Motion Class III appliance is an effective and efficient method of resolving occlusal problems in minimally growing Class III patients. Primary treatment effects are dentoalveolar in nature with minimal skeletal alterations.     

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目的    探讨球基曲与j钩联合应用技术辅助矫治磨牙支抗丧失效果。方法    2006—2008年厦门市第一医院思明分院拔4颗第一前磨牙进行矫治的患者13例,23颗上颌第一磨牙在采用直丝弓技术矫正治疗过程中出现支抗丧失,联合应用球茎曲与“J”钩对其进行矫治,治疗3～5个月后,观察上颌磨牙向远中、颊向移动情况。结果    13例患者23颗近中移动或倾斜移动的磨牙,联合应用球茎曲与“J”钩治疗后,上颌磨牙平均远中移动（3.97±0.85）mm,颊向平均移动（0.90±0.61）mm,结果有统计学意义（P < 0.05）。13例患者均成功达到磨牙、尖牙一类关系,前牙覆牙合、覆盖正常。结论    联合应用球基曲和“J”钩是一种有效的矫治支抗丧失磨牙向远中方法。     

头帽-肌激动器一下唇挡矫治器治疗安氏Ⅱ错（牙合）的临床研究

目的：研究头帽一肌激动器一下唇挡矫治器治疗生长发育期安氏Ⅱ类1分类错（牙合）对骨骼、牙齿和软组织的影响。方法：选择20例安氏Ⅱ类1分类患者,随机分两组分别采用头帽一肌激动器一下唇挡矫治器和头帽一肌激动器～进行治疗,常规拍摄治疗前后的头颅侧位片进行分析,对结果进行T检验。结果：Pg／OLP显著增加,Si--LiPg明显减少。结论：头帽一肌激动器一下唇挡矫治器组能更好的刺激下颌的发育,明显改善患者侧貌。     

Skeletal and Dental Effectiveness of Treatment of Class II Malocclusion With Headgear: A Systematic Review and Meta-analysis

Objective

To evaluate the skeletal and dental effects of headgear treatment by systematically reviewing the best available scientific evidence.

三段片段弓同时压低和后退上切牙临床研究

目的:评价采用三段片段弓治疗安氏Ⅱ类1分类深覆患者后上颌中切牙、上颌第一磨牙的控制情况.方法:选择12～14岁安氏Ⅱ类1分类高角深覆患者20例,采用三段片段弓,在4个上切牙段阻力中心远中侧2 mm处施加50 g压低力及约20 g后退力,腭杆加强支抗.治疗前及治疗6月后摄X线定位侧位片,并测量和统计.结果:上颌第一磨牙近中移动和垂直伸长量分别为0.60 mm±0.35 mm和0.80 mm±0.52 mm;上颌第一磨牙轴倾角无变化;上中切牙水平后移量及垂直压低量分别为-.20 mm±2.12 mm和3.10 mm±0.54 mm;上中切牙阻力中心后移量及压低量分别为-4.12 mm±1.96 mm和3.20 mm±0.66 mm;上中切牙与腭平面夹角由123.21°±4.26°降低成116.00°±3.96°.结论:三段片段弓技术在同时压低和后退上切牙时,可有效控制后牙支抗,是一种有效的矫治伴有切牙唇倾深覆的方法.     

Clinical effectiveness of chin cup treatment for the management of Class III malocclusion in pre-pubertal patients: a systematic review and meta-analysis

Background

Chin cup is regarded as the oldest orthodontic appliance for the management of Class III malocclusion. To assess its clinical effectiveness in pre-pubertal patients, a meta-analysis on specific cephalometric values is attempted.

Methods

Detailed electronic and hand searches with no restrictions were performed up to July 2014. Only randomized controlled trials (RCTs) and cohort studies, i.e. prospective controlled trials (pCCTs) and (retrospective) observational studies (OS), were included. Analyses were performed by calculating the standard difference in means and the corresponding 95% confidence intervals, using the random effects model. Data heterogeneity and risk of bias assessment of the included studies were also performed. Study selection, data extraction and risk of bias assessment were performed twice. The level of significance was set at P ≤ 0.05 for all tests, except for heterogeneity (P ≤ 0.1).

Results

Seven treated groups from five studies (no RCTs, four pCCTs, one OS) were eligible for inclusion, assessing only the short-term occipital pull chin cup effects. In total, 120 treated patients (mean age: 8.5 to 11 years) compared with 64 untreated individuals (mean age: 7.3 to 9.89 years) were assessed by means of 13 cephalometric variables. The overall quality of these studies was low to medium. In comparison to untreated individuals, the SNB and gonial angles decreased significantly following chin cup use, whereas ANB, Wits appraisal, SN-ML, N-Me and overjet increased. For the rest of the variables, no statistically significant differences were detected.

Conclusions

Although the occipital chin cup affects significantly a number of skeletal and dentoalveolar cephalometric variables, indicating an overall positive effect for the treatment of Class III malocclusion, data heterogeneity and between-studies variance impose precaution in the interpretation of the results.

Electronic supplementary material

The online version of this article (doi:10.1186/s40510-014-0062-9) contains supplementary material, which is available to authorized users.     

Treatment of Class III malocclusion using miniscrew-anchored inverted Forsus FRD: Controlled clinical trial

Objectives:To evaluate the skeletal, dental, and soft tissue changes after the use of miniscrew-anchored inverted Forsus fatigue-resistant device (FRD) in treatment of Class III malocclusion.Materials and Methods:In this controlled clinical trial, 16 patients (9 girls and 7 boys; age 12.45 ± 0.87 years) were consecutively treated with miniscrew-anchored inverted Forsus FRD. This group was compared with a matched control group of 16 untreated patients (8 girls and 8 boys; age 11.95 ± 1.04 years). Miniscrews were inserted bilaterally between the maxillary canine and first premolar. Forsus FRD was selected and inserted in an inverted manner mesial to the mandibular headgear tube and distal to the maxillary canine bracket.Results:Class I molar and canine relationships with positive overjet were achieved in an average period of 6.4 ± 1.46 months. Maxillary forward growth showed a statistically significant increase (SNA°: 1.73 ± 0.53, P < .5), maxillary incisor proclination was statistically significant (U1 to NA°: −0.39 ± 0.33, P > .5), and the lower incisors exhibited significant retroclination (L1 to NB°: 1.65 ± 0.83, P < .5). Significant lower lip retrusion and upper lip protrusion were obvious treatment outcomes (P < .5).Conclusions:The use of miniscrew-anchored inverted FRD could effectively increase maxillary forward growth, but it did not prevent mesial movement of the maxillary dentition. Significant lower incisor retroclination was observed. Significant esthetic improvement of the facial profile was achieved primarily because of lower lip retrusion and upper lip protrusion.     

Class II correction in orthodontic patients utilizing the Mandibular Anterior Repositioning Appliance (MARA)

Objectives:To evaluate skeletal and dentoalveolar changes produced by the Mandibular Anterior Repostioning Appliance (MARA) in the treatment of Class II malocclusion in adolescent patients.Materials and Methods:Lateral cephalograms of 24 patients, mean age 12.40 years, with a Class II malocclusion consecutively treated with MARA were compared with a historical control group. Changes were evaluated using the Pancherz superimposition and grid analysis pre- and posttreatment. Independent sample t-test, Mann-Whitney U-test, and Pearson correlation coefficient analysis were performed.Results:Significant differences were seen between the treatment and control groups during the 12 month period. Improvement in Class II relationship in the MARA group resulted from skeletal and dentoalveolar changes. There was a 7-mm molar correction and a 4.7-mm overjet reduction. There was also an increase in the mandibular base of 3.3 mm with the lower molar and incisor coming forward 2.6 mm and 2.2 mm, respectively. No significant headgear effect was shown on the maxilla. The maxillary incisor position remained unchanged, whereas the molar distalized 1.8 mm. The anterior lower facial height had an overall increase of 2.2 mm.Conclusions:The MARA was successful in achieving a Class I molar relationship and reducing the overjet in Class II malocclusions. This was the result of both skeletal and dentoalveolar changes.     

Characterization of phenotypes of skeletal Class III malocclusion in Korean adult patients treated with orthognathic surgery using cluster analysis

ObjectivesTo characterize the phenotypes of skeletal Class III malocclusion in adult patients who underwent orthognathic surgery (OGS).Materials and MethodsThe sample consisted of 326 patients with Class III malocclusion treated with OGS (170 men and 156 women; mean age, 22.2 years). Using lateral cephalograms taken at initial visits, 13 angular variables and one ratio cephalometric variable were measured. Using three representative variables obtained from principal components analysis (SNA, SNB, and Björk sum), K-means cluster analysis was performed to classify the phenotypes. Statistical analysis was conducted to characterize the differences in the cephalometric variables among the clusters.ResultsClass III phenotypes were classified into nine clusters from the following four major groups: (1) retrusive maxilla group, clusters 7 and 9 (7.1% and 5.5%; severely retrusive maxilla, normal mandible, severe and moderate hyperdivergent, respectively) and cluster 6 (9.2%; retrusive maxilla, normal mandible, normodivergent); (2) relatively protrusive mandible group, cluster 2 (20.9%; normal maxilla, normal mandible, hyperdivergent); (3) protrusive mandible group, clusters 3 and 1 (11.7% and 15.3%; normal maxilla, protrusive mandible, normodivergent and hyperdivergent, respectively) and clusters 8 and 4 (15.3% and 3.7%; normal maxilla, severe protrusive mandible, normodivergent and hypodivergent, respectively); and (4) protrusive maxilla and protrusive mandible group, cluster 5 (11.4%; protrusive maxilla, severely protrusive mandible, normodivergent). Considerations for presurgical orthodontic treatment and OGS planning were proposed based on the Class III phenotypes.ConclusionsBecause the anteroposterior position of the maxilla and rotation of the mandible by a patient''s vertical pattern determine Class III phenotypes, these variables should be considered in diagnosis and treatment planning for patients who have skeletal Class III malocclusion.     

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.     

Duration of the Pubertal Peak in Skeletal Class I and Class III Subjects

Objective:To estimate and compare the duration of the pubertal growth peak in Class I and Class III subjects.Materials and Methods:The data examined consisted of pretreatment lateral cephalometric records of 218 skeletal Class I or Class III subjects (93 female and 125 male subjects) of white ancestry. The duration of the pubertal peak was calculated from the average chronological age intervals between stages CS3 and CS4 of the cervical vertebral maturation in Class I vs Class III groups (t-test).Results:In skeletal Class I subjects, the pubertal peak had a mean duration of 11 months, whereas in Class III subjects it lasted 16 months. The average difference (5 months) was statistically significant (P < .001).Conclusions:The growth interval corresponding to the pubertal growth spurt (CS3–CS4) was longer in Class III subjects than in subjects with normal skeletal relationships; the larger increases in mandibular length during the pubertal peak reported in the literature for Class III subjects may be related to the longer duration of the pubertal peak.     

A three-dimensional soft tissue analysis of Class III malocclusion: a case-controlled cross-sectional study

Objective: The present study used the optical surface laser scanning technique to compare the facial features of patients aged 8–18 years presenting with Class I and Class III incisor relationship in a case-control design.

Materials and methods: Subjects with a Class III incisor relationship, aged 8–18 years, were age and gender matched with Class I control and underwent a 3-dimensional (3-D) optical surface scan of the facial soft tissues.

Results: Landmark analysis revealed Class III subjects displayed greater mean dimensions compared to the control group most notably between the ages of 8–10 and 17–18 years in both males and females, in respect of antero-posterior (P?=?0.01) and vertical (P?=?0.006) facial dimensions. Surface-based analysis, revealed the greatest difference in the lower facial region, followed by the mid-face, whilst the upper face remained fairly consistent.

Conclusion: Significant detectable differences were found in the surface facial features of developing Class III subjects.     

Accuracy,confidence and consistency in diagnosing Class III malocclusion with diagnostic records: a two‐center study

The objective of this study was to determine the accuracy, confidence and consistency in diagnosing the Class III malocclusion in children by diagnostic records. Ten orthodontists from the state of West Virginia and 20 from the state of Ohio were asked to classify the dental and skeletal occlusion of eight patients. Six of the cases were patients with Class III malocclusion. Two cases, one with a Class II division 1 malocclusion and one with a Class I malocclusion, were used as distractors. Diagnosis of these cases was established by four published cephalometric analyses, which served as the ‘gold standard’, to determine the number of correct responses from the participants. Four faculty members were employed to confirm the cephalometric and clinical diagnosis of these cases with a full set of records. Participants were asked to diagnose the cases using only study casts and facial profile photographs for the first time. After an interval of 30 days, the procedure was repeated with the addition of lateral cephalograms and tracings. The accuracy in diagnosing malocclusion was determined by the percentage of correct responses. The level of confidence was determined by calculating the median of a 5‐point graded response utilizing the following confidence values: 1=not at all, 2=slightly, 3=moderately, 4=very, 5=absolutely. Differences between ‘with’ and ‘without’ lateral cephalograms were analyzed non‐parametrically using the Wilcoxon matched‐pairs signed‐ranks test. The results from both centers show the accuracy in dental classification of Class III malocclusion was quite good (83%±17.1% in the West Virginia group and 93%±14.1% in the Ohio group). The accuracy in skeletal classification was poor (72%±16.3 in the West Virginia group and 53%±7.03 in the Ohio group). The addition of lateral cephalograms and tracings did not improve the accuracy of dental or skeletal classification. However, clinicians felt more confident in their diagnoses with the information provided by lateral cephalograms and tracings. The consistency in dental and skeletal classification was fair and poor, respectively. These results suggest that clinicians are not consistent in diagnosing the Class III malocclusion and that skeletal classification of Class III malocclusion in children could be difficult. The addition of lateral cephalograms and tracings do not contribute to the accuracy of diagnosis.     

Chin cup effects using two different force magnitudes in the management of Class III malocclusions

Objectives:To evaluate the dental and skeletal effects of chin cup using two different force magnitudes in the management of Class III malocclusion cases.Materials and Methods:Fifty growing patients (26 males and 24 females) with skeletal Class III and mandibular prognathism were selected. The patients were divided into three groups. Patients in group 1 (n  =  20) were treated with a chin cup and occlusal bite plane using 600 g of force per side. Patients in group 2 (n  =  20) were subjected to the same treatment as in group 1 but using 300 g of force per side. In group 3 (n  =  10) no treatment was performed. For all patients, lateral cephalograms were taken before treatment and after 1 year. Cephalograms were traced and analyzed. The collected data were analyzed statistically using one-way analysis of variance and the Tukey test.Results:In the treatment groups, the SNB angle and ramus height decreased significantly. The ANB angle, Wits appraisal, anterior facial height, mandibular plane angle, and retroclination of the mandibular incisors were significantly increased in comparison to the control group. Utilization of either force showed no significant differences, except that the reduction in the ramus height was significantly greater with the use of higher force.Conclusions:The use of a chin cup improved the maxillomandibular base relationship in growing patients with Class III malocclusion but with little skeletal effect. The utilization of either force had the same effects, except that the higher force had a more pronounced effect in reduction of ramus height.